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rgio

Cache Drive ++ Data Loss

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TL;DR-my cache drive failed and I lost a bunch of data.  I've basically given up hope on recovery, but I'd love to know how to prevent something similar in the future.

 

I did something stupid and lost a BUNCH of data.  Hopefully this serves as a record for the future.  I have a 5 drive array plus a cache drive (Toshiba OCZ 512GB).  I did some fairly sizeable transfers from my laptop to Share A (which uses the cache drive) and verified that they showed up correctly in AFP.

 

At some point a few days later, I attempted to stop the array.  It sat on "stopping the array" forever, so I did a hard reset.  Everything seemed fine the next couple of days.

 

Then one day, I try to look for a file, but it isn't there.  This is when I notice only a portion of the extent of the data loss, which is partial across multiple folders (no folders entirely, though).  And a weird abnormality--my server has renamed itself "Tower" and cleared all of the Identifications settings I had.  In my troubleshooting investigation, I discover the cache drive is unmountable.  Rather than try to troubleshoot it like a sane human, I just reformat and remount the drive. 

 

Past moronic me was certain that a cache drive would just "cache" data.  It would never (I thought) remove files from the array and store them only on the cache drive.  I think I went wrong by setting this share to "prefer" the cache drive instead of just using it.  So the data was stored only on the cache drive and was nuked when I nuked the cache drive.  

 

Some clarification on how to configure cache drives properly would be great in the comments (after the mandatory laughter and moment of silence for my years of now-dead files).

 

Thanks, all.

 

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Turn on the help on the share configuration page and read the descriptions of the various cache settings.

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Also, you must have a backup plan. unRAID parity can't save you from everything, as you have seen. You don't have to backup everything, but you absolutely must have a backup of any important and irreplaceable files.

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And another thing.

 

It's quite possible files could have been recovered by repairing the filesystem on the cache drive. You should have asked before doing anything. Please ask the forum in the future.

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