February 07 2011

Boot Block Corruption Causes Data Loss in Linux

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The Linux hard drive is partitioned in various partitions/volumes for effective management of your valuable data. Linux hard drive volumes start from the boot block where boot information of the operating system is stored. Last two byes of the Linux boot block contains boot block signature. In some cases, operating system cannot locate boot block signature and the disk cannot be accessed. It makes your significant data inaccessible and leads to data loss. Such cases require you to either restore data from backup or use Linux data recovery software to scan the drive and extract data from it.

For example, you might encounter an error message similar to the following one when you attempt to boot a Linux operating system based computer-

“Master boot record on /dev/hda has been updated.”
Subsequent to the above error, you may also encounter further error message that states-
“No boot signature found on partition”

The system cannot be booted in such cases and you face severe data loss situations. To recover your business-critical data in such cases, you are required to opt for Linux recovery tools.

Grounds of the issue

This problem most frequently occurs if you overwrite the LILO (Linux Loader) boot loader with the MBR (Master Boot Record) that was primarily installed on the /dev/hda disk volume. The boot loader might be overwritten if you try to install it using -M switch. Boot block corruption also results into the same problem.
How to fix boot block corruption problem?
In order to work around this problem, you have to overwrite the Master Boot Record with Linux Loader. It is possible with the help of /sbin/lilo Linux command. This command enables the operating system to overwrite MBR information on the /dev/hdX disk. Alternatively you can use LILO on the /dev/hda2 disk as:

boot=/dev/hda2
lilo -b /dev/hda2
lilo -M /dev/hda
lilo -A /dev/hda 2

In case the above method does not work, you will have to reinstall operating system. As reinstalling the operating system removes all the data from Linux partition, you will need data recovery Linux methods to get your precious data back. Linux data recovery software employs highly-advanced Ext2 recovery algorithms to ensure absolute recovery. The advanced Ext3 recovery software are absolutely safe to use with read-only Linux recovery conduct.

September 04 2010

‘Multiply claimed block’ Linux Error and Recovery

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Linux supports file systems like Ext2, Ext3, ReiserFS etc. They follow hierarchical directory structure, where everything starts from a root directory that is represented by ‘/’. The root directory then expands into sub-directories. As compared to Ext2 file system, Ext3 and ReiserFS are less prone to corruption. It is because they both support file system journaling and can replay journal to recover from unexpected crashes. But in cases of severe corruption, you need to use tools like fsck to repair the file system or ultimately format the partition or volume. To restore the lost data, you need to use an updated and valid data backup. But, if data backup itself gives errors or proves incomplete to deliver the required information, Linux Data Recovery tools can come to the rescue to recover your lost data.

Consider a scenario, you try to start a Linux system and receive a set of error messages as:

“Multiply claimed block”

The boot process fails with this error message and you can’t access the data.

Cause

When your system starts and it doesn’t find the file system in good state, it runs fsck check. This error message is returned by fsck check, when it finds the file system inconsistencies. File system can get corrupt because of unexpected shutdown, virus infection, network errors, hardware issues and other similar reasons.

Solution

To solve the ‘Multiply claimed block’ error, you need to follow these steps:

You need to manually run the fsck command. It can repair file system consistencies like the ones that occur when file system is unmounted or mounted as read-only.

If running fsck doesn’t resolve the issue, you need to reformat the hard disk and reinstall the operating system. This process recreates complete file system structure and also deletes all the data. In such cases, you need to use the recent data backup in order to restore the lost data. But in some cases, data backup can be corrupt or incomplete. To recover data during such circumstances, you can use commercial Data Recovery Linux applications.

Linux  Recovery software are advanced applications that use advanced scanning procedures to safely recover your lost or inaccessible data. Such software are available with interactive interface together with developed features to assist you.

Stellar Phoenix Linux Data Recovery offers powerful Data Recovery Linux solutions. It supports Ext2, Ext3 and ReiserFS file systems based Linux partitions and volumes. The software can be used with almost all Linux distributions as SlackWare, TurboLinux, SUSE, Mandrake etc. It gets installed on Windows (Windows Vista, XP, 2003 and 2000) and the affected Linux hard drive should be connected as slave.

Garry Thomson a student of Mass Communication doing research on linux recovery . He is also a freelancer for http://www.file-recovery-software.net.

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July 29 2010

Bad Block At Beginning Of Inode Table May Cause Data Loss In Linux

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Are you unable to mount your Linux hard drive volume? Are you facing superblock, inode, or file system corruption like error messages while booting your Linux system? Such situations are caused by corruption of Linux hard drive metadata structures. This behavior of Linux operating system renders all your significant data inaccessible and leads to significant data loss. In order to get your mission-critical data recovered, you should opt for Linux Data Recovery solutions through reliable tools.

In a practical scenario, you may encounter the below error messages after copying your data through ddrescue command-line tool and running e2fsck utility:

“Superblock has a bad ext3 journal (inode 8).
Clear? Yes”

Or

“/dev/sdf was not cleanly unmounted, check forced.
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Missing ‘..’ in directory inode 1785876.
Fix? Yes

Pass 3: Checking directory connectivity
Root inode is not a directory; aborting.
e2fsck: aborted
fsck.ext2 /dev/sdf failed (status 0×8). Run manually.”

After the above error message, you can not access your precious data from the hard drive. In order to get your lost data back, and to sort out these errors, you should perform Data Recovery Linux.

Resolution

The problem is caused by bad block at the starting of inode table. You can fix the problem by reconstructing root inode. It is quite easy to reconstruct the root inode, however the problem is that root inode needs to be placed at fixed location and currently a bad block is located there.

Forcing the hard drive to use spare block from its pool is possible, however a bad block is often an indicator of the beginning of hard drive crash. Thus, replacing the affected hard drive with new one is the safest way to recover from this situation. Use ‘dd’ command to copy data from old hard drive to new one. Then run e2fsck to create a new root directory on the new hard drive, and shift all the inodes, respectively.

If the above method does not solve your problem, Linux Recovery applications perform absolute recovery. They use high-end scanning techniques to methodically scan the entire hard drive and get all your precious data recovered. The Linux Data Recovery software come equipped with simple and rich graphical user interface to enable easy recovery.

Stellar Phoenix Linux Data Recovery is the most effective solution for all logical data loss scenarios. The software recovers Ext4, Ext3, Ext2, FAT12, FAT16, and FAT32 file system volumes. It is compatible with all major distributions of Linux operating system such as Red Hat, Debian, Fedora, SUSE, and Ubuntu.

Maria Peter a student of Mass Communication doing research on Data recovery Linux , Linux Data Recovery software And Ext2 Recovery. she is also a freelancer for http://ext3-file-recovery.data-recovery-linux.com/

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