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wgstarks

Is this disk bad?

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By failed, I assume you just mean disabled and have no idea whether the disk or something else is to blame. Have you tried checking connections? Other ports? Without a SMART report we can't say for sure if the disk has failed or not. If it is truly dead then of course you won't be able to get SMART, but if you haven't tried anything to see if it will respond then we don't know.

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Thanks. Tried stopping the array to see if I could reassign the disk, but it's not available to assign. I've got enough empty space to move all the emulated data to another disk. Probably do that and then try moving the disk to another slot and see what happens.

Edited by wgstarks

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If the disk has dropped off line, stopping the array won't make it reappear. Even a reboot might not restore communication with the controller as a power cycle is often needed. You need to shut down, check the SATA cable and power to the disk and power up again. Then see if you can get a SMART report.

 

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Of course the best thing is to have good backups so you aren't really that worried about losing data while you have a disk problem. Do you have good backups of any important and irreplaceable files?

 

2 hours ago, wgstarks said:

I've got enough empty space to move all the emulated data to another disk. Probably do that and then try moving the disk to another slot and see what happens.

 

That seems to be a common reaction to this situation, but I don't really recommend it. Since you don't have dual parity, your array is unprotected. In order to move data from the emulated disk to other disks in the array, your system will have to read all the other disks to calculate the missing data, then write the missing data to another disk, which will update parity, then delete the data from the emulated disk, which will update parity. So a lot of activity on an unprotected array that will make modifications to your parity.

 

If you do need to copy any of the emulated data, I recommend just copying it across the network to another computer if it isn't much data, or copying it to an Unassigned Device. That way you don't make any writes to an unprotected array and you don't alter parity.

 

If you insist on writing other disks in the array, just copy the data instead of moving it. At least that is one less set of writing/parity updates since nothing will be deleted from the emulated disk. And rebuild will still have that data just where it was to begin with.

 

But you should really just try to see if you can get the disk SMART by following John_M advice before doing anything else though.

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6 hours ago, John_M said:

If the disk has dropped off line, stopping the array won't make it reappear. Even a reboot might not restore communication with the controller as a power cycle is often needed. You need to shut down, check the SATA cable and power to the disk and power up again. Then see if you can get a SMART report.

 

You're right. Looks like it needed a power cycle to restore comms. Didn't see any visible problems with data and power cables. Sata cables are locking and didn't appear to be loose. No spare breakout cables to replace them with though.

 

I've reassigned the disk and data is currently rebuilding. SMART report is attached. Downloaded after completing a short test without any errors. I didn't see any issues in the report, but could easily have missed something. I've also got an extended test running but that'll take a while.

 

@trurl Thanks for the advice. Makes a lot of sense. And I do have multiple backups of anything important. This disk is almost entirely videos which I have on BD so could re-rip them if I had to. Just not much fun.🙂

 

brunnhilde-smart-20180828-2131.zip

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20 minutes ago, wgstarks said:

I've also got an extended test running but that'll take a while.

It will take a lot longer if you're running it at the same time as rebuilding the disk.

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21 hours ago, wgstarks said:

I've also got an extended test running but that'll take a while.

Extended SMART tests aren't really good friends with disk rebuilds.

 

Both the rebuild and the extended SMART test requires access to all of the disk surface.

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Disk looks OK. You can rebuild to a spare disk or rebuild to the same disk. If you rebuild to a spare disk, then you will have the original as a backup in case something goes wrong with the rebuild. But of course, that requires a spare disk.

 

While the disk is disabled, unRAID will emulate it from all the other disks with the parity calculation. You can of course read the emulated data. If it looks OK then it is probably fine to just rebuild to the same disk.

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1 hour ago, trurl said:

Did you determine why the disk dropped offline? Bad connection?

No. Checked the connections. None were loose. Cables are all "locking". The only thing I really know is that it dropped offline while another local computer was doing a read as part of a backup.

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