A bit of advice on scale

[Bryon Brinkmann]

First I have to say, Great Job on TrueNAS Scale! Super digging it. I was thinking about using a competitor but, you have to buy a license.

Question: I have 2 liberated Dell R630's with both 2 Intel(R) Xeon(R) CPU E5-2697 v3 @ 2.60GHz, 300+ DDR4, blah blah blah.

Dell one = 10 2TB SAS & 2 120GB SATA-DOM's. booting off 2 mirrored 64GB USBs (was using 1 DOM to Boot the other as a cache but one poo'd itself so. I elected to go with USBs ).
Dell two = 8 4TB SSD's, 2 TB SSD's and 2 120GB SATA-DOM's. Ditto as above; DOM 1 Boot & DOM 2 cache.

SATADOM's are $$ and a bit hard to find. I think they are POS's my opinion.

I bought a PCI E NVME card and a 128GB NVME SSD to install into it. SUPER GOOD PRICE! So I was thinking to install it into Dell one to use for caching.
Links here:
NVMe Card
NVMe Solid State Drive M.2

Do you think there is any benefit or this is just a waste of $$$? Hell, I don't even know if they are compatible.

 

[diskdiddler]

I have run TrueNAS from dual usb sticks for 7 years.

You do not need a fancy drive.

 

[Bryon Brinkmann]

I have run TrueNAS from dual usb sticks for 7 years.

You do not need a fancy drive.

Yeah, I'm kinda thinking the same thing. But still wondering if it would benefit cache writes to the spinning disks.

 

[diskdiddler]

Yeah, I'm kinda thinking the same thing. But still wondering if it would benefit cache writes to the spinning disks.

I believe some kind of log file or some such can be written to a high speed disk but I am unsure of the major benefits.
Also I would syspect it could not be the boot disk.

I would legitimately boot TrueNAS from a 2.5" 20GB mechanical SATA if I had no choice (again I'd prefer always 2x of them tho)

Others here will be much smarter, in regards to high performance caching options, tho I think more memory is the big benefit for the system and more processor. Depending on how many people hit and what for.

 

[Patrick M. Hausen]

A dedicated SLOG device will only benefit you if your pool has got a bottleneck for synchronous writes. These never happen if you use only SMB file sharing. Most common scenario for sync writes is backend storage for VMs via iSCSI or NFS. If you don't use this, you probably don't need an SLOG.

Read the ZFS primer and/or jgreco's excellent post about block storage:

ZFS Primer

Background information about the Zettabyte File System (ZFS).

www.truenas.com

Resource - Sync writes, or: Why is my ESXi NFS so slow, and why is iSCSI faster?

This post is not specific to ESXi, however, ESXi users typically experience more trouble with this topic due to the way VMware works. When an application on a client machine wishes to write something to storage, it issues a write request. On a...

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