Unraid Upgrades: New Parity, New Array Drive, Replace Cache

[ju_media]

I was hoping to gain some clarity from the community on the best way (if there is one) to go about the following upgrades to my unraid server. 
 

I’m very low on space so have picked up 2x new 16TB Toshiba enterprise drives, and plan to configure one as a new, 2nd parity drive. 
 

The other drive will be used to expand the array. So far I’ve run the ‘unassigned devices preclear’ on one of the drives, completing with no errors in around ~65 hours, and the second one is running now. I know this doesn’t need to be done for a new drive in the array, but wanted to stress test the drive regardless. 
 

I also need to replace my existing cache as it’s just not large enough any more to handle the kind of writes I’m doing on a daily basis; went with a Samsung 980 Pro 2TB after doing a fair bit of research on sustained write speeds of the various NVMe drives on the market. Couldn’t justify the bump in price to the Sabrent Rocket Plus 4 (?) 4TB variant. 
 

Is there a specific way I should go about doing these upgrades? I.e. add the new parity first, then add the new storage drive to the array, then replace the cache? (I’m not sure what is involved with fully replacing a cache drive, at this stage). 
 

There is quite a lot that lives on the cache currently; appdata, downloads, a few VM images, etc. 

 

Any guidance or insight much appreciated 🙂

[mathomas3]

From my experience, disable docker and envoke the mover which should move everything that is not currently being accessed...

 

in short... disable everything that would have access to the cache drive to include vms if that's where you have them running from and then envoke mover

 

I learned this the hard way when I moved somethings around in my system... but that's the way I would go about it

[trurl]

1 hour ago, ju_media said:

2x new 16TB Toshiba enterprise drives, and plan to configure one as a new, 2nd parity drive. 
 

The other drive will be used to expand the array

Is parity already 16TB or larger?

[ju_media]

2 hours ago, trurl said:

Is parity already 16TB or larger?

Yes, existing parity drive it 16TB. I wanted to go with 18TB drives for these 2 new ones, but then I remembered I wouldn't get ‘full use’ of 4TB of those. Also rebuild time would probably be horrendous. 

[ju_media]

3 hours ago, mathomas3 said:

From my experience, disable docker and envoke the mover which should move everything that is not currently being accessed...

 

in short... disable everything that would have access to the cache drive to include vms if that's where you have them running from and then envoke mover

 

I learned this the hard way when I moved somethings around in my system... but that's the way I would go about it

Nice one, thank you - so I guess that would include setting all shares to be ‘Cache: No’ ? And then invoke the mover so anything currently on ‘Cache: Yes/Prefer’ gets moved to the array? 
 

not sure of best practise for this with VMs and app data folders, I guess they can be moved to the array temporarily while I swap the cache drive. 

[trurl]

Nothing can move open files. Stopping individual VMs and Dockers isn't enough. You have to disable Docker and VM Manager in Settings.

 

Cache:prefer gets move From array To cache. Cache:yes gets moved from cache to array

[mathomas3]

long story shot... move EVERYTHING off the cache drive/s after that is done... remove the drive and start the array... stop it once more... add the new cache drive and start it...

[ju_media]

OK - I’ll be sure to do that when replacing the cache - thanks for the tips! 
 

For adding the 2nd parity vs adding the new storage drive, is there any difference if I do one before the other? I.e. down time, rebuild time, etc…

[itimpi]

54 minutes ago, ju_media said:

For adding the 2nd parity vs adding the new storage drive, is there any difference if I do one before the other? I.e. down time, rebuild time, etc…

Elapsed time should be the same (you cannot do both at once).  The only difference might be around safety - having a second parity to protect against 2 simultaneous disks having issues vs rebuilding a possible problem data drive.

[ju_media]

1 hour ago, itimpi said:

The only difference might be around safety - having a second parity to protect against 2 simultaneous disks having issues

Oh that’s a good point, so if I’ve understood correctly, I should add the new parity drive first, so I then have increased protection in the event that I face any drive issues during the ‘add a new storage drive’ stage.

[mathomas3]

sound advice