zfs on single ssd disk for vm storage

[juju01]

I have setup my install to have the following:

1. 2x 250 gb SSD in zfs raid1 for proxmox os.- nothing else here
2. 1x 1T SSD - I intend to use this to hold the VMS
3. Synology nas for backups ( NFS).

I am worried about the use of the single 1T ssd for the vms. I am planning to use zfs raid0 on it, but back up snapshots and the vms to the synology. But I read somewhere on another forum:

Never use ZFS on RAID 0 or with a single drive because basically you will get all the downsides of CoW with literally 0 benefit.

This was in relation to setting up postgres db with raid0 on a single disk.

My questions:

• Is this true about raid0 on a single disk? even with backups to my synology, is it a bad idea?
• using 250 gb for just proxmox os install doesnt seem like an optimal use of space. However, I have read so many times that its optimal to keep the os and vm separate? I contemplated using the 250 raid1 setup for both os and vm, but I think I will need a lot more space for my vm
• I am a bit confused as to how to sets.up an lxc container for a postgresql db. Does the container hold the actual database or do i have to option to store the database on another disk whilst just keep the vm on the 1T ssd )?
• finally, is it better to run a postgresdb in an lxc container or vm?

Would like some help to sort these out. thanks in advance!

 

[juju01]

anyone?

 

[guletz]

anyone?

Hi Juju,

.... and anyone try to help you ;}

even with backups to my synology, is it a bad idea?

Any form of backup is ok, especially when you lose your data. In any other situations, is a waste of time ;}

I have read so many times that its optimal to keep the os and vm separate? I contemplated using the 250 raid1

Me too! I do not belive this until PMX was not able to boot from zfs. Then I was think that any smart guy could separete the data(VM and/or CT) from the OS. But you do not need to belive me ...

Does the container hold the actual database or do i have to option to store the database on another disk whilst just keep the vm on the 1T ssd

This is not so clear question for me! Maybe you want to detail the both variants .... I am not very sure that I can gues about what you think!!!

finally, is it better to run a postgresdb in an lxc container or vm?

If you can define what is"better" for yout point of view, I could answer!


Until then, have a nice day

Good luck / Bafta !