Data loss after power loss and disk full

Question

Hello,

Our server recently experienced a power outage outage. Upon restarting confluence would not start. I had reviewed the startup logs and it said it was not able to start due to the disk being full.

I have removed some of the older daily backups and noticed that they seemed to have stopped a few months ago. After freeing up some space confluence started up but was missing a few months worth of data. From what I can tell it looks like we are using the HSQLDB database.

Is there anything that can be done to recover this data?

Thanks

Mike Gibbons · Answer

Thanks for the explanation Nic. When I saw it had been setup to use the HSQL database it certainly made me a little nervous. Are there any temp folders outside of the confluence home directory to check for data?

Nic Brough -Adaptavist- · Answer

There is a very good chance that you've lost it all.  I'm actually quite surprised you can start Confluence and find any data at all, as running out of disk space will truncate what goes into the HSQLDB database and usually make it unreadable at the end, which stops Confluence working.

I suspect things have appeared to carry on working because HSQL is read into memory and the memory used as the database until you shut down, when it writes.  A crash and reboot means no write, so you've recently been writing most changes into (volatile) memory instead of to the disk.  That explains why you've lost a chunk of data.

Your very last daily backup from before you lost the disk space is probably the only 100% certain backup.  What is currently running is likely to be ok, so you could also export that.

This is another good reason the admin sections warn you not to use HSQL.  I'd take one of the exports, and import it into Confluence with a proper database behind it.  And write off the data-loss, I can't think of a way to get that back.