SSD choice for VM pool

[teapot9]

Hello,

I have a CSE-846 server with 24GB RAM.
I plan to have a 7x8TB HDD raidz2 vdev in a main pool, but I am thinking about getting 3x1TB or 3x2TB SSDs raidz1 for a dedicated VM pool.
VM workload is media sharing/streaming/transcoding, file hosting, backup services, desktop VMs.
All of the servers should not be used by more than 3 people simultaneously, 1 on average.

I will probably buy an LSI 9211 or 9207 controller with a SAS expander for my SAS HDDs.
I have several questions reguarding ZFS, SSD ans SAS controllers:

1. Should I connect the SSDs to the SAS controller or the on-board SATA controller?
I have read that some SAS controller had issues with TRIM support.

2. Are consummer SSDs ok with ZFS?
I also found threads about some SSDs having issue with ZFS for trim.

3. Is trim something I should worry about for a VM oriented pool?

Thank you.

 

[Forza]

I suppose go with high end SSDs with high TBW and 5 year warranty. Don't do cheap ones. I've heard several cases of kingston and sandisk return corrupt data after some time of use.

 

[teapot9]

What is considered a high TBW?
For 1TB SATA SSDs, I found TBW from 300 to 400TB.
I did notice NVME SSDs have way higher TBW but they take up PCIe lanes, which will be an issue if I want to add another vdev in the future.

 

[Forza]

Look for 5 year warranty. Avoid QLC.

Seagate Ironwolf 1TB has 1400TBW and 5 years warranty. It's an TLC based flash drive.
Samsung 860Pro 1TB has 1200TBW and 5 years warranty. Its an MLC based flash drive.
WD SA500 1TB has 600TBW and 5 years warranty. Not sure if it is MLC or TLC.

 

[teapot9]

Looks like Amazon is listing wrong warranty.
Samsung 860 pro for instance has 2 years manufacturer warrantyon Amazon, while on Samsung's website it is listed with 5 years.
I will refer to the manufacturer website for warranty in the future.

Thanks for the information

 

[QonoS]

1. Should I connect the SSDs to the SAS controller or the on-board SATA controller?
I did not read about that but anyhow nothing speaks against on-board SATA controller.

2. Are consummer SSDs ok with ZFS?
Most consumer SSDs are not suitable for a VM oriented pool. Of course this heavily depends on the actual loads but generally speaking enterprise SSDs are clearly the better choice. Enterprise SSD come with higher TBW and are optimized for the targeted workload. Although Chia dried the market up there is still some relatively cheap, used enterprise SSD available that often has 90% or more lifetime left. If you are looking for something cost-effective. ;)

3. Is trim something I should worry about for a VM oriented pool?
Yes, using TRIM will prolong SSD lifetime and keep performance up over time. Depending on actual workload you can even think about overprovisioning SSDs.

 

[NugentS]

I use Crucial MX SSD's at the moment and estimate that I should get 4-5 years from them (about) before they wear out. I used a previous set of MX's on a QNAP NAS and in they lasted well. I expect that TrueNAS will be harder on the new drives