SLOG - Actual Device Model Number List NVME Only

[webdawg]

I was reading the hardware recommendations guide, and it was talking about the Intel DC P3700.

I think I want to SLOG, but I have to check if their are any PCIe slots avail before I do. I am going to mirror my SLOG: https://www.reddit.com/r/zfs/comments/6p6jiy/worth_mirroring_slog/

I am going to only do NVME.

Does anyone have any links to a list of NVME battery backed up/whatever units that are 100% acceptable as SLOG?

Intel I guess:

Some googling found this: https://www.truenas.com/community/threads/list-of-ssds-with-power-loss-protection.63998/

 

[HoneyBadger]

It's a long thread, but there is a collection of SLOG benchmarks here.

SLOG benchmarking and finding the best SLOG

I'd like to take a few minutes to talk about SLOG devices and what makes good ones versus bad ones. I have no doubt that this will be a controversial topic since this is not well understood by many people. In short, there's 3 things that you need for a "great" SLOG: 1. Fast throughput 2...

www.truenas.com

Your Intel P3700 is among the heavy-hitters, the "prosumer" Optane 900p/905p is also well-represented, as of course are the "enterprise" Optane DC P4800X and P4801X. A popular used/refurbished device is the Radian RMS-200, a battery-backed NVRAM card with 8GB of space.

Trying to crosslink a graph here, hopefully it works. A bit out of date in that I need to add the RMS-200/300.

 

[webdawg]

Thanks, I will take a look and let you know.

 

[webdawg]

I was trying to find the graph in the thread, I get that the x axis is size, what is the y axis?

 

[HoneyBadger]

I was trying to find the graph in the thread, I get that the x axis is size, what is the y axis?

Sorry about that. X axis is the ZFS recordsize in kilobytes, Y axis is transfer speed in MB/s. Need to add some minor gridlines for sure.

Another question to ask is "do you need an SLOG" - unless you have a sync-write workload (eg: NFS shares or virtual machines) then an SLOG device could go entirely unused.

 

[webdawg]

Should I do an SLOG mirror? I think I have a lead on two good costing ones

SSDPEDMD800G4

Should I get one or two?

 

[webdawg]

Wait, I already found that answer:

Reddit - Dive into anything

www.reddit.com

 

[HoneyBadger]

Wait, I already found that answer:

Reddit - Dive into anything

www.reddit.com

This answer looks good to me:

If you're running critical business functions on ZFS where any data loss is unacceptable, mirror your (bleep)ing SLOG.

Bingo.

 

[webdawg]

is this a good drive?: SSDPEDMD800G4

 

[Patrick M. Hausen]

With the people who know [tm] in this thread, may I hijack it for one small question?

I have read on this forum about Intel 900P, P3700, ... and the like. I wonder what kind of device I have in my system. I put it in there because it read "Optane" and it was left over @work. And I still had a free M.2 slot on my mainboard. I don't have a clue really, what precisely this is and the Intel product page does not help, either.

Device identifies as: MEMPEK1J032GA
Intel says it's an Optane M10 series: https://ark.intel.com/content/www/u...es-16gb-m-2-80mm-pcie-3-0-20nm-3d-xpoint.html

And I have never seen that mentioned here anywhere. Is this really unsuited for an SLOG device?

Thanks!
Patrick

 

[HoneyBadger]

Intel Optane Memory 32GB is what you've got. I know because I'm holding one in my hands (well, the box at least - the card's in a system.)

Fine for lower-utilization systems, it has the inherent "PLP-protection" of being 3D XPoint. It won't keep up with a 10GbE network but 2x1GbE will be handled admirably.

 

[Patrick M. Hausen]

Fine for lower-utilization systems, it has the inherent "PLP-protection" of being 3D XPoint. It won't keep up with a 10GbE network but 2x1GbE will be handled admirably.

Thanks. Then why are these not mentioned more frequently? They are comparably dirt cheap:

Intel Optane Memory M10 16 GB PCIe M.2 80mm at Amazon.com

Buy Intel Optane Memory M10 16 GB PCIe M.2 80mm: Memory - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[HoneyBadger]

Thanks. Then why are these not mentioned more frequently? They are comparably dirt cheap:

Intel Optane Memory M10 16 GB PCIe M.2 80mm at Amazon.com

Buy Intel Optane Memory M10 16 GB PCIe M.2 80mm: Memory - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

That's the 16G model you've linked; it's only good for about 1Gbps of sync writes, vs. the 32G which can do double that.

They don't have the endurance needed to withstand a heavy write workload (365TBW) and they're also M.2 which means you either need the NVMe-capable slot or have to buy a carrier card for PCIe.

They've been posted in the "SLOG Thread" a few times as well as the larger 800p 58G.

 

[Patrick M. Hausen]

They don't have the endurance needed to withstand a heavy write workload (365TBW)

Seems like I want to start graphing the total bytes written in my Grafana for all of my SSDs