Intel M10 as Zlog in low end file server

[elag]

Hi
I am looking to upgrade my file server a bit. It now has a E3-1200v2. I am looking to upgrade to a Ryzen 5 3600 or Ryzen 7 3700X. I would like to use sync=always to improve data consistency. Most if not all access is using NFS anyhow.

On the motherboard I am looking at (Asrock Rack X470D4U) I have the option for 2 NVME disks: my other disks will be SATA. Intel Optane m10 32GB seems a reasonable option price wise for a NVME disk

So my question: Would it make sense to use a 32GB optane for Zlog? I know that size is not a problem: even with 10Gb link it should be plenty. Now one of the NVME drives will be on a PCIE2 slot, giving me about 1GB/sec. This is theoretically just below the 1.25GB that would be the maximum if the whole 10Gb link would be writes, which is pretty unlikely, so I assume that I can ignore that deficiency

PLP is not required for Optane, I understand, so for my low usage this setup should be fine, or did I miss something?

 

[T_Minus]

What and how many are your SATA disks?
Do you plan to use the SLOG device for that pool?
What pool configuration? (mirrors, rz2, etc)

You're not going to suddenly get 1Gbyte transfer with new NICs, there's many threads of people setting that as their goal too.

 

[gea]

Intel guarantees powerloss protection only for the datacenter Optane model 4800x although the risk on the desktop models seems low.

I have made some tests with the 32G Optane. Sync performance is way below the upperclass models up from 800P, more near a good Sata SSD. I have had also a lot of problems with it (not working in any configuration/OS). see https://napp-it.org/doc/downloads/optane_slog_pool_performane.pdf

If you can afford, start with the 800p-58.
If this is not for home use, buy the datacenter model 4801X-100 GB with guaranteed powerloss protection.

 

[elag]

Current configuration (I thought that I included it, sorry for missing it):
- 1 pool, 6 * WD RED 3TB in RAIDZ2, roughly 4 TB total allocated. These disks will in the future be replaced by some SATA SSDs or a mixture of SSD and SATA, each in their own pool
- currently the pool has a mirrored ZLOG on 2 SATA SSDs, shared with the OS-space. Right now after some 4 years I have written only 38TB to those SSDs. So write usage on the pool is low, hence endurance is not an issue.
- Currently there is also a FreeBSD system pool on the SSDs, but that does not need a ZLOG, so we can keep that out of the picture. I might even replace FreeBSD with something else (ZOL?) and even remove that pool
- Current the file server has 16GB of memory, pretty much everything is used for the ARC cache. On the new system I am planning to allocate 32GB for the ARC and the remaining 32G for some VMs

I am not worried about the 1GB speeds as I know that the pool is much slower and will limit the speed anyhow.
Large sequential transfers will occur seldomly. I am mainly interested in NFS responsiveness and latency, as I have my home directory on NFS+ZFS.
And B.T.W. I already have 10G connectivity right now. What I have now gets me into the 250MB range read speed and that is enough for me. I am only interested in a bit more snappyness over NFS

 

[zack$]

Sync writes and raidz2 are gonna have significant impacts on performance.

Seeing that data intergity seems to be a high priority for you, you should consider a PLP enabled drive for slog.

In your case a P3700 seems a good option can be had reasonably, which can be aic or u.2 to m.2 converted.

If you don't mind spending more, I agree with @gea that the p4801x (100gb) is an obvious choice. See: https://www.servethehome.com/intel-optane-dc-p4801x-review-100gb-m-2-nvme-ssd-log-option/

Also, with bifurcation supported on your, x16 you also have the option of going 4x nvme at full speed in either m.2 or u.2.

Might be good to keep your active data on full flash array and use the hdds as backup only.

 

[elag]

Intel guarantees powerloss protection only for the datacenter Optane model 4800x although the risk on the desktop models seems low.

I have made some tests with the 32G Optane. Sync performance is way below the upperclass models up from 800P, more near a good Sata SSD. I have had also a lot of problems with it (not working in any configuration/OS). see https://napp-it.org/doc/downloads/optane_slog_pool_performane.pdf

If you can afford, start with the 800p-58.
If this is not for home use, buy the datacenter model 4801X-100 GB with guaranteed powerloss protection.

thanks for the information. I missed the 800p in my searches, but it looks indeed more attractive. the price difference is not that huge, so the 800P is what I will go for. The risk going for something without PLP seems manageble. I assume that an ongoing sector write may fail, but I would guess that write will not yet be confirmed. Any power outages are really rare here. It is more likely that I unplug power by moving something around (has happened before...)

 

[elag]

Sync writes and raidz2 are gonna have significant impacts on performance.

Seeing that data intergity seems to be a high priority for you, you should consider a PLP enabled drive for slog.

In your case a P3700 seems a good option can be had reasonably, which can be aic or u.2 to m.2 converted.

If you don't mind spending more, I agree with @gea that the p4801x (100gb) is an obvious choice. See: https://www.servethehome.com/intel-optane-dc-p4801x-review-100gb-m-2-nvme-ssd-log-option/

Also, with bifurcation supported on your, x16 you also have the option of going 4x nvme at full speed in either m.2 or u.2.

Might be good to keep your active data on full flash array and use the hdds as backup only.

I understand your concerns, data integrity is important but not at all costs. Going for an Optane with PLP is too expensive for me right now. I like your comment about the option to use 4*NVME in the x16 slot. This will however need to be reserved for a future project as I am running out of funds as is. But I am already dreaming of adding 4 larger SSDs (2 - 4TB) with PLP