Data Recovery Blog

1. Stellar Phoenix Macintosh Data Recovery Software

Company: Stellar Data Recovery
Supported Mac Type: HFS, HFS+, HFSX, HFS Wrapper and FAT file system volumes
Price: $ 129.00 – $ 349.00

FAT file system support.
Updated Audio & Video preview support (using Qt’s class).
Save Scan Information of Lost Volume list.
Check Destination (not scanned drive) during create image, save scan and saving of files.
Check free space of destination during saving of files/ create image.
Not saving empty folder when filter is applied.
Updated KDC and CRW file format.
Recovers Apple Mail, HTML, FileMaker and Quick Book primary data in exact file format and size.
Recovers exact file size of M4V and 3GP files from Quark Series (QXD Motorola, QXD Intel, QXP Motorola and QXP Intel) processors.
Exact file size of ARW, DNG, ERF file format.
Updated Audio and Video preview support (using Apple Quicktime class).
Refresh Drive List

2. Kernel for Macintosh Data Recovery

Company: Nucleus Data Recovery
Supported Mac Type: HFS, HFS+ partitions
Price: $ 145.00 – $ 249.00

Provides Apple Mac Data Recovery
Recover formatted or deleted partition.
Recover mac data from Lost or Missing Mac folders.
Recognizes and preserves long file names when recovering Mac files & folders.
Full support for IDE, EIDE, SCSI and SATA drives.

3. Recover Data for Mac

Company: Recovery Data
Supported Mac Type: HFS & HFS+ partitions
Price: $ 129.00 – $ 229.00

Disk Initialization
Bad Sector in the disk
Master Directory Block or Volume Header Corruption
Partition Table Corruption
Extents or Extents Overflow file corruption
Catalog File’s node corruption

4. Quick Recovery Mac

Company: Unistal Systems Pvt Ltd.
Supported Mac Type: HFS and HFS + file system
Price: $139.00 – $ 249.00

Mac Data Recovery Software, recovers data from damaged, deleted, or corrupted volumes and even from initialized disks. An exhaustive scan of the drive is performed to locate lost partitions. All found data in the lost partition is then presented in a tree structure so that you can copy your lost files to a working volume. Quick Recovery for MAC is a quick, simple and easy to use Mac data recovery solution that helps you in file recovery in moments of disaster of a disk crash.

Hard Disk Repair

Windows & Linux for Workstation & Servers

DATARECOVERYUNION.COM16 years ago12 years ago08 mins

Windows is generally perceived as being easier to use and administer and mostly with good reason. Most companies choose Windows as their desktop environment and often for their intranet servers too. And yet some companies selected Linux as the desktop and server platform for their massive infrastructure upgrade. In the following paragraphs I will explain the rationale for the decision.

As Sever Machines: Linux VS Windows

For Example: we have embarked on a massive upgrade of our infrastructure with the addition of several 24/7 servers with RAID 1, QA automation machines, order processing machine and redundant internet connections. Each server machine will have RAID 1 and also have hot backup. The choice was between Windows server and Linux. Choose Linux for our server machines for the following reasons:

1. Web server runs on Linux for strategic and security reasons. It only makes sense to have the same server operating system and environment here to simplify maintenance.

2. There should have two machine (one for hot backup) to provide internet connection. The same machine will also host DNS server, Web server and database (for the applications). In short we should make it a near duplicate of our web server machine. The idea is to be able to use this machine to act as a emergency backup of our live server(s). Both the machines (files and database) will be synched several times a day. This machine can also act as backup DNS provider. However this cannot be used to distribute load under normal situations because the upload bandwidth is low as is normal in ADSL and Cable connections. Even then this should provide me with some peace of mind. It only makes sense to have similar configurations in this machine as our current web server machine(s).

3. High cost of Windows server machines for multiple licenses and complicated licensing schemes. The cost of procuring and ensuring that we are compliant is very high for small organizations, not simply in dollar value but also in terms of resource allocation. They will use commodity hardware and they will have to replace them from time to time. However, with Linux they can keep several hot backups and not worry about breaking their licenses. In intend to use Fedora Core as our experience with them has been very positive.

4. RAID 1 support: Both Windows 2003 server and Linux provide software RAID 1 support and also other RAID levels. Unfortunately Windows XP Pro or Windows 2000 do not provide RAID 1 support (mirrored). You must purchase the server version. Both operating systems work with hardware RAID 1. However at this time we choose the software route as it fits well with our strategy of using commodity hardware and having spare backup machines; also it is cheaper without compromising data integrity and availability. Generally in software RAID the performance is expected to be lower. Also in Windows RAID support you will first have to install the operating system on a non-RAID device before RAID can be enabled. Linux provide all the RAID support through software and for free. Their RAID support appears more configurable and all encompassing.

