Hello - New to TrueNAS, setting this up for the first time. I have a very good understanding of RAID sets but for some reason I can’t wrap my head around the disk setup options.
I have a Dell R620 with 8 SAS 600GB drives. I also have 2 spare 1TB SSD drives I would like to use instead of 2 of the 600GB. The server also comes with Mirrored SD cards that I can put 2 32GB cards in and run the OS off that as an option.
I have already flashed the RAID card to IT, TrueNAS sees the disks and I can boot from them as it currently stands.
Question (Home setup):
How would you install TrueNAS and configure the disks for multi-purpose use?They are, security camera storage, VMs, general playground for self learning new things.
Do you really have to use such small disks? I’d toss them and mirror a pair of 6-8 TB CMR spinners.
Really wouldn’t recommend this–the boot device is a live ZFS pool, and SD cards aren’t known for R/W endurance. A small SSD (or a pair of them if you like) is a much better bet.
Two pools. One with the SSDs (mirrored VDEV) for VMs and Apps, another with the HDDs (for the security camera storage).
Depending on your requirements (space?) you have likely two options for the HDD pool:
A single 6-wide RAIDZ2 VDEV (gives the most space and higher resiliency);
3x 2-way MIRRORED VDEVs (gives the most iops, gives you less space).
Going with mirrors also means more flexibility for future expansion.
Suggested reading:
Be aware that data is constantly being written to the boot pool.
The primary drawback is that SD cards are not meant for continuous writes so only hypervisors that do not routinely write to the OS partition are supported. A second drawback is that reads and writes are slow so it works best for OS’s that are fully load into memory during the boot process.
This means that they are absolutely unsuitable for TrueNAS.
Dell’s spec sheets for servers are not very explicit in which OS’s can run from the SD card readers. The key term on the spec sheet is “Optional embedded hypervisors” under “Operating systems.” This is generally listed as Citrix XenServer and VMware vSphere ESXI.
If you are going to have a single HDD pool I would agree with this. Over the lifetime of your server the cost of electricity to spin these small drives will likely be more than the cost of 2 new drives.
8x 600GB in RAIDZ2 is 3.6TB - a pair of 4TB drives would be an equivalent size replacement. (RAIDZ2 because of width of the array and because the drives are (presumably) already quite old.)
However…
For VMs you want mirrored drives (ideally SSD but if not then SSD SLOG).
For security camera writes you need to decide whether you need redundant disks at all.
For normal NAS RAIDZ will be fine (or mirror if only 2 drives).
So I would guess that you need to decide first what types and size of pools you need for your various use cases, and then decide what it would be economic to use the existing 600GB drives for and what you really would be better off with new drives for.
