Nasty CRC backup restore failure.Probably cPanel needs a feature to prevent this.

Avensen

Member
Feb 27, 2007
17
1
153
Hi everyone,

yesterday I needed to restore an account from a daily legacy backup, on a server which had "use pigz" option enabled during backup and during restore.

I terminated the account and ran legacy backup restore from WHM. And to my surprise, restoration failed with tar CRC error message. Tried again, failed again: unable to unpack archive. CRC error mesage. HDD had enough space.

I successfully restored the same account on the same box many times before, restoration never failed in past.

To test tar.gz archive in question, I copied it to a Windows machine, unpacked it with WinRar -- no errors found.
Then tested the archive on the server via shell by unpacking it with gunzip to dev/null - no errors found.

How is this possible? Is this preventable? Can we have a feature in cPanel that checks created .tar.gz archives after backup complete for integrity (for CRC errors)?

Also, some archive software, for example, WiinRar have a "recovery record" feature, description from Wikipedia:

Many archive formats contain redundant data embedded in the files in order to detect data storage or transmission errors, and the software used to read the archive files contain logic to detect and correct errors.
they can add extra bytes to archive to improve its "durability". Can we have a feature in cPanel that creates backup archives with extra recovery record?
 

cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,913
2,202
363
Hello :)

If the archive is extracted successfully using "tar" then it should still be salvageable. Could you open a support ticket using the link in my signature so we can review the archive and try to determine why it can't be used to restore the account? You can post the ticket number here so we can update this thread with the outcome.

Thank you.
 

Avensen

Member
Feb 27, 2007
17
1
153
Michael, already restored site from an earlier backup and deleted the archive in question, my fault. I'll open a ticket if this happens again. Sorry for the rant :)