5. The server applications like Apache HTTP server, Subversion, MySQL, DNS Server runs equally well on both platforms.

As Workstations: Linux VS Window

Development & QA Automation Machines

These need to be high end machine. For Example: we use a code editor for php and Eclipse IDE for Java. Both of them are available in Linux as well as Windows XP. Linux comes with Bash shell which is significantly superior to cmd prompt in terms of scripting and task automation. Java and PHP work in Linux as well as on Windows platform.

Blogging Machine

As a blogger we simply need a web browser and a convenient feed reader. There are several PHP-MySQL based feed readers which will suitably serve our requirements. Firefox works fine with Linux as well as Windows. So you see Windows do not have any advantage here.

Email

Any machines require email access. In my experiments Thunderbird came slightly ahead of Microsoft Outlook for pure email purposes especially due to built in Naive Bayesian filter and close integration with Firefox, our web browser. For additional requirements like Calendar, Sunbird is a good choice.

Security

Linux is traditionally ahead of Windows in terms of security. We can get a reasonable protection with iptables alone. ClamAV serves as a decent anti-virus solution for Linux among others. Frankly Internet Explorer will not be missed.

Office Productivity Suite

Star Office competes well against Microsoft Office in this department.

Linux lacks behind in ease of use and requires more upfront training. However the increased security, availability of software RAID 1 (mirroring) and lack of licensing hassles give it a strong advantage over Microsoft Windows. This is just my opinion.

Data Recovery

Top 5 Disaster Recovery Tools

DATARECOVERYUNION.COM16 years ago2 years ago24 mins

Information technology is at the core of almost every organization today. The computer data is one of the invaluable assets for a company. Any computer related disaster can result in irreversible losses for the company. To avoid such disasters out of the blue most companies have a disaster recovery planning as a part of a business continuity planning. To over this important for every organization, you should plan a disaster recovery using with the help of disaster recovery tool. Disaster recovery tools are essentially a part of Disaster Recovery Planning (DRP). The DRP documents chalk out the plan of action prior to, during and following a disaster. The DRP helps a business to minimize its losses caused by a system crash and helps it to recover from a disaster in the shortest possible time by identifying critical systems, processes and methods for restoring the processes.

1. Acronis® True Image Echo™ Server for Windows
For disaster recovery and system migration in both physical and virtual environments, Acronis® True Image Echo Server for Windows delivers greater flexibility and value for SMBs and the Remote Office / Branch Office.

Create an exact Windows server disk image, including the operating system, databases, and applications;
Migrate your systems between any virtual and physical servers quickly and easily

2. UltraBac’s Image based disaster recovery
This image based disaster recovery technology works by taking scheduled snapshots of one or more disk partitions. These images are replica image of the partition frozen at a scheduled time. It ensures a good backup for the files which are open and in use. With the help of this disaster recovery tool the failed machine can be restored using minimum tool. UltraBac offers two versions of disaster recovery tool -UBDR Pro for small to medium businesses and UBDR Gold for larger environments.

3. Living Disaster Recovery Planning System (LDRPS)
This is a business continuity software designed to offer disaster recovery planning. The LDRPS can also be hosted as Software as a Service (SaaS) solution that hosts Strohl Systems applications in the data center. Some of the key features in the LDRPS are customizable best-practices-based plan navigators, customizable reports, dependency maps and location resource management.

4. LBL ContingencyPro Software
This is a web-based browser software tool that provides the best practices for business continuity planning. It also includes hundreds of electronic tools guides, templates, and samples. This tool offers a proven methodology to recover from events of disaster.

5. TAMP DRS (Disaster recovery tool)
This tool creates and distributes business contingency plans that includes disaster recovery. It allows the user to manage and roll up documents, developmental plans, inventory lists, spreadsheets,graphics and flowcharts into one plan. It is completely functional in a disaster afflicted environment.

Hard Disk Repair

Software RAID VS Hardware RAID

DATARECOVERYUNION.COM16 years ago12 years ago010 mins

RAID stands for Redundant Array of Inexpensive Disks which is a technology that employs the simultaneous use of two or more hard disk drives to achieve greater levels of performance, reliability, and/or larger data volume sizes.

There are different levels of RAID. The most popular RAID formats are RAID-1 & RAID-5. However today we will not focus on the various RAID format. Let’s go straight to the differences between software RAID and hardware RAID.

1. Hardware RAID:

A conventional Hardware RAID consists of a RAID controller that is installed into the PC or server, and the array drives are connected to it.

In high end external intelligent RAID controllers, the RAID controller is removed completely from the system to a separate box. Within the box the RAID controller manages the drives in the array, typically using SCSI, and then presents the logical drives of the array over a standard interface (again, typically a variant of SCSI) to the server using the array.

2. Software RAID:

In software RAID the software does the work of RAID controller in place of the hardware. Instead of using dedicated hardware controllers or intelligent boxes, we use particular software that manages and implements RAID array with a system software routine.

