Ok - here is the situation.  I want to replace a disk in my array - from 300G to 750G.  I want the 300G drive to stay in the unRAID box for the time being.  (It is an IDE drive and disconnecting it would be a pain).  What I want to do, is after the drive is replaced, to format the 300G and use it as a standalone networked drive.  I will be able to write to the drive at high speed - something I have a need for.  I understand it won't be protected which is fine for this disk.  I have some instructions in another thread on how to share a standalone disk on the unRAID box.

 

So here is the question, if I add the new disk and boot the box, my array will come up as before.  I can then stop the array, and take the 300g drive out of disk6, and put the 750G into disk6.  My question is ... will I then be able to start the array and have it rebuild the disk onto the 750G drive.  I though I remembered reading that you actually had to disconnect the old drive and then unRAID would automatically detect the new disk.  If I have to disconnect the old disk, I'd like to know now, before I put the 750G in the case.

 

Thanks for your help!

 

Brian

Someone else may correct me, but I think the simplest procedure would be to Stop the array and un-assign Disk 6, then Power down and install the 750GB, then boot up the server.  Because a drive is missing/un-assigned, the array should not automatically start.  Then assign Disk 6 to the 750GB and Start, and it should rebuild the Disk 6 contents on the new drive.  There's no need to physically disconnect anything.

 

That is exactly what I needed to know.  It is rebuilding the drive now.  Thank you!!!

Success!

 

It took about 11 hours - not too bad for 750G, reconstructing from 11 other data disks + parity.  unRAID could do this quicker if, after it hit the size of the disk it was replacing (300G in this case), it started writing binary zeros to the drive.  I'm pretty sure it would have the same effect and be a lot quicker.  (With all the feature requests out there I'm not adding this one right now.  What it does now works reliably and is quick enough for the infrequent need to replace a disk.)

 

-Brian

unRAID could do this quicker if, after it hit the size of the disk it was replacing (300G in this case), it started writing binary zeros to the drive. 

 

The reason it doesn't do this is because when you click Start, not only does it start the reconstruct, it also immediately expands the file system and exports the disk being reconstructed.  So while reconstruct is under way, you can start writing to the additional storage made available because the new disk is larger.  Hence when reconstruct process reaches beyond the size of the original disk, it can not just start writing zeros 

Makes sense!  (Although I'd be hesitant to write to a disk that is the middle of being rebuilt!)