Parity upgrade instructions?

[mikeybunting]

Greetings all.  I ordered a couple of 3TB drives  today via NewEgg.  Are there instructions posted somewhere that will outline the step by step instructions that I will need to follow so that I can upgrade from 2TB parity to 3TB parity safely?

 

Many thanks for any/all help....

[itimpi]

I am not sure if there are detailed instructions (I expect there are in the wiki), but the steps are very simple:

• Run a parity check on your current drives - you do not want to do an upgrade of the parity drive if you have any issues with your data disks.  Also make sure that no data disks are red-balled..
  
• Stop the array and unassign the parity drive so the array is temporarily unprotected.
  
• Swap the old parity drive for the new one (this may involve stopping/starting your server if it does not support hot-swapping of drives.
  
• Put the old parity drive somewhere safe for a while (this is your protection against a data drive failing while doing the swap to the new parity drive).
  
• Assign the new parity drive.  Start the array to create parity on the new drive.
  
• In theory when this completes you are finished - but you might want to do a NOCORRECT parity check to confirm everything is OK. 
  
• At this point you can re-use your old parity drive as you will no longer need it as insurance as your array is once again protected.

 

 

[JonathanM]

I would add the initial step of backing up the contents of the flash drive before changing any drive assignments. That way you can put the old parity drive back in without jumping through a bunch of hoops if something goes wrong during the upgrade.

[flambot]

I'd like to ask a clarification question here - mainly because I will be doing this very soon myself.

 

Is the unassignment of the parity drive necessary?? It's been a long, long time since I changed mine, but all I remember doing is just swapping out the old one for the new one and unRAID realised the change and rebuilt parity. Still...my memory is flawed

[garycase]

Is the unassignment of the parity drive necessary?

 

It wasn't with v4.7, but I'm not sure about v5.    I know you do need to do it if the drive's been red-balled; but I don't think it's necessary if you simply swap the drives.    I'd just shut down; swap the drives; and restart and see if it automatically starts the rebuild.    If not, you can simply do the stop/unassign/start/stop/assign/start sequence then 

[garycase]

... by the way, I absolutely agree with jonathanm's suggestion to back up the flash drive before you start.

That provides a simple way to recover in the unlikely event that you have a data drive fail during the initial parity sync onto the new drive.

 

[RickInHouston]

I'd assume you should preclear the drive before you even stop the current array.?.

 

Also, why do you want a NONCORRECT / check the parity?  I just got my new array set up.  Ran parity and ran a correct and there were 0 errors.  I ran it to correct anything, if necessary.

[darkside40]

I am also want to upgrade my parity drive and i want to reuse my old parity drive as data drive.

 

I just have a question about that. Do i need to do the whole preclear process on the old parity drive again before using it in the array, or could i just add it to the array and it will work instantly?

[garycase]

Since the old parity drive has been rather well "tested" in daily use as a parity drive, you can skip the pre-read and post-read parts of the pre-clear cycle -- but it's still a good idea to use pre-clear to prep the disk, so it will only take a few minutes to add it to the array, instead of the many hours it would take to clear it.

 

Just use the -n option with the pre-clear command.

 

i.e. to pre-clear disk sdx, use:

 

preclear_disk.sh -n /dev/sdx

 

That will take about 1/4th as long as a full pre-clear cycle.

 

After you've added it to the array and formatted it, you should do a correcting parity check just to confirm all is well.

 

[darkside40]

Thanks garycase,

thats was what i really wanted to know.