3. Comparing Hardware RAID & Software RAID

Portability

OS Portability

Software RAID is not usable across operating systems. So you cannot, for example, use two RAID disks configured in Linux with Windows XP and vice versa. This is big issue for dual booting systems where you will either have to provide a non-RAID disk for data sharing between the two operating system / use hardware RAID instead.

As you know, dual booting is mostly obsolete these days as you can run multiple operating systems on the same machine using virtualization software like VMware & xen.

Hardware Portability

Software RAID
In Linux you can mirror two disks using RAID-1, including the boot partition. If for any reason the hardware goes bad, you can simply take the hard disk to a different machine and it will just run fine on the new hardware. Also with a RAID-1 array, each of the hard disk will have full copy of the operating system and data, effectively providing you with two backups, each of which can be run from a different hardware.Unfortunately in Windows it is not so easy to switch a operating system from one hardware to another, but that is the story of proprietary licenses and we will keep it for another day.

Hardware RAID
Hardware RAID is not so portable. You cannot just swap the hardware to a different machine and hope it will work. You have to find a Motherboard which is compatible with your RAID controller card; otherwise you can kiss your data goodbye. Also there is a bigger issue of problem with the RAID controller itself. If it fails and you cannot get the same controller from the market (and it has probably become obsolete by then), then again you can kiss your data goodbye.

Easy & Speedy Recovery

It may seem trivial but for a busy and loaded server, an easy and speedy recovery, that too inside the operating system without having to reboot is what one can dream of. Imagine if during the peak hours, your RAID system crashes and you are forced to reboot the machine to make changes to it to restore your data! Software RAID’s like in Linux, not only continues working even when the hardware has failed, but also starts restoring the RAID array, should any spare disk be available. All of these happen in the background and without affecting your users. This is where software RAID shines brilliantly.

System Performance

Software RAID uses the CPU to do the work of the RAID controller. This is why high-end hardware RAID controller outperforms software RAID, especially for RAID-5, because it has a high powered dedicated processor. However for low end hardware RAID, the difference may be neglible to non-existent. In fact it is possible for the software RAID perform better than low end hardware RAID controller simply because today’s desktops and workstations are powered by very powerful processors and the task is trivial to them.

Support for RAID Standards

High-end Hardware RAID may be slightly more versatile than Software RAID in support for various RAID levels. Software RAID is normally support levels 0, 1, 5 and 10 (which is a combination of RAID 0 and RAID 1) whereas many Hardware RAID controllers can also support esoteric RAID levels such as RAID 3 or RAID 1+0. But frankly who uses them?

Cost

This is where software RAID again scores over hardware RAID. Software RAID is free. Hardware RAID is moderate to high priced and can put a strain on your budget if deployed widely.

But over the years the cost of hardware RAID has come down exponentially, so it may not be too far when more affordable RAID-5 cards will be built-in on newer motherboards.

Future Proof

Gone are the days when we could associate software RAIDs with bugs and OS problems. Nowadays software RAIDs are almost flawless. We are using software RAID in Linux operating system for several years and haven’t experienced any problem whatsoever. On the contrary, hardware RAID has a single point of failure and that is its hardware controller. If it crashes then your only option is to find another equivalent RAID controller from the market; by this time the model may become obsolete and you may not even find anything compatible. You are as such faced with the haunting prospect of losing all your data, should the RAID controller fail. Software RAID will never become obsolete and will continue to get updated with updated versions of your operating system.

4. In conclusion: Software or Hardware RAID?

In my opinion, software RAID is the way to go for most users, unless you want to extract the very last ounce of performance from your RAID array and budget is not a constraint.

Hard Disk Repair

External Hard Drive Problems

DATARECOVERYUNION.COM16 years ago4 years ago07 mins

Seagate are presently among the most popular and reliable hard disks drives. The disks of the Barracuda ATA 4, ATA 5 and SATA series are relatively fast and advanced models, the only major drawback of which is their considerable heating during operation. Most frequently repairs are called for because of damaged controller components or stuck spindle motors. Disks from the U series also suffer from reading problems due to erratic development of unstable regions on the disk surface which are impossible to eliminate in any conventional way. Data recovery from Seagate HDD’s is a labor consuming process, especially in cases of mechanical damage, and may take up a lot of time, but the chances of success are typically high.

Maxtor, former Quantum, are inexpensive and relatively fast disks, although with quite a few downsides. With time the motor noise increases, the disk tends to develop surface defects and detection failures by the system may occur with increasing frequency. It is not recommended to use these disks for storing critical information and regular backups are just obligatory. While in most cases repair works are attempted for the sole purpose of data recovery, the repaired disk itself can be operational for a long time, except for the slim models which usually fail again within several weeks. The owners of such disks are advised to consider replacement with a more reliable brand. Data from these disks can be recovered successfully, but the repair work must always be trusted to a specialized service shop.

