Two Pools Sharing Same Disks

[HarryMuscle]

I'm pretty sure this isn't a recommended setup but I'm curious if TrueNAS is able to do this, either via the GUI, or if not, via the command line but in such a way that the GUI doesn't get all confused by the setup.

Assuming you have 8 disks in total, is it possible to create two partitions on each disk and then create two seperate pools, where the first pool is a raidz3 and resides on each disk in the first partition, and the second pool is a raidz2 and resides on each disk in the second partition? Data that requires higher redundancy for extra uptime would reside on the first pool and data that requires less redundancy would reside on the second pool.

Thanks,
Harry

 

[NugentS]

As per reddit - yes you can. See an Art of Server video on the subject
Highly not recommended though

 

[sretalla]

Assuming you have 8 disks in total, is it possible to create two partitions on each disk and then create two seperate pools, where the first pool is a raidz3 and resides on each disk in the first partition, and the second pool is a raidz2 and resides on each disk in the second partition? Data that requires higher redundancy for extra uptime would reside on the first pool and data that requires less redundancy would reside on the second pool.

See an Art of Server video on the subject
Highly not recommended though

Be aware that if you decide to do that anyway, there will be (at least) 2 consequences...

Potentially disastrous performance of both pools at random times for many different and unpredictable reasons.

You will never be able to do a disk replacement of a failed disk from the GUI (and all disk replacements will need to be done on both pools simultaneously, but in sequence to avoid IO contention).

 

[HarryMuscle]

As per reddit - yes you can. See an Art of Server video on the subject
Highly not recommended though

Thanks, I'll take a look.

 

[MechWarriorZero]

I created two partitions on the same drive and install truenas but the installer didn't see the two partitions on the same drive

 

[NugentS]

I created two partitions on the same drive and install truenas but the installer didn't see the two partitions on the same drive

Are you talking about the boot-pool here or a data pool?
If datapool, then you will need to create the vdevs at the CLI, the GUI will not work

 

[MechWarriorZero]

one partition for the boot-pool and the second partition for apps, I create two partitions in windows by splitting them, then I install truenas the installer uses the hole drive

 

[Whattteva]

Assuming you have 8 disks in total, is it possible to create two partitions on each disk and then create two seperate pools, where the first pool is a raidz3 and resides on each disk in the first partition, and the second pool is a raidz2 and resides on each disk in the second partition? Data that requires higher redundancy for extra uptime would reside on the first pool and data that requires less redundancy would reside on the second pool.

I really don't understand why you'd want to do this. It makes no sense for a number of reasons:

• Your goal is to improve uptime but you're using the same physical disks so it kinda' defeats the purpose.
• Improving uptime is achieved by increasing the RAIDZ number (aka more physical disks).
• Doing things in unsupported ways tend to increases your chances for a catastrophic failure defeating your initial purpose of increasing uptime.

That being said, this looks like a cool little experiment to do in a lab, but there is no chance in hell I'd be doing something like this on production-level machine.

 

[Patrick M. Hausen]

one partition for the boot-pool and the second partition for apps, I create two partitions in windows by splitting them, then I install truenas the installer uses the hole drive

Partitioning the boot drive is not supported. But you probably guessed as much. It is advised to use a reasonably priced small SSD for booting like e.g. the Transcend 370S series.

 

[danb35]

I created two partitions on the same drive and install truenas but the installer didn't see the two partitions on the same drive

I have to waste an entire drive just for booting?

This resource was originally created by user: jgreco on the TrueNAS Community Forums Archive. Please DM this account or comment in this thread to claim it. With the advent of TrueNAS Scale, we seem to be getting a large number of people from the Linux community who are not quite grasping what...

www.truenas.com

 

[Stux]

I'm pretty sure this isn't a recommended setup but I'm curious if TrueNAS is able to do this, either via the GUI, or if not, via the command line but in such a way that the GUI doesn't get all confused by the setup.

Assuming you have 8 disks in total, is it possible to create two partitions on each disk and then create two seperate pools, where the first pool is a raidz3 and resides on each disk in the first partition, and the second pool is a raidz2 and resides on each disk in the second partition? Data that requires higher redundancy for extra uptime would reside on the first pool and data that requires less redundancy would reside on the second pool.

Thanks,
Harry

I’ve done this a few times but normally only temporarily.

I did bodge up a backup server recently with a bunch of different sized disks and by clever partitioning and vdev placement was able to maximize capacity with 1 disk redundancy.

Ie raidz1 across all the disks. then another across the larger disks. And finally a mirror on the two largest disks.

Which gave me the space to replicate a pool so I could then rebuild it in a different topology.

Etc.

Not recommended for actual use.