Upgrading parity with minimal downtime

[jfeeser]

Hi all, i'm getting ready to do some upgrades to my array (thanks best buy for putting easystores on sale!), and as part of this i need to upgrade my parity drive to accomodate the new drive size.  I'd like to do this with the least amount of downtime as possible, as both my wife and i use the array for our businesses.  Is this procedure i found on reddit still the best one for that, seeing as i have open bays on my server?

 

1) Stop the array

2) Put the new drive into the server

3) Assign the new drive as "parity 2"

4) Start the array, allow parity to build on Parity 2

5) Once parity build is complete, stop the array

6) Remove old parity drive

7) Unassign Parity 1 in the array.

8 Start Array

 

Will this procedure still work?  I'd rather do a "hot" build of another parity than have my array down for an entire day while building a new parity (not to mention it's a ~50tb array so flying without a net for that long makes me nervous!)

 

Also, more of an OCD question, but once the new parity is built and the old parity is removed, can i reassign parity 2 to be parity 1?  Having a parity 2 and no parity 1 would probably cause my OCD to flare up

 

Thanks in advance!

 

[Squid]

15 minutes ago, jfeeser said:

can i reassign parity 2 to be parity 1? 

No.  The calculations are different for each parity drive.

 

BTW, the system is never "down" when rebuilding any particular drive.  You can still access it normally.  I do however try and limit access to the drives.  IE: I tend to do things like this during off hours.

[jfeeser]

Fair enough, i'll just have to tell my OCD to shut up.  Either that or do the same thing with _another_ drive to get a new valid parity 1.  

 

Good to know about the no-downtime during the rebuild, i could've sworn i read somewhere that data drives could be rebuilt with the array active but parity drives couldn't.  Happy to know i'm wrong about that one!  I'll probably still go with the "two parity" method just to keep having a valid existing parity while the new one builds.  Thanks for the ultra-fast response!

 

(off to start a new thread about some docker issues i'm having...see you there!)

[Squid]

17 minutes ago, jfeeser said:

i could've sworn i read somewhere that data drives could be rebuilt with the array active but parity drives couldn't. 

What you're probably thinking about is that an eon or so ago during the ice age of unRaid, you couldn't add a drive to an existing array without the entire array being down.