hi there;

 

i plan to do an upgrade where 12 of 16 disk (no cache, but parity included) of my unraid server -used mainly for backups- will be replaced; i'll also update from 4.5.6 to 4.7 at this point... i'd be very thankful if anyone comments on how i will try to do this and if it will work the way i think:

 

1) stop existing array, unassign _every_ disk

2) update unraid to 4.7

2) build a complete new & empty array of 12 new disks plus the old (zeroed) parity disk

... i know, after zeroing my old parity disk, i'm at (minor) risk to lose data, but because most of the data are backups, it'll be no big problem

3) after the new array is ready, unassign the parity disk

4) mount old disks one by one, and directly copy the data via midnight commander to the new array (from within unraid)

... here i assume, that in step 1 unassigned disks are still accessible like normal disks from wihtin unraid - right?

5) because all of the existing data fits onto the new array, i'll be safe to zero 3 of the existing disks and assign them to the new array

6) reassign the parity disk, and let unraid create a new full parity set

... it'll do that automatically if the parity disk is reassigned - right?

7) DONE! 12 of 16 disks are replaced, storage expanded about 40%

7b) i'll keep 4 of the 12 old disks as extra "offline" backup, because they hold some (non critical) data which currently only exists on my unraid server

 

any misconception? thoughts? tipps?

thanks in advance...

 

 

hi there;

 

i plan to do an upgrade where 12 of 16 disk (no cache, but parity included) of my unraid server -used mainly for backups- will be replaced; i'll also update from 4.5.6 to 4.7 at this point... i'd be very thankful if anyone comments on how i will try to do this and if it will work the way i think:

 

1) stop existing array, unassign _every_ disk

2) update unraid to 4.7

2) build a complete new & empty array of 12 new disks plus the old (zeroed) parity disk

... i know, after zeroing my old parity disk, i'm at (minor) risk to lose data, but because most of the data are backups, it'll be no big problem

Ok so far.    I think.  To be certain the new disks will perform it is strongly recommended you use the preclear_disk.sh script on all of them before assigning them to your new array.  This can be done now before disassembly of the existing array configuration. 

3) after the new array is ready, unassign the parity disk

No  reason to assign it at all, not at first, not until just BEFORE you start zeroing the old disks with your data

4) mount old disks one by one, and directly copy the data via midnight commander to the new array (from within unraid)

... here i assume, that in step 1 unassigned disks are still accessible like normal disks from wihtin unraid - right?

They will be accessible ONLY with the use of add-ons not normally included in unRAID, or the equivalent command line commands.  (Either unMENU or SNAP will greatly assist).

5) because all of the existing data fits onto the new array, i'll be safe to zero 3 of the existing disks and assign them to the new array

It will NOT be safe until you both calculate parity on the new array AND then check parity on the new array.

6) reassign the parity disk, and let unraid create a new full parity set

... it'll do that automatically if the parity disk is reassigned - right?

Yes, but parity assignment/calculation/check really needs to be done before zeroing the old disks.  If you use the preclear script you can add the in a few minutes. 

7) DONE! 12 of 16 disks are replaced, storage expanded about 40%

7b) i'll keep 4 of the 12 old disks as extra "offline" backup, because they hold some (non critical) data which currently only exists on my unraid server

 

any misconception? thoughts? tipps?

thanks in advance...

Sounds like a plan... Just remember about 1 out of 5 drives has some issues lately that shows itself in the preclear-disk.sh burn-in process.  (I guess it depends on how many times it was dropped in the shipment to your address.)

 

There is a brand new preclear_disk.sh script that will give an easier to read final report.  Make sure you get the newest version.

hi Joe L. & thanks for your input.

i'll better not quote again, as this may get a bit confusing

 

some notes: i use unmenu and have already used the preclear script (and for shure will update it - thanks for the tip); i also copied data from ntfs disks to my unraid server when i first installed it - so i assume the process will be the same with disks, which where just unassigned from an unraid array.

 

even if lucky me had no single doa or early drop out failure with about 30 disks in the last 3 years (only 1 disks with some bad sectors at all, after 2yrs of 24/7), you made one important point here, because it is easy to understand why it is better to preclear/test new disks before changing anything.

 

another point, if i understand you right is, that i may use the new array without a parity drive assigned? didn't know that, but understand how the "shift" in the sequence makes it even more secure.

 

thanks again, this are some valuable tips.