I want to build a truenas server with the cheapest CPU I can find that can support ECC RAM: Celeron G4900T + 64gb ECC RAM + 4x18 TB SAS drives.
I don’t have experience with ZFS or with truenas (core or scale), how much important is the CPU?
Use case: hundreds of thousands of small files mostly under 1 mb, but just 2-3 concurrent users
You don’t mention your performance requirements and I’m unfamiliar with that CPU. Are you trying to saturate your 1G presumably NIC? Reads or writes?
No, just thousands of small files. Windows takes around a minute to enumerate all the files in the main share via SMB
@Moonrise2473
That looks more like ARC problem, it can hold a large index of the filesystem if you give it enough room in ram, avoiding the need to seek thousands of files on a spinning disk, which takes time. HDDs are fine for sequential operations, Random IO, which is your usecase, is their biggest weakness.
@eleitlYou should be good, then. Probably don’t need SSDs for ZIL and L2RC either. Don’t forget to schedule a weekly scrub, to catch bit rot. Essential for large drives.
reason why i use a C246 motherboard and other high end expensive components, but such a cheap cpu: someone will sell me used supermicro mobo+ECC ram+SAS HDDs for 500 euro, but no CPU. A Celeron G4900T costs like 15 euro, i was wondering if it could suffice, because this is already overkill for me, at the moment i have no idea on how to use the 36 TB of storage (2x redundancy)
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@Moonrise2473
CPU is not that important for ZFS itself, but it’s important for network communication. If you plan to saturate 1G connection or faster with your storage, you will need a CPU with solid single-threaded performance, or a discreet “smart NIC” aka DPU, but that’s really for way bigger speeds.
If you plan to use a couple of spinning rust drives with no ssd cache, you are fine with any reasonably modern CPU (like Core/Xeon ~2012 and newer, Atom ~2016 and newer).It’s ok until you start using jails or dedup.
ZFS tends to be more RAM intensive so make certain you have, at bare minimum around 16GB. But I would push for more.
@housepanther
As Lawrence said: “It’s not ram intensive, it’s ram efficient.”
It doesn’t let ram sit there unused. So you only really need 1G of ram per 1T of storage in general, outside some very rare cases. But the more ram you throw at it, the more snappy it becomes, but there are some diminishing returns. For example, 128G of ram on a 20T array won’t be fully utilized most of the time.
L2Arc raises ram requirements, because you also need to store it’s index there.
@Moonrise2473
In my (admittedly) limited experience with ZFS, it utilizes more RAM than CPU except for scrubs.
If you’re wondering about the downvotes, I got brigaded by PRC simps. Lemmy doesn’t yet have the protection against this that Reddit had.
