I just finished up the 31 hour pre-clear process, brought my array down and added the disk then brought the array up to remember I hadnt formatted the disk yet.  I then stopped the array, removed the disk and restarted it so that I could format the disk.  At that point Unraid started complaining about data integrity because I pulled the non-formatted disk from the array.  After the format I restopped the array, added the disk and started the array.  Now its rebuilding the pre-cleared disk's contents an will be doing it for the next 12 hours.  Is there a reason why Unraid allows unformatted disks to be added to the array?

Is there a reason why Unraid allows unformatted disks to be added to the array?

 

You can only add an unformatted (or cleared) disk, formatting is done after it was added to the array.

Weird since I dont think I could format it while it was in the array and did it when it wasnt part of the array.  Im not worried about its data getting corrupted since it had none.

Weird since I dont think I could format it while it was in the array and did it when it wasnt part of the array.  Im not worried about its data getting corrupted since it had none.

Nothing weird about it and you must be mistaken about the details of what you did or about how to do it.

 

You can't add a formatted disk to the array without invalidating parity. A formatted disk does have data. It has the metadata for the filesystem. Formatting a disk has always meant "write an empty filesystem to this disk" on every operating system you have ever used.

 

Since only a clear disk has no impact on parity, unRAID will clear a disk when you add it to a parity array unless you preclear it first. And since you formatted it, it was no longer clear.

 

Preclearing the disk so unRAID doesn't have to, then adding it to the array, then letting unRAID format it is the correct procedure.

 

It's unclear what state everything is in now. Is it rebuilding the disk, or is it clearing it? If it is rebuilding it, is it rebuilding it with a valid filesystem?

 

Parity is probably correct whatever state the data disk is in. After it is finished, if unRAID says the disk is unformatted then let it format it while it is in the array. This is probably the simplest outcome. If it thinks it is already formatted then I would recommend checking the filesystem just to make sure it is OK.

 

And any time I make a change to the array I always do a final parity check after everything else.

Actually, probably the simplest and quickest way to make sure the disk is formatted correctly with a valid filesystem is just to make unRAID format it again. To do this you would have to stop the array, go to the disk's page and change its filesystem, then change it back.

 

The only thing I'm not sure about is whether you would have to start the array and let it format to the changed filesystem before changing it back and starting the array and letting it format to the filesystem you want.

 

Maybe johnnie knows. He has tried to break unRAID a lot more than most of us it seems.

 

In any case, formatting is fairly quick since all it is doing is writing a small amount of filesystem data, basically what is required to represent an empty top level directory.

 

I know some of this may seem complicated but if you understand how parity in general works, and the fact that unRAID parity is realtime, and the fact that a formatted disk has data on it that affects parity, then all of these other details are pretty obvious.

If I understood him correctly he formatted the disk outside the array after starting it with the disk missing, if so unRAID is now rebuild the missing as it was before the format, so it should show unmountable and it has to be formatted after or during the rebuild.

If I understood him correctly he formatted the disk outside the array after starting it with the disk missing, if so unRAID is now rebuild the missing as it was before the format, so it should show unmountable and it has to be formatted after or during the rebuild.

OK, I guess that sort of makes sense. So it is rebuilding it back to the precleared state.

I ended up deciding to start over.  I stopped the array, pulled the new disk, shut unraid down, disconnected the disk, started it back up and ran "New Config" then assigned the old disks back into their old positions and am now running the parity check which has unfortunately found 18 errors for some reason in the first 17%.  Once that is done I will shut it down again, reconnect the new disk then rerun preclear on it.  Oh well, its not like I had anything better to do with the extra space right now.

I guess I really should have read the directions before starting this whole thing.  Second time did it, thanks all.

One suggestion would be to remove the ability to format a disk when the array is not running.  I still dont know how I missed the option while the array was running but the Unraid gui allowed me to format it while the disk was outside the array.  PEBKAC.

One suggestion would be to remove the ability to format a disk when the array is not running.  I still dont know how I missed the option while the array was running but the Unraid gui allowed me to format it while the disk was outside the array.  PEBKAC.

 

Are you sure it was unRAID and not some plugin?

One suggestion would be to remove the ability to format a disk when the array is not running.  I still dont know how I missed the option while the array was running but the Unraid gui allowed me to format it while the disk was outside the array.  PEBKAC.

 

Are you sure it was unRAID and not some plugin?

Must have been Unassigned Devices unless he did it at the command line. I'm pretty sure there is no way in the GUI to mount a disk and format it without starting the array. unRAID itself will not write to any disk that is not assigned, and it will not write to the assigned disks unless the array is started.

I ended up deciding to start over.  I stopped the array, pulled the new disk, shut unraid down, disconnected the disk, started it back up and ran "New Config" then assigned the old disks back into their old positions and am now running the parity check which has unfortunately found 18 errors for some reason in the first 17%.  Once that is done I will shut it down again, reconnect the new disk then rerun preclear on it.  Oh well, its not like I had anything better to do with the extra space right now.

 

Actually, what you should have done was simply do a New Config INCLUDING the new disk; then just let the system run a parity sync.    This would have eliminated the need to clear the new disk.    When the parity sync completed, you could simply format the new disk (a very quick process ... 2-3 minutes) and you'd have been good to go.

 

I assume since you indicated you're doing a CHECK and not a SYNC, and that you've seen errors, that those errors are due to the process you just went though.  As long as it's a correcting check everything will be sorted out when it completes ... and you can then add the new disk again (which you should pre-clear first so UnRAID won't have to clear it).