Linux Community Magazine

In Linux systems, all the system processes are carried out by the "init" (short for initialization) program. It runs as a daemon in the system and, usually, has process ID (PID) 1. During the boot process, 'init' is the last process to be executed. Sometimes, the system is unable to boot properly, as it cannot find 'init'.

This may happen if the 'initrd' (initial ramdisk) file system is corrupted because of various reasons such as file system corruption, virus infection, accidental system shutdown due to power surges or system crash, etc.

To overcome this situation, you may need to format the system, reinstall Linux and use the updated backup of the system. However, if you are unable to bring it back to normal then you should consider using a Linux Recovery tool.

Consider a scenario wherein you have a Linux system. You switch on the system, but it stops at the boot process. An error message is displayed, that is:

"Kernel panic: No init found. Try passing init= option to kernel."

The error message suggests that system is unable to find initrd.

Cause:This situation may have occurred because of the following causes:* The 'initrd' statement is not present in GNU Grub (GRand Unified Bootloader) prompt or in Grub.conf file.* The kernel statement parameter 'root' does not point to valid hard disk or hard disk partition.* The 'initrd' file is either deleted or corrupted.

Resolution:To address this issue, you should perform following measures:* First of all, ensure that you have used the correct 'initrd' for GNU Grub that would be passed to the kernel.* Change the root parameter to the one that contains the root (/) folder. For example, 'root=/dev/hda3 if /dev/hda3 is your root partition.* If the 'initrd' file is damaged or deleted, use Linux rescue disk.* Use "chroot /dev/hdxy", where 'x' refers to the hard disk letter and 'y' refers to the partition number, command to change the root to your hard disk

If the aforementioned measure does not bring the system to its correct stage, then you should consider using a Linux Data Recovery tool to recover lost data. These tools facilitate data recovery for Linux systems using sophisticated algorithms to recover lost data.

Stellar Phoenix Linux Data Recovery software is an efficient tool that recovers files, folders, and hard drive volumes. This read-only tool recovers data from various file systems such as Ext4, Ext3, Ext2, FAT32, FAT16, and FAT12. It is compatible with most of the Linux distributions such as Red Hat, SUSE, Debian, Caldera, Mandrake, Sorcerer, TurboLinux, Slackware, Gentoo etc.

Are you finding difficulties in mounting your Linux system disk? The problem could be due to corruption in the file system. To address such issues, Linux OS provides fsck utility. It is a command-line utility, which checks integrity and consistency of the Linux file system. In addition, it finds errors and fixes them, if possible. However, if you run this utility on a mounted file system, then you may not be able to access the data at all. In such cases, you should use a third-party Linux data recovery software to perform data recovery Linux system.

Consider a scenario wherein you have accidentally run fsck on a mounted Linux OS. The inode root gets damaged and all inodes start calling similar blocks. When you try to mount the volume after fsck, the following error message is discovered:

"Mount: wrong fs type, bad option, bad superblock on /dev/hda1, missing codepage or helper program, or other error. In some cases useful info is found in syslog - try dmesg | tail or so"

When you run dmesg, as suggested in the error message, another error message may be displayed, that is:

"ext3-fs: corrupt root inode, run e2fsck"

And when you run e2fsck, yet another error message is displayed, that is:

"Root inode is not a directory. Clear?"

Once you press 'Y' and proceed with the process, the parent entry of each inode from the root directory will be deleted. The root inode will attempt to recover but if it fails, another error message will be displayed, that is:

"Cannot Allocate Root Inode"

After this error message, you will not be able to access your system.

Cause:

This behavior is caused due to corruption of the file system, superblock, root inode, or any other Linux data structure. Because of this, the OS cannot locate the hard disk volumes.

Resolution:

To sort out this problem and perform Linux data recovery, you should reformat the hard disk and reinstall the Linux operating system. However, that would invariably mean that your valuable data will be lost. In such cases, you should use a third-party Linux recovery to Recover Linux lost data. Such tools are able to recover lost data safely by using fast yet sophisticated scanning algorithms.

