Hey Guys-

 

Coming to unraid from the synology ecosystem.  Using Unraid as my plex server and housing my movies/tv files which are mostly mkv files.  I ran an rsync transfer between my synology nas and unraid to get everything over to my new rig.  

 

When trying to add a couple more hard drives, I Had a bit of a run-in w/udma crc errors due to a pci sas/sata card that didn't have updated firmware:  

 

In short, I had a bunch of udma errors, then a bunch of sync errors on parity check, and 1 of my 3 data disks was disabled.  After updating the firmware of my pci card, I stopped getting the udma errors, re-added the disabled disk, and just finished a parity check w/zero sync errors.  Hooray!

 

My question is:  Should I run rsync again between the synology nas and my unraid server?  If the parity check showed zero sync errors, does that mean my data is not corrupted? 

 

Thanks in advance.  

 

 

11 minutes ago, omartian said:

 If the parity check showed zero sync errors, does that mean my data is not corrupted? 

Not necessarily.  All zero errors means is that the parity calculation accurately represents the sum of all the bits in that location on all the drives.  If the source data on one or more drives is corrupt, the parity calculation will reflect the data in its corrupt state, but, the parity calculation is still "correct."

 

You may want to spot check some data on your unRAID server to see if there is any reason to believe some of the data may be corrupt.

33 minutes ago, Hoopster said:

Not necessarily.  All zero errors means is that the parity calculation accurately represents the sum of all the bits in that location on all the drives.  If the source data on one or more drives is corrupt, the parity calculation will reflect the data in its corrupt state, but, the parity calculation is still "correct."

 

You may want to spot check some data on your unRAID server to see if there is any reason to believe some of the data may be corrupt.

If the disk that was rebuilt from the parity drive, wouldn't it be identical to the pre-pci card issue?

A disk is not rebuilt from just the parity drive. The disk is rebuilt from the parity drive and all other non-failed disks. Parity alone is not enough to rebuild a drive.


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