Western Digital disks, although quite widespread in the past, have never been regarded as very reliable. Disks manufactured only three or four years ago are now rarely to be found in a good operating condition. Current models of WD have a satisfactory price/capacity ratio. The new models of WD are called in for repair not very often, maybe also due to their low popularity. A characteristic feature of these disks is the sudden appearance and quick development of bad sectors in different areas of the disk surface. In some cases the disk fails to be detected by the BIOS because of faults in the switching microcircuits. The specific design and circuitry of these disks can sometimes make the task of data recovery after a physical damage too complicated.

IBM (presently Hitachi) are fast and advanced hard disk drives, however not very reliable, especially the glass plate models (DTLA and AVER series). If during startup the disk is not detected or detection is slow, then repair time has certainly come. These disks are highly serviceable and, if treated properly, can continue to operate reliably for a long time. Exception are the cases when the disk repeatedly emits a strong squeaking noise, which is a sign of a serious physical damage of the magnetic surface. Data can still be recovered, but quite complicated situations are possible when the magnetic surface has begun to destroy, thus making the data recovery task more time consuming and problematical. Isolated batches (assembled in Hungary and Romania) with numerous identical defects have also been registered. The production of HDD’s by IBM was discontinued.

Hitachi is successor to the IBM HDD manufacturing division. Most of the remarks about IBM disks are valid for Hitachi as well.

Samsung hard disks are noteworthy for their combination of good performance, high reliability and attractive price. Current models (SP series) are hardly ever called in for repairs, unlike earlier models (Wiener series) most of which are already out of use. Samsung disks usually fail suddenly and for no obvious reason. With the IDE models service problems begin to appear after at least one or two years of operation. Data recovery is very difficult because of the specific design of these disks. Therefore, regular backups are strongly advised.

Fujitsu, while known in the past as expensive and extremely reliable, with the advent of the MPG series these disks now present a sorry sight. The disk begins to shut off during operation and periodically fails to be detected by the system. Next comes full inoperability of the disk. Hopes for spontaneous revival are illusory since these misfortunate events repeat again and again. Data recovery from a damaged disk is in most cases successful. The disk can be repaired, but it is impossible to guarantee its stable operation. Fujitsu is discontinuing the production of hard disks for personal computers.

Data Recovery

Comparison of Software RAID on Windows versus Linux

DATARECOVERYUNION.COM16 years ago12 years ago14 mins

The basic idea of RAID (Redundant Arrays of Inexpensive Disks) is to combine multiple small, independent disk drives into an array of disk drives which yields performance and recoverability exceeding that of a Single Large Expensive Drive (SLED). Redundancy is also provided (unless RAID 0) which allows easy and often automatic recovery from hard disk crash. With the reduction in price of ATA and SATA drives it is often a good idea, even for desktop computers, to setup a RAID 1 system to allow you to function in the event of hard disk failures. In RAID 1 two hard disks (or portions of them) mirror each other. RAID 1 is essential for our environment. I have tested both Windows software RAID facility as well as Linux RAID capability. Linux RAID support is way superior to Windows and should by itself be the reason to switch to Linux. I have given 4 reasons to support my claim below.

Linux supports RAID on block devices. So you can setup RAID between two partitions on the same hard disk or even on two RAID 0 arrays, effectively creating RAID 10 array. Windows simply supports RAID 0 and GBOD (known as linear on Linux) only for non-server users. Linux support all RAID variants. Even Windows server doesn’t support the intermediate RAID variants.

In Linux as well as Windows you can create RAID arrays spanning machines.

In Windows you cannot install the operating system on RAID. In Linux you can even install the operating system on RAID file system. This means if one of the hard disk dies you can easily boot from the other hard disk (assuming you transferred the MBR earlier).

If you have spare hard disks, Linux will automatically configure it and add to the RAID array, should one of the RAID disks fail. This is to my knowledge not possible in Windows.

Linux RAID can be easily configured during installation. All the partitions (/, /opt and even swap) can and should be RAID enabled. Windows RAID is harder to configure and is done after installation of the OS, from disk management.

Comprehensive RAID support by itself (not to mention security) should be reason enough for SMB servers to switch to / use Linux.

Hard Disk Repair

Linux Configuration Files

DATARECOVERYUNION.COM16 years ago4 years ago015 mins

–profile
–System wide environment and startup script program.

/dev/MAKEDEV
The /dev/MAKEDEV file is a script written by the system administrator that creates local only device files or links such as device files for a non-standard device driver.

/etc/aliases
Where the user’s name is matched to a nickname for e-mail.

/etc/bootptab
The configuration for the BOOTP server daemon.

/etc/crontab
Lists commands and times to run them for the cron deamon.

/etc/dhcpd.conf
The configuration file for the DHCP server daemon.

/etc/ethers
File for RARP mapping from hardware addresses to IP addresses. See the man page ethers(5).

/etc/exports
The file describing exported filesystems for NFS services.

