Data Loss due to Inode Corruption

SCO UnixWare operating system is a Unix-based operating system that is primarily known for its reliability, stability and scalability. While the operating system is safe and reliable, it can also be corrupted and unmountable due to super block damage or corruption, inode corruption, boot errors, VTOC (Volume Tables of Contents) damage, OLT (Object Location Table) damage and malicious software like virus. In most cases of operating system corruption, you encounter an error message. Once you encounter the error message, the data stored in the hard drive becomes inaccessible. To overcome such situations, the best possible way is to restore the data from an up-to-date backup. However, in case of no backup availability or backup failing short of restoring the required data, you need to use advanced SCO UnixWare Data Recovery Software.

Consider a practical scenario, where you encounter the below error message when you attempt to boot your UNIX based operating system:

“Mar 15 17:26:21 ioccrmprep1 unix: WARNING: msgcnt 31 vxfs: mesg 017:

vx_ilock - /opt/data/ora16/preprod file system inode 10 marked bad”

The above error message indicates that inode 10 has been marked bad. Data saved in the hard drive becomes inaccessible after the above error message appears.

Cause:

The root cause for the occurrence of the above error message is VERITAS File System inode corruption as a result of transient fiber link failures.

Resolution:

To resolve the above error message and access the data, you need to take these steps:

1. Unmount the file system in order to attempt repairs on corrupted inodes. Use the command to analyze the superblock on the failing file system:

% echo "8192B.p S" | fsdb -F vxfs /dev/vx/rdsk/rootdg/meta

2. Run a full fsck with the -n option to see which inodes are marked bad

3. Set the "aflag" field to 0x0 using fsdb. This step must be done very crefully since it involves writing to the file system structure itself. The incorrect use of fsdb can destroy the file system.

4. The inode aflag has been cleared for the 3 inodes. Verify it with fsck.

5. Now it should be safe to run a full fsck with the -y option

6. Mount the file system and check the inodes

If the above steps fail to resolve the issue, you need to reinstall the file system. These file systems act as pointers to the files and folders saved on the hard drive. Reinstalling the file system will erase all those entries and your data will become inaccessible. In such circumstances, you need to go for an advanced SCO  UnixWare Data Recovery  Software. Such UnixWare Data Recovery tools use advanced scanning algorithms to recover your lost data.

Stellar Phoenix (SCO UnixWare) Data Recovery is powerful UnixWare Data Recovery utility. It is compatible with VxFS [Veritas File System - VxFS1, VxFS2 & VxFS4] and UFS File systems. It gets installed on Windows (XP, 2003, 2000, NT, ME, 98 and 95) and the affected SCO hard drive should be connected as slave.