Storage Server Data Disasters – Common Scenarios (Part II)

Possible causes of hardware related disasters:
•    Server hardware upgrades (storage controller firmware, BIOS, RAID firmware)
•    Expanding storage array capacity by adding larger drives to controller
•    Failed array controller
•    Failed drive on storage array
•    Multiple failed drives on storage array
•    Storage array failure but drives are working
•    Failed boot drive
•    Migration to new storage array system

Case study
Netware volume server, Traditional NWFS, failing hard drive made volume inaccessible; Netware would not mount volume. Errors on hard drive were not in the data area and drive was still functional. Copied all of the data to another volume; 100% recovery.
Evaluation time: 1 hour

Causes of software related disasters:
•    Business system software upgrades (service packs, patches to business system)
•    Anti-virus software deleted/truncated suspect file in error and data has been deleted, overwritten or both

Case study
Partial drive copy overwrite using third party tools, overwrite started and then crashed 1% into the process, found a large portion of the original data. Rebuilt file system, provided reports on recoverable data; customer will be requiring that we test some files to verify quality of recovery.
Evaluation time: 1 hour

Causes of user error disasters:
•    During a data loss disaster, restored backup data to exact location, thereby overwriting it
•    Deleted files
•    Overwritten operating system with reinstall of OS or application software

Case study
User’s machine had the OS reinstalled – restore CD was used; user looking for Outlook PST file. Searched for PST data through the drive because original file system completely overwritten. Found three potential files that might contain the user’s data, after using PST recovery tools we found one of those files to contain all of the user’s email; there were missing messages, majority of the messages/attachments came back.
Evaluation time: 5 hours

Causes of operating system related disasters:
•    Server OS upgrades (service packs, patches to OS)
•    Migration to different OS

Case study
Netware traditional, 2TB volume, damage to file system when trying to expand size of volume, repaired on drive, volume mountable. Evaluation time: 4 hours

When a data loss occurs on something as valuable as a server, it is essential to the life of your business to get back up and running as soon as possible.