/etc/fdprm
The floppy disk parameter table. Describes the formats of different floppy disks. Used by setfdprm.

/etc/filesystems
Can be used to set the filesystem probe order when filesystems are mounted with the auto option. The nodev parameter is specified for filesystems that are not really locally mounted systems such as proc, devpts, and nfs systems.

/etc/fstab
Lists the filesystems mounted automatically at startup by the mount -a command (in /etc/rc or equivalent startup file).

/etc/group
Similar to /etc/passwd but for groups rather than users.

/etc/groups
May contain passwords that let a user join a group.

/etc/gshadow
Used to hold the group password and group administrator password information for shadow passwords.

/etc/host.conf
Specifies how host names are resolved.

/etc/hosts
List hosts for name lookup use that are locally required.

/etc/HOSTNAME
Shows the host name of this host. Used for support of older programs since the hostname is stored in the /etc/sysconfig/network file.

/etc/inittab
Configuration file for init, controls startup run levels, determines scripts to start with.

/etc/inetd.conf
Sets up the services that run under the inetd daemon.

/etc/issue
Output by getty before the login prompt. Description or welcoming message.

/etc/issue.net
Output for network logins with LINUX version

/etc/ld.so.conf
Configuration file for ld.so, the run time linker.

/etc/lilo.conf
Configuration file for LILO.

/etc/limits
Limits users resources when a system has shadow passwords installed.

/etc/localtime
In Debian the system time zone is determined by this link.

/etc/login.defs
Sets user login features on systems with shadow passwords.

/etc/logrotate.conf
Configures the logrotate program used for managing logfiles.

/etc/magic
The configuration file for file types. Contains the descriptions of various file formats for the file command.

/etc/motd
The message of the day, automatically output by a successful login.

/etc/mtab
A list of currently mounted file systems. Setup by boot scripts and updated by the mount command.

/etc/named.conf
Used for domain name servers.

/etc/networks
Lists names and addresses of your own and other networks, used by the route command.

/etc/nologin
If this file exists, non-root logins are disabled. Typically it is created when the system is shutting down.

/etc/nsswitch.conf
Name service switch configuration file.

/etc/passwd
The user database with fields giving the username, real name, home directory, encrypted password and other information about each user.

/etc/printcap
A configuration file for printers.

/etc/profile, /etc/cshlogin,/etc/csh/cshrc
Files executed at login or startup time by the Bourne or C shells. These allow the system administrator to set global defaults for all users.

/etc/protocols
Describes DARPA internet protocols available from the TCP/IP subsystem. Maps protocol ID numbers to protocol names.

/etc/rc or /etc/rc.d or /etc/rc?.d
Scripts or directories of scripts to run at startup or when changing run level.

/etc/rc.d/rc0.d
Contains files used to control run level 0. Usually these files are softlink files.

/etc/rc.d/rc1.d
Contains files to control run level 1. Scripts beginning with an S are for start, K for kill.

/etc/rc.d/rc.sysinit
Init runs this when it starts.

/etc/resolv.conf
Configures the name resolver, specifying the address of your name server and your domain name.

/etc/securetty
Identifies secure terminals from which root is allowed to log in.

/etc/services
Lists the network services that the system supports.

/etc/shadow
Shadow password file on systems with shadow password software installed. Shadow passwords move the encrypted password files from /etc/passwd to /etc/shadow which can only be read by root.

/etc/shadow.group
Systems with shadow passwords may have this file.

/etc/shells
Lists trusted shells. The chsh command allows users to change their login shell to shells listed only in this file.

/etc/skel/.profile
Can be used by administrator to set the editor environment variable to some editor that is friendly to new users.

/etc/sudoers
A list of users with special privileges along with the commands they can execute.

/etc/smb.conf
The configuration file for setting up Samba services.

/etc/sysconfig/amd
Used to configure the auto mount daemon.

/etc/sysconfig/clock
Used to configure the system clock to Universal or local time and set some other clock parameters.

/etc/sysconfig/i18n
Controls the system font settings.

/etc/sysconfig/init
This file is used to set some terminal characteristics and environment variables.

/etc/sysconfig/keyboard
Used to configure the keyboard.

/etc/sysconfig/mouse
This file is used to configure the mouse.

/etc/sysconfig/network-scripts/ifcfg-interface
Defines a network interface.

/etc/sysconfig/pcmcia
Used to configure pcmcia network cards.

/etc/sysconfig//routed
Sets up dynamic routing policies.

/etc/sysconfig/static-routes
Configures static routes on a network.

/etc/sysconfig/tape
Used for backup tape device configuration.

/etc/X11/XF86Config
The configuration file for the X server.

/etc/syslog.conf
Configuration file for the syslogd daemon.

/etc/termcap
The terminal capability database. Describes by what “escape sequences” various terminals can be controlled. See terminfo, termcap, curs_termcap man pages.

/etc/terminfo
Details for terminal I/O.

