Ext4 for my workload? Plus general questions.

[dekiesel]

Hi,

I bought a HP prodesk 600 G4, which I'd like to use with proxmox to replace my Rpi 4 (to give some idea about the expected workload).

I am undecided on which ssd to buy and was hoping for input on some questions.

I am more or less set on using ext4 since I'd like to reduce ssd wear as much as possible and because I don't have the money for an enterprise ssd (and I couldn't find an EU vendor for used enterprise ssds).

I have space for one m.2 and one sata drive. Should I buy two drives and put proxmox on one and the LXCs on the other? Is the expected wear less with LXCs?

I plan on testing out some "big data software" (airflow, spark, dagster, hop, kafka)...but I don't expect a big workload, I mainly plan on spinning up LXCs of those programs to find out how they should be configured to work together.

With how I am planing to use my setup: should I still expect high wear? Or is a consumer grade ssd fine since I am using ext4 (no write amplification) and don't plan on handling terabytes of data?

Thanks!

 

[leesteken]

I recently got an enterprise SSD (which can cache sync writes because of the PLP) and it's much quicker and will last a very long time. Spend the higher price once and live without worries about work-loads (but do keep making backups). Micron 7450 PRO/MAX M.2 is very affordable at thje moment.

 

[dekiesel]

I recently got an enterprise SSD (which can cache sync writes because of the PLP) and it's much quicker and will last a very long time. Spend the higher price once and live without worries about work-loads (but do keep making backups). Micron 7450 PRO/MAX M.2 is very affordable at thje moment.

Thanks, those seem ok (though still more than I paid for the G4)
Can I use zfs with those without worrying or should I stick with ext4?

Should the VMs be on separate disks still?

 

[dekiesel]

I ordered a micron 7450 PRO, thanks for the support @leesteken . I guess using zfs will be no problem and having the lxcs, vms on the same sad won't be a problem either.

 

[Dunuin]

I am more or less set on using ext4 since I'd like to reduce ssd wear as much as possible and because I don't have the money for an enterprise ssd (and I couldn't find an EU vendor for used enterprise ssds).

They start new at 42€, so not that expensive. If you don't want to buy a crappy QLC consumer SSDs, then its not that much more. Cheap Samsung Enterprise SSD for example maybe 25% more than a Samsung EVO consumer SSD.

Or is a consumer grade ssd fine since I am using ext4 (no write amplification)

There will still be write amplification. In my benchmarks I for example have seen a ext4 filesystem alone caused a factor 3-4 write amplification when doing 4K sync writes because of metadata overhead.
And then there will be additional virtualization overhead, overhead of the copy-on-write of the qcow2 format (without that you can't take snapshots or thin-provision on ext4), internal write amplification of the SSD doing sync writes, ...

 

[dekiesel]

They start new at 42€, so not that expensive. If you don't want to buy a crappy QLC consumer SSDs, then its not that much more. Cheap Samsung Enterprise SSD for example maybe 25% more than a Samsung EVO consumer SSD.


There will still be write amplification. In my benchmarks I for example have seen a ext4 filesystem alone caused a factor 3-4 write amplification when doing 4K sync writes because of metadata overhead.
And then there will be additional virtualization overhead, overhead of the copy-on-write of the qcow2 format (without that you can't take snapshots or thin-provision on ext4), internal write amplification of the SSD doing sync writes, ...

Thanks!

Are there any affordable Samsung enterprise ssds that you can recommend?

 

[Dunuin]

Cheap Samsung Enterprise SSDs are the PM883, PM893, PM9A3. A bit more expensive but more durable and faster is the PM897.
But can't personally recommend them, as I don't own them. But in contrast to consumer SSD, where they range from horrible to ok, the enterprise SSD are usually at least ok up to great.
With SSDs you basically get what you pay for. The cheaper the SSD is, the worse it will perform and the sooner it will fail.