Best Use of an SSD to Enhance Performance

[tbutler]

I have an old HP N40L MicroServer running FreeNAS 11.3 which I'm planning on upgrading to TrueNAS 12 soon. It has a 4 drive RAIDZ array setup for storing mostly videos, photos and system backups on the server's storage pool. It is connected to my computer via GigE.

I'd like to add a spare 1 TB SATA SSD that I have at my disposal as a means to somehow boost the performance. I'd thought about a cache for the RAIDZ pool, but it seems like there is a lot of material online suggesting I'll be disappointed at the performance gains of doing so. I'm intrigued by the new addition of support to offload metadata and small files to an SSD in TrueNAS 12, but I'm hesitant to go that route since the N40L has only one remaining SATA connector, which means there would be no redundancy for said SSD.

Given these caveats, is there a way to take the equipment I have available to optimize ZFS performance or should I just use the SSD as a separate drive?

 

[SweetAndLow]

I have an old HP N40L MicroServer running FreeNAS 11.3 which I'm planning on upgrading to TrueNAS 12 soon. It has a 4 drive RAIDZ array setup for storing mostly videos, photos and system backups on the server's storage pool. It is connected to my computer via GigE.

I'd like to add a spare 1 TB SATA SSD that I have at my disposal as a means to somehow boost the performance. I'd thought about a cache for the RAIDZ pool, but it seems like there is a lot of material online suggesting I'll be disappointed at the performance gains of doing so. I'm intrigued by the new addition of support to offload metadata and small files to an SSD in TrueNAS 12, but I'm hesitant to go that route since the N40L has only one remaining SATA connector, which means there would be no redundancy for said SSD.

Given these caveats, is there a way to take the equipment I have available to optimize ZFS performance or should I just use the SSD as a separate drive?

Use it as a separate pool.

All the other options won't help much. And the meta data vdev should have the same amount of possibly drive failure as the other vdevs in the pool. So in your case with raidZ you would need a single mirror vdev.

 

[tbutler]

So when you say "use it as a separate pool," are you meaning as a pool that then would be the metadata vdev? Or just for other storage?

If my SATA SSD can't fit the bill (since I only have capacity for one more SATA drive), I'm contemplating getting a PCIe to dual M2 card (or a PCIe SATA controller) so that I could have a mirrored metadata vdev. Is it worth the cost for what I'd gain performance wise?

Assuming the metadata and small files don't need anywhere near 1TB, is it possible to use that mirrored device to do other things too? Or is it that whatever I set as the metadata vdev is dedicated entirely to that project?

 

[SweetAndLow]

So when you say "use it as a separate pool," are you meaning as a pool that then would be the metadata vdev? Or just for other storage?

If my SATA SSD can't fit the bill (since I only have capacity for one more SATA drive), I'm contemplating getting a PCIe to dual M2 card (or a PCIe SATA controller) so that I could have a mirrored metadata vdev. Is it worth the cost for what I'd gain performance wise?

Assuming the metadata and small files don't need anywhere near 1TB, is it possible to use that mirrored device to do other things too? Or is it that whatever I set as the metadata vdev is dedicated entirely to that project?

For your workflow no it doesn't make sense. Start simple and after you learn what you need then you can add it.

 

[tbutler]

Thanks. I’ve actually had the server going for years — since FreeNAS 9.x, at least — so in a sense I know what I’d like (for it to be faster, naturally!), I’ve just been trying to figure out if there is a way to push it further. It sounds like you’d say that’s a “no.” Which, I suppose, makes sense — an HDD ought to be able to saturate a GigE connection without the help of an SSD…

 

[SweetAndLow]

Thanks. I’ve actually had the server going for years — since FreeNAS 9.x, at least — so in a sense I know what I’d like (for it to be faster, naturally!), I’ve just been trying to figure out if there is a way to push it further. It sounds like you’d say that’s a “no.” Which, I suppose, makes sense — an HDD ought to be able to saturate a GigE connection without the help of an SSD…

What would you like to go faster? Streaming workflows, small file, high iops, ect.. so many things when it comes to performance. Most people just want their gigabit connection to max out. This is easy with a single disk.