/etc/usertty
This file is used to impose special access restrictions on users.

$HOME/.bashrc
User aliases, path modifier, and functions.

$HOME/.bash_profile
Users environment stuff and startup programs.

$HOME/.bash_logout
User actions to be done at logout.

$HOME/.hushlogin
When this file exists in the user’s home directory, it will prevent check for mail, printing of the last login time, and the message of the day when the user logs in.

$HOME/.inputrc
Contains keybindings and other bits.

$HOME/Xrootenv.0
Has networking and environment info.

/proc/cpuinfo
Information about the processor such as its type, make and performance.

/proc/devices
A list of devices configured into the currently running kernel.

/proc/dma
Shows which DMA channels are being used at the moment.

/proc/filesystems
Filesystems that are configured into the kernel. The file used to detect filesystems if the /etc/filesystems does not exist.

/proc/ioports
Shows which I/O ports are in use at the moment.

/proc/interrupts
Shows which interrupts are in use and how many of each there have been.

/proc/kcore
An image of the physical memory of the system.

/proc/kmsg
Messages output by the kernel. These are also routed to syslog.

/proc/ksyms
Symbol table for the kernel.

/proc/loadavg
The load average of the system.

/proc/meminfo
Information about memory usage, both physical and swap.

/proc/modules
Which kernel modules are currently loaded.

/proc/mounts
Contains information on filesystems currently mounted, similar to /etc/mtab

/proc/net
Contains status information about network protocols.

/proc/self
A symbolic link to the process directory of the program that is looking at /proc. When 2 process look at proc, they get different links.

/proc/stat
Various statistics about the system such as the number of page faults since the system was booted.

/proc/uptime
The time the system has been up.

/proc/version
The kernel version.

/tmp/fvwmrca01339
FVWM-M4 defines. Contains networking, Xwindows, other setup info.

/usr/lib/zoneinfo
Time zone datafiles are stored here on the Debian system

/var/log/lastlog
Used by finger to tell when a user was last logged in.

/var/log/wtmp
Binary info on users that have been logged on. The last command uses this info.

/var/run/utmp
Contains information about users currently logged in. Who and w commands use this file.

/var/named/root.hints
Used for domain name server. Placed here optionally, but this is the normal location.

/var/named/*
Files used by domain name server. Placed here optionally, but this is the normal location.

/var/log/btmp
Used to store information about failed logins. This file must be first created to activate it.

/var/log/lastlog
Contains information about the last time a login was done on the system. Works with lastb(1).

/var/log/maillog
The normal system mail log file.

/var/log/messages
The main system message log file.

var/log/secure
System tracking of user logins. Check this file periodically.

/var/spool/mail
Where mailboxes are usually stored.

Hard Disk Repair

Linux File Structure

DATARECOVERYUNION.COM16 years ago4 years ago05 mins

Linux file structure files are grouped according to purpose. Ex: commands, data files, documentation. Parts of a Unix directory tree are listed below. All directories are grouped under the root entry “/”.

root – The home directory for the root user
home – Contains the user’s home directories along with directories for services

ftp
HTTP
samba
george

bin – Commands needed during bootup that might be needed by normal users
sbin – Like bin but commands are not intended for normal users. Commands run by LINUX.
proc – This filesystem is not on a disk. It is a virtual filesystem that exists in the kernels imagination which is memory.

1 – A directory with info about process number 1. Each process has a directory below proc.

usr – Contains all commands, libraries, man pages, games and static files for normal operation.

bin – Almost all user commands. some commands are in /bin or /usr/local/bin.
sbin – System admin commands not needed on the root filesystem. e.g., most server programs.
include – Header files for the C programming language. Should be below /user/lib for consistency.
lib – Unchanging data files for programs and subsystems
local – The place for locally installed software and other files.
man – Manual pages
info – Info documents
doc – Documentation
tmp
X11R6 – The X windows system files. There is a directory similar to usr below this directory.
X386 – Like X11R6 but for X11 release 5

boot – Files used by the bootstrap loader, LILO. Kernel images are often kept here.
lib – Shared libraries needed by the programs on the root filesystem

modules – Loadable kernel modules, especially those needed to boot the system after disasters.

dev – Device files
etc – Configuration files specific to the machine.

skel – When a home directory is created it is initialized with files from this directory
sysconfig – Files that configure the linux system for devices.

var – Contains files that change for mail, news, printers log files, man pages, temp files
file

lib – Files that change while the system is running normally
local – Variable data for programs installed in /usr/local.
lock – Lock files. Used by a program to indicate it is using a particular device or file
log – Log files from programs such as login and syslog which logs all logins and logouts.
run – Files that contain information about the system that is valid until the system is next booted
spool – Directories for mail, printer spools, news and other spooled work.
tmp – Temporary files that are large or need to exist for longer than they should in /tmp.
catman – A cache for man pages that are formatted on demand

mnt – Mount points for temporary mounts by the system administrator.
tmp – Temporary files. Programs running after bootup should use /var/tmp.

