Installing 2x nvme drives for caches

[asw2012]

I will be installing a nvme 512GB cache drive on each pool in my TrueNas server. This in hopes of speeding things up a bit.

Please let me know how to best check read/write speeds before and after installing them. What command line should I use, or are there other methods? I would like to see any performance gains.

Thanks.

 

[Jailer]

I will be installing a nvme 512GB cache drive on each pool in my TrueNas server. This in hopes of speeding things up a bit.

What exactly are you trying to speed up?

 

[jgreco]

I will be installing a nvme 512GB cache drive on each pool in my TrueNas server. This in hopes of speeding things up a bit.

Please let me know how to best check read/write speeds before and after installing them. What command line should I use, or are there other methods? I would like to see any performance gains.

Thanks.

How much system memory are you planning to add to go along with this?

As it stands, with 32GB, I would expect your performance to suffer quite a bit from the status quo.

With 64GB, you might or might not see modest improvements for certain workloads, but you are still so far over the maximum 10:1 L2ARC:ARC ratio that it's really hard to say.

With 128GB or 256GB of RAM, you should see some improvement. There isn't a "command line" way to test this; that implies a benchmark, and benchmarks are notoriously useless against ZFS. What you do is you take your filer, monitor its stats before, when it is good and "warmed up" for a week or four, see what the ARC stats look like, then you add your L2ARC, and see if and how pool accesses decrease.

 

[asw2012]

What exactly are you trying to speed up?

Right now I'm suffering from what I am thinking read speeds. This box has emby, subsonic and now just added nextcloud. When using all three, I get stutters in emby and it takes sometimes up to 12-15 seconds to load nextcloud from within and externally.

 

[asw2012]

How much system memory are you planning to add to go along with this?

As it stands, with 32GB, I would expect your performance to suffer quite a bit from the status quo.

With 64GB, you might or might not see modest improvements for certain workloads, but you are still so far over the maximum 10:1 L2ARC:ARC ratio that it's really hard to say.

With 128GB or 256GB of RAM, you should see some improvement. There isn't a "command line" way to test this; that implies a benchmark, and benchmarks are notoriously useless against ZFS. What you do is you take your filer, monitor its stats before, when it is good and "warmed up" for a week or four, see what the ARC stats look like, then you add your L2ARC, and see if and how pool accesses decrease.

Unfortunately, this mobo supports max 32GB memory. It's starting to look like an upgrade is in store, as I keep adding to what this original NAS box intended use. I've noticed a big slowdown after I installed nextcloud.

But I will first take note of the ARC stats, after I've used the box a few weeks to load up the files.