Unreadable Sectors Moved To Different Drive

[preludeofme]

I'm fairly new to freenas and servers, but i've got a general knowledge, but i've got a weird issue that i'm not sure the best way to fix.

so i've been getting alerts about unreadable sectors on ada1, i ordered a new hard drive and just before it got here i got the alert that there was drive degradation. So i followed the steps on the documentation to replace the disk. I swapped the disks and got the server back online and resilvered.

now i'm getting the same error except this time it's on ada2, same number of unreadable sectors. Did i swap out the wrong drive or is there an issue with the data? I thought swapping out the drive would have resolved the bad sectors. any thoughts on next steps for this? let me know what info to post to help

 

[Samuel Tai]

Did you check the serial numbers of the drives before you swapped? FreeNAS doesn't always keep drive identifiers constant. You could very well have swapped the wrong drive.

 

[preludeofme]

i took a screenshot of the drives and serial numbers, and thought i grabbed the right one. so you're saying that ada1 could have changed to ada2 when i swapped it out?

ada1 was showing as degraded before i swapped it, and after i swapped it there were no degraded drives so i thought i got the right one. What would happen if i swapped the new one back out for the old one?

 

[Samuel Tai]

ada1 could have changed to ada2 when i swapped it out?

Yes. For example, when I swapped a drive, the old drive was ada2, but the new drive appeared as ada5. Everything went back to their original locations after a reboot. So long as you verified the serial numbers before and after, you should've swapped the correct drive. In your case, a second drive may be going bad, if they came from the same manufacturing batch.

 

[pschatz100]

Also, check to make certain all the cables are securely plugged in. It is possible that a cable might have been knocked loose.

 

[Ericloewe]

FreeNAS doesn't always keep drive identifiers constant

While I don't wish to detract from the overall message, FreeBSD enumerates devices in a fixed order. If there were no hardware changes, the IDs should not change.