Data Recovery

Raid Data Recovery Softwares

DATARECOVERYUNION.COM16 years ago12 years ago05 mins

1. RAID Reconstructor
Company: Runtime Software
Supported RAID Type: RAID 0, RAID 5
Supported Working Modes: Automatic Analysis

Runtime’s RAID Reconstructor will help you recover data from broken: RAID Level 5 Array consisting of 3 to 14 drives, RAID Level 0 Array (Striping) consisting of 2 to 14 drives. Even if you do not know the RAID parameters, such as drive order, block size and direction of rotation, RAID Reconstructor will analyze your drives and determine the correct values. You will then be able to create a copy of the reconstructed RAID in a virtual image (.vim), an image file (.img) or on a physical drive.

2. DiskInternals Raid Recovery
Company: DiskInternals Data Recoverysoftware
Supported RAID Type: RAID 0, 1, JBOD, RAID 5, and 0+1
Supported Working Modes: Automatic Analysis

Recover corrupted RAID arrays in a fully automatic mode. Raid Recovery is the first tool to automatically detect the type of the original RAID array while still allowing for fully manual operation. Raid Recovery is no doubt a highly valuable tool for users of all types of RAID arrays, whether hardware, native, or software. The drag-and-drop user interface allows specifying parts of the RAID array by simply dragging and dropping icons representing the disks.

3. Quick Recovery RAID
Company: Unistal Immortalizing Information
Supported RAID Type: RAID 0, RAID 5
Supported Working Modes: Manual Analysis

Quick Recovery RAID is a do-it-yourself non-destructive raid data recovery software. There are just two steps to perform the complete operation. Analysis, Select & Save. Analysis is the most important aspect of data recovery. Quick Recovery RAID’s unique Guided File Excavation Technology (GFETCh) helps in locating files and folders lost behind overwritten partitions too.

4. RAID Recovery Presentation
Company: R-Studio
Supported RAID Type: RAID 0, RAID 1, RAID 5
Supported Working Modes: Manual Analysis

R-Studio detects and treats valid software or hardware RAIDs as regular drives/volumes. But what to do if you have only drives or drive images of a faulty RAID? R-Studio can still help you to get the data back provided that the drives necessary for the RAID to operate are working or you have the images of those drives. The number of drives enough to get data back depends on the RAID layout. For example, for a mirror (RAID 1) of two drives, at least one must be valid, whereas for a RAID5 of 3 disks, the number of valid drives should be two.

5. RAID recovery
Company: Zero Assumption Recovery
Supported RAID Type: RAID 0, RAID 5
Supported Working Modes: Manual Analysis

This tutorial describes the data recovery procedure used to recover a RAID0 or RAID5 array if the controller failed and the array parameters are lost Windows software-based RAID configuration data is damaged.

6. Getway Raid Recovery
Company: Getway Recovery LTD
Supported RAID Type: RAID 0, Raid 5,Raid 5E,Raid 5EE,Raid 6
Supported Working Modes: Smart Mode,Manual Mode,User-define Mode

Getway Raid Recovery is the professional raid recovery software which can extract data from multiple Hard disks in a RAID system, and rebuild the correct data. It can get data back from various types of arrays, including RAID 0, RAID 5, RAID 5E, RAID 5EE and RAID 6.

Data Recovery

Raid 1 Data Recovery

DATARECOVERYUNION.COM16 years ago12 years ago013 mins

1. Raid 1 Data Recovery FAQ

Q: What is the definition of a “RAID 1” volume?
A: “RAID 1” refers to a “Redundant Array of Inexpensive (or Independent) Disks” that have been established in a Level 1, or mirrored, drive set. A RAID 1 volume is a set of disk drives that are configured for data to be written to 2 volumes simultaneously. This configuration provides complete data redundancy in the event of a drive failure.

Q: What is meant by the term “mirroring”?
A: Within a mirroring (RAID 1) volume, the exact same information that is written to one disk is also written to a second disk, creating a “mirror image”, or clone, of the orginal hard drive.

Q: What number of drives are needed for a RAID 1 volume?
A: A minimum of at least two (2) hard drives are required to create and maintain a RAID 1 volume. Unlike some other RAID configurations, RAID 1 volumes require an even number of drives to be used.

Q: What are the differences between “hardware” and “software” RAID 1 configurations?
A: With a software-based RAID 1 volume, the hard disk drives use a standard drive contoller and a software utility provides the management of the drives in the volume. A RAID 1 volume that relies on hardware for management will have a physical controller (either as an expansion card or as a part of the motherboard) that provides for the mirroring of data across the hard drives in the volume.

