Help with drive settings?

[Star_weaver]

Wasn't sure what to use as the title but anyway

I have 8 drives

1x 240GB ssd - cache

1x 600 GB sas - parity

2x 600 GB sas - main storage

4x 148 GB sas - main storage

Is it safe to give 1 vm a 1TB drive or will that break things?

Is it worth me using the cache drive due to its size - want it to be more of a drive things get dumped onto when downloading or transferring stuff then pushed to main storage?

Any tips I should know about with the cache system?

[trurl]

Each data disk in the parity array is an independent filesystem, so no individual file can span disks. Unraid user shares allow folders to span disks, but files cannot.

 

Why are you using such small disks anyway?

[FreeMan]

1 hour ago, Star_weaver said:

Is it worth me using the cache drive due to its size

Until about 6 months ago, I ran my server first with a 250GB spinning cache drive, then a 240GB SDD. It housed all the dockers as well as serving as a cache. I've since upgraded by adding 2 more 240GB SDDs to the cache pool. I've grown my server from 2 1TB drives to the current 52TB all with one of these 3 cache configs, but almost all of it was with a single 240GB cache drive.

 

I'd venture to say that since your drives are positively tiny (by modern standards), your 240GB cache will be more than sufficient.

 

1 hour ago, Star_weaver said:

want it to be more of a drive things get dumped onto when downloading or transferring stuff then pushed to main storage?

That's the primary purpose of "cache".  Using it as a home for the docker.img file is another common (and recommended) use.

Edited September 4, 2020 by FreeMan

[Star_weaver]

4 hours ago, trurl said:

Each data disk in the parity array is an independent filesystem, so no individual file can span disks. Unraid user shares allow folders to span disks, but files cannot.

 

Why are you using such small disks anyway?

Mainly due to the fact that I don't have the option for 3.5 inch drives and I'm not going back to using 2.5 inch data drives again

[trurl]

8 minutes ago, Star_weaver said:

Mainly due to the fact that I don't have the option for 3.5 inch drives and I'm not going back to using 2.5 inch data drives again

What size are these disks if not 3.5 or 2.5?

[Star_weaver]

3 hours ago, FreeMan said:

Until about 6 months ago, I ran my server first with a 250GB spinning cache drive, then a 240GB SDD. It housed all the dockers as well as serving as a cache. I've since upgraded by adding 2 more 240GB SDDs to the cache pool. I've grown my server from 2 1TB drives to the current 52TB all with one of these 3 cache configs, but almost all of it was with a single 240GB cache drive.

 

I'd venture to say that since your drives are positively tiny (by modern standards), your 240GB cache will be more than sufficient.

 

That's the primary purpose of "cache".  Using it as a home for the docker.img file is another common (and recommended) use.

I'm gonna go with the screw cache option, filled up, paused all my vms, mover wouldn't clear cache after I set the shares to "yes" on the cache option, waited 3 hours after letting us mover work and it put everything into read only so I couldn't start any vm 

 

3 minutes ago, trurl said:

What size are these disks if not 3.5 or 2.5?

Auto correct strikes again, ment sata not data

[trurl]

1 hour ago, Star_weaver said:

I'm gonna go with the screw cache option, filled up, paused all my vms, mover wouldn't clear cache after I set the shares to "yes" on the cache option, waited 3 hours after letting us mover work and it put everything into read only so I couldn't start any vm 

Cache is a good place for the shares used by dockers/VMs, (appdata, domains, system). If these are on the array performance will be impacted by slower parity updates, and array disks will be kept spinning since there will be open files.

 

If anything, only use cache for this purpose. But really you have plenty of cache. You just need to figure out how to use it. We can help you work through all that.

[FreeMan]

18 hours ago, Star_weaver said:

I'm gonna go with the screw cache option, filled up, paused all my vms, mover wouldn't clear cache after I set the shares to "yes" on the cache option, waited 3 hours after letting us mover work and it put everything into read only so I couldn't start any vm 

If you've got 1 or 2TB of data to move over to the server all at once, you'll definitely blow out the cache and run into issues like this. Set your shares to not use cache while you're doing the initial population of data. At this point where you're doing a massive fill, all your drives will be spinning as you write directly to the array and it calculates parity for you.

 

After you've got the initial transfer done, you may chose to enable cache on one or more shares, as it makes sense for you. If you're writing 100GB or less per day to the server (you'll be doing significantly less if you're just saving pictures and Word docs, etc to it), the cache makes sense because you'll write basically at the speed you can transfer data and write to a fast SSD. Writing to the array, which is slower, will then occur nightly as it transfers data from the SSD cache to the spinners in the array. Again, though, this is entirely up to you.