Problem Adding SLOG device

[mullinsj08]

Hi Guys,

I just purchased a 512GB Samsung PM961 NVME M.2 SSD to use as a SLOG device and installed it into my FreeNAS box.

I'm getting weird errors when trying to assign it to one of my pools as a SLOG, see picture below...



In the GUI, the volume manager is hung...



These are my system specs:

- SuperMicro X10SRi-F Motherboard
- Intel Xeon E5-1620 V3 CPU
- 32GB DDR4 ECC PC4-2400 RAM (More to be added soon to make up 128GB)
- x2 LSI SAS 9207-8i HBA
- FreeNAS 9.10 Update 2

The M.2 SSD is sitting in a PCI-E > M.2 Adapter in a PCI-E x8 (x4 Electrical) slot.

Any help would be greatly appreciated!

 

[dlavigne]

I'm not seeing your images. Can you try attaching them again?

 

[mullinsj08]

My bad! The images are there now.

Quick update: I booted my FreeNAS into an Ubuntu live CD, formatted the SSD and copied a file to it OK. I then tried to add it as a SLOG device to my FreeNAS again and it added after a few hours but now shows in a 'FAULTED' state because of persistent errors.

 

[mullinsj08]

I've given up with the Samsung PM961 SSD and decided to RMA it.

I'll replace it with a 240GB Corsair MP500 which is a bit cheaper and has more write speed which I'll need because I'll have a dual port 10GB NIC in the FreeNAS and 2 ESXi hosts also with 10GB NIC's connecting back to it

 

[Ericloewe]

Neither of those is appropriate for SLOG. You need power loss protection for SLOG, otherwise it's practically as bad as running with sync disabled, but with crap performance.

 

[mullinsj08]

OK, do you know of any NVMe SSD's that have power loss protection and about 2000MB/s write speed?

 

[Ericloewe]

The standard solution is the intel P3700.

 

[Amu W Ramappa]

The standard solution is the intel P3700.

Yup. If you can afford two of those for protection on failure then you'll be in a good place.

Sent from my Nexus 6P using Tapatalk

 

[Sakuru]

https://forums.freenas.org/index.php?threads/some-insights-into-slog-zil-with-zfs-on-freenas.13633/