Linux Community Magazine

A Linux file system is a collection of various files and folders, which is stored in a separate disk partition. The entire disk partition is divided into various file system blocks, which are used for storing either the user data or the metadata. The metadata can be referred as the repository that contains the information of the file system. One such metadata structure is the superblock, which is very essential for the health of the Linux system. A file system cannot be mounted if you are not able to access the superblock. This case arises if the superblock is corrupted that can happen because of various reasons such as virus infections, power outages, file system corruption, human errors, etc. In such cases, you should take appropriate corrective measures to recover the file system. If you are not able to resolve the issue, then you should use a third-party Linux data recovery software to perform data recovery of Linux system.

Consider a scenario wherein you have an ext3-partitioned Linux system. When you try to access the partition, you are not able to do so. An error message is displayed, that is:

"/dev/sda2: Input/output error

mount: /dev/sda2: can't read superblock"

Cause:

The cause of this error message is that the superblock has corrupted because of the aforementioned reasons.

Resolution:

You can restore the primary superblock from the various backup copies that the Linux system maintains for such situations. To do this, you need to perform the following steps:

Find out superblock location for /dev/sda2

Check and repair the Linux file system using alternate superblock # xyz, where xyz is the location of the alternate superblock.

Mount file system using mount command viz, # mount /dev/sda2 /mnt

Try to browse and access the file system.

However, if you still are unable to address the situation, then you should use a third-party Linux data recovery software to perform Linux recovery. Such tools are read-only in nature and perform Ext3 Recovery without overwriting the original data.

Stellar Phoenix Linux Data Recovery software is a Data Recovery for Linux software that enables you to perform Linux data recovery for various file system volumes. Apart from ext3 recovery, it is capable of performing Ext2 Recovery and ext4 recovery. In addition, this Linux recovery tool recovers data from various types of hard drives such as SCSI, SATA, EIDE, and IDE. It supports different Linux distributions such as Red Hat, SUSE, Debian, Caldera, Mandrake, Sorcerer, TurboLinux, Slackware, Gentoo, etc. It is compatible with Windows 7, Vista, Server 2003, XP, and Server 2000.