TrueNas Core partitions setup (boot - SLOG - L2ARC)

Julien_d

Cadet
Joined
Feb 13, 2022
Messages
3
Dear all,

My name is Julien and I am glad to join you on this forum to install my first TrueNAS DYI system. I have spent some time reading the available documentation and diverse forum posts, and now I would like to confirm with you a few points as I am still not totally familiar with TrueNAS Core.

If possible, I would greatly appreciate recommendations / advices on the below setup.

The need is simple: to configure a stable storage system where I can store Photo, video, documents and slowly explore the capabilities of TrueNas Core by later installing apps and add-ons in dedicated Jails.

The hardware I have at the moment:
  • A motherboard with 4 x SATA 6Gbps
  • An Intel CPU
  • 16 GB DDR4
And as storage
  • 1 new SSD NVMe SAMSUNG 970 EVO PLUS 250GB
  • 6 HDD 10 TB SATA 6Gb/s
  • 1 old SSD SanDisk Extreme PROD 240GB SATA 6Gbps
  • 1 old SSD Crucial m4 256Gb SATA 6Gbps
First question on hardware

My motherboard provides only 4 x SATA 6Gb/s (8 would be needed).
-> what would be the best PCI to SATA extension card to add another 4 ports knowing the motherboard has:
  • 1 x PCI Express 5.0
  • 1 x PCI Express 4.0
  • 2 x PCIe 3.0

Following questions on storage partitions
Is it possible to configure the storage as below?

1] Boot partitions + SLOG partitions mirrored on these two SSD:
  • 1 old SSD SanDisk Extreme PROD 240GB SATA 6Gbps
  • 1 old SSD Crucial m4 256Gb SATA 6Gbps
Installation of boot partition on 1 SSD then setup of the mirror on the 2nd SSD is clear: when installation completed, setup the mirror boot partition on the 2nd SSD (and remembering to enable boot device for the second SSD).

However I am not sure yet if that's a good idea to add the SLOG partition on the boot SSD, then mirror it on the 2nd one. Can it be done?
I thought of this setup to avoid using the NVMe for both SLOG and L2ARC as I read it was not a smart move in terms of performances.

Also, does the "16Gb SWAP" partition created at the installation on boot device actually refers to L2ARC?
If yes, should this installation step be skipped to later create a L2ARC on the NVMe instead?

2] L2ARC partition on the new SSD NVMe
  • 1 x SAMSUNG 970 EVO PLUS M.2 2280 250GB
-> Does it even make sense to use this SSD NVMe for L2ARC?
-> If yes, what should be the right size for this L2ARC partition?
-> If there is remaining space, can it be used for another purpose?

3] RAIDZ2 with the 6 x 10TB NAS Hard Drives
  • 6 x HDD 10 TB SATA 6Gbps
I am still reading the documentation, but based on this post I would assume a RAIDZ2 would work with 6 HDD to have 40TB usable space.

Many thanks in advance for your advices. Happy Valentines day!
 

jgreco

Resident Grinch
Joined
May 29, 2011
Messages
18,681
Is it possible to configure the storage as below?

1] Boot partitions + SLOG partitions mirrored on these two SSD:

No. TrueNAS requires separate devices for boot devices and pool devices. Device sharing is not permitted. You should probably forget the use of the word "partitions" in every instance in your post and replace it with "drives".

While you can force such shared "partition" setups manually via the CLI, they are hazardous to maintain, and in this case:

  • 1 old SSD SanDisk Extreme PROD 240GB SATA 6Gbps
  • 1 old SSD Crucial m4 256Gb SATA 6Gbps

these are useless as SLOG devices. They do not have the necessary qualities, namely, endurance and power loss protection. Just skip the SLOG.

2] L2ARC partition on the new SSD NVMe
  • 1 x SAMSUNG 970 EVO PLUS M.2 2280 250GB
16 GB DDR4

L2ARC is generally not recommended until you get at least 64GB of memory, and even then, the size of an L2ARC device should be limited to about 5x the size of RAM, no larger than 10x the size of RAM.
 

Etorix

Wizard
Joined
Dec 30, 2020
Messages
2,116
16 GB may be a bit short to use jails/VMs—and definitely not enough to even consider L2ARC.
I'm 99.99% certain you do NOT need a SLOG to begin with.

PCIe 5.0 indicates this is a last-generation consumer motherboard… so you're heading for trouble with Alder Lake support. Getting a proper server-grade motherboard from a previous generation, possibly used, and preferably with 6-8 SATA ports directly onboard, would lead to a better TrueNAS experience than recycling consumer/gamer hardware.
Does the board has a Realtek NIC by any chance? These work poorly with CORE.

Otherwise, you need some HBA card (not a "RAID" card!), based on LSI 2008 (a bit old), LSI 2308 or LSI 3008 for the drives. Better get a new motherboard than work out one limitation after another (HBA, NIC,…).
 

Julien_d

Cadet
Joined
Feb 13, 2022
Messages
3
Hello Jgreco, many thanks for this swift reply, it does help a lot to put aside some scenarios indeed.

Based on your answer I would guess I should go for these scenarios. Does it make sense?

1] Boot device mirrored on these two SSD:
  • 1 old SSD SanDisk Extreme PROD 240GB SATA 6Gbps
  • 1 old SSD Crucial m4 256Gb SATA 6Gbps
OR

2] Boot device just on
  • 1 x SAMSUNG 970 EVO PLUS M.2 2280 250GB
Just trying to see what I can do to make the best of my current storage devices.

Also, may I ask about these two questions as well?
My motherboard provides only 4 x SATA 6Gb/s (8 would be needed).
-> what would be the best PCI to SATA extension card to add another 4 ports knowing the motherboard has:
  • 1 x PCI Express 5.0
  • 1 x PCI Express 4.0
  • 2 x PCIe 3.0
does the "16Gb SWAP" partition created at the installation on boot device actually refers to L2ARC?

Many thanks
 

Julien_d

Cadet
Joined
Feb 13, 2022
Messages
3
Yes you guys are super fast, that's amazing thank you.

The motherboard is really new yes, but luckily using an Intel NIC not Realtek. I will give the installation a chance on 1 of the old SSD with 2 HDD and see how happy to feels before moving forward to further setup. Thanks again
 

Etorix

Wizard
Joined
Dec 30, 2020
Messages
2,116
The i225V driver just landed in TrueNAS, so this is a start, but depending how many bugs it may still have, you may not be totally out of trouble.
Mirrored boot device makes little sense for a home or homelab NAS. Just keep a copy of the configuration file on your PC; if the the boot device fails, change it, install anew and load the configuration file.
Booting from NVMe will keep all 4 SATA ports free for HDDs.

Oh, if you search the forum, you'll find instructions to partition drives for both boot and a small (jail) pool. But this configuration is not officially supported (here be dragons and all that sort of things…), and then you'll really need a HBA to have two mirrored SSDs as boot+jails and a reasonable number of HDDs.
 
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