Q: What are the positive reasons for configuring drives as a RAID 1?
A: A RAID 1 (mirroring) set will provide redundancy, or protection against one of the drives failing during use. With a RAID 1 disk volume, information is written to the first drive and then to a second (or “mirror”) drive at the same time. If one of the hard drives in the mirror volume fails, the remaining hard drive can be placed in service as a single drive with no loss of information. Similar to a RAID 0 (striped) volume, RAID 1 volumes require a minimum of two (2) drives.

Q: What are the arguments against RAID 1 configurations?
A: RAID 1 (mirroring) results in loss of half of the physical storage capacity of the drives comprising the volume. For example, if two (2) 500GB hard drives are configured as a RAID 1 volume, only 500GB is available for data storage. Using the same drives in a RAID 0 (striped) configuration, total data storage would equal 1000GB (or approximately 1 terabyte). Also, if damaged or corrupted data is written to one drive, it is also written to the second drive. Many people mistakenly assume that they are totally protected against data loss with a RAID 1 volume, but nothing could be further from the truth. A RAID 1 volume provides a measure of protection against data loss, but it does not eliminate the need for regular backup of critical data.

Q: Can RAID 1 be combined with another type of RAID, such as RAID 0?
A: The combination of a mirrored configuration with striping added is referred to as RAID 1+0 (also called RAID 10). In this scenario, the configuration will provide mirroring (RAID 1) across two (2) or more drives and will “stripe” the data in real-time to a second mirrored drive set. This unique combination will provide data redundancy and some speed advantages, but it does so at the expense of usable storage space. A volume established as a RAID 1+0 volume provides a little more data protection than a RAID 0+1, and will need four (4) hard drives at a minimum to be configured.

Q: Can data be recovered from a re-formatted RAID 1 volume?
A: Many times information is still recoverable, depending on how the drives were re-formatted. A high-level re-format (using Windows, for example), will create what will appear to be a new “clean” volume – but the original data will still be on the disk in the “free and available” space. A low-level format routine (as performed using the controller software) will overwrite every sector, and in the process destroys the original data.

Q: Could data recovery software utilities be used to recover my RAID 1?
A: Perhaps, but it wouldn’t be the safest approach. Most data recovery software will require the read / write heads to constantly travel over areas of the original disk that, if there is any physical damage, could render the surfaces useless and beyond recovery. The safest method of recovering data from a failed or corrupted RAID 1 volume (or with any storage device) is to create a block-level copy of every sector on each hard drive. The copied image is then used to reconstruct the original volume and rescue the required files and directories. This approach, while more time consuming, maintains and preserves the physical integrity of the drive media and limits the number of times that the original drive needs to be accessed.

Q: With RAID 1, if both mirrored drives fail, can data still be recovered?
A: In many situations, data will be recoverable. The quality and integrity of the data recovered will depend on the extent of the damage incurred to each failed storage device. If the mirrored volume was operating properly up to the point of failure, then there should be identical copies of the data on at least two (2) drives which will provide 2 chances to recover the same data.

2. How Raid 1 Data Recovery?

RAID 1 creates an exact copy (or mirror) of a set of data on two or more disks. This is useful when write performance is more important than minimizing the storage capacity used for redundancy. This is thought to be a foolproof method of data protection, but we commonly receive RAID 1 arrays that have failed due to:

corrupted mirrors

bad data from one drive moves to the other drive

mirror breaks, and does not allow system to boot

improper rebuild

The array can only be as big as the smallest member disk, however. A classic RAID 1 mirrored pair contains two disks, which increases reliability by a factor of two over a single disk, but it is possible to have many more than two copies. Since each member can be addressed independently if the other fails, reliability is a linear multiple of the number of members. To truly get the full redundancy benefits of RAID 1, independent disk controllers are recommended, one for each disk. Some refer to this practice as splitting or duplexing.

When reading, both disks can be accessed independently. Like RAID 0 the average seek time is reduced by half when randomly reading but because each disk has the exact same data the requested sectors can always be split evenly between the disks and the seek time remains low. The transfer rate would also be doubled. For three disks the seek time would be a third and the transfer rate would be tripled. The only limit is how many disks can be connected to the controller and its maximum transfer speed. Many older IDE RAID 1 cards read from one disk in the pair, so their read performance is that of a single disk. Some older RAID 1 implementations would also read both disks simultaneously and compare the data to catch errors. The error detection and correction on modern disks makes this less useful in environments requiring normal commercial availability. When writing, the array performs like a single disk as all mirrors must be written with the data.

RAID 1 has many administrative advantages. For instance, in some 365*24 environments, it is possible to “Split the Mirror”: declare one disk as inactive, do a backup of that disk, and then “rebuild” the mirror. This requires that the application support recovery from the image of data on the disk at the point of the mirror split. This procedure is less critical in the presence of the “snapshot” feature of some filesystems, in which some space is reserved for changes, presenting a static point-in-time view of the filesystem. Alternatively, a set of disks can be kept in much the same way as traditional backup tapes are.