Though, recent versions of various LINUX flavors come with attractive and friendly graphical user interfaces, basically LINUX is a command based operating system. In LINUX, there lies a command for everything and these commands enable you to carry out actions on any files and directories stored on your computer. However, improper execution of these commands can result in complete or partial data loss from LINUX based systems. As, we all know, data loss is inevitable, it is better to be prepared with latest backup. However, if the backup is not there or due to some unresolvable reason, failed to restore the lost data, you are badly in need of any efficient Linux Data Recovery software.

Taking a real life problem into consideration, suppose, there are four users for a single account on a LINUX system. The user IDs for the users are dba2adm, dba2adm1, dba2adm2 and dba2adm3 respectively. If you want to drop the Net Search Extender instance of user dba2adm, using nxidrop command, it will remove the Net Search Extender instance of db2adm along with the content of home directories of all the other users with prefix dba2adm.

Prime causes behind data loss in the above condition:

Creation of multiple user IDs on a LINUX system that share a common prefix.

This common prefix is also an user ID.

The nxidrop command is applied to the user ID, which is the prefix for other IDs.

Resolution:

If we believe in precaution, then we should avoid using 'nxidrop' command for a LINUX based system, where there are multiple user IDs present with the same prefix and the prefix itself is an user ID. However, if the problem has already occurred, there is no possible solution with LINUX, that can get back your data. Hence, to recover the lost content inside home directories of other users, you need to use any LINUX data recovery utility.

Such LINUX Recovery tools have effective scanning methods to recover and restore the lost files, folders, directories with their original structure. These powerful recovery utilities come with interactive user interfaces that make them easy to use without any prior technical knowledge on the same.

Stellar Phoenix Linux Data Recovery is one of the reliable as yet efficient Linux file recovery software in the market. It is the advanced of all applications in it's category and compatible with Ext2, Ext3 file system based Linux volumes. This power packed Linux data recovery software gets installed on Windows (Vista, XP, 2003 and 2000) and you can recover your lost data from the LINUX based drive by connecting the LINUX drive as the slave.

Today, the Linux operating system has carved a niche of its own. It has got a dedicated category of users who will happily pay for it if it ever comes with a price tag. The Linux system is secure, reliable, fast, and does not require hardware/software drivers to install them on the system. Having said that, even such a robust operating system can face corruption. Corruption can occur due to various reasons such as power outages, corrupt file system, human errors, damaged operating system, etc. In such cases, you should try performing appropriate corrective measures to sort out the issue. However, if you are unable to do so then you should use a third-party Linux data recovery software to perform Linux recovery.

Consider a scenario wherein you are working on a Red Hat Linux system. Suddenly, there is a power outage and the system shuts down unexpectedly. When you try to switch on the system, you fail to do so.

Cause:The cause of this situation is that the Linux system has corrupted because of power outage.

Resolution:If the problem is because of having a faulty hardware like bad hard drive or memory chip, the file system check may not be sufficient to resolve this problem. This happens particularly when the file system is corrupted. In such cases, the Red Hat boot process will produce an error message and guide you into a shell so that you can perform the file system repair yourself.

When the recovery shell dismounts all the file systems to mount the root file system in a read-only mode, you can perform full checks on it. To do this, you should run the e2fsck utility on the corrupted file system that will be able to resolve all the inconsistencies. Exit the shell and restart the system. The system will function normally now.

However, if you still are unable to recover the system then you should use a third-party Linux data recovery software to do the needful. Such read-only tools are able to recover the data safely without overwriting the existing data.

Stellar Phoenix Linux Data Recovery is a Linux recovery software that enables you to recover data from the corrupted Linux systems. It is supported by various Linux distributions such as Red Hat, SUSE, Debian, Caldera, Mandrake, Sorcerer, TurboLinux, Slackware, Gentoo, etc. This Linux data recovery software is able to perform Ext2 Recovery, Ext3 recovery, and Ext4 recovery. In addition, it can recover data from FAT12, FAT16, FAT32 file systems as well. This Linux recovery software is compatible with Windows 7, Vista, Server 2003, XP, and 2000.

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.