Target Disk Options

[Spartan67]

Hello everyone,

So my question is about when installing Proxmox you have the option to choose the filesystem (ext3 ext4 xfs or zfs). I am familiar with ext3 and 4 and have read up a little bit about xfs and zfs (just an FYI, I understand the raid levels associated with zfs), but what is the ramifications of choosing each of these for Proxmox...? Also, what is the default filesystem that is used if one isn't chosen and you take the defaults when installing? And lastly if you were to use different versions within a cluster what are the ramifications?

 

[oguz]

hi,

Also, what is the default filesystem that is used if one isn't chosen and you take the defaults when installing?

the default option is ext4.

but what is the ramifications of choosing each of these for Proxmox...?

please see our wiki page [0] about storage

And lastly if you were to use different versions within a cluster what are the ramifications?

chosen filesystem for the cluster node doesn't change anything. cluster nodes can have different storages on them without issue.

[0]: https://pve.proxmox.com/wiki/Storage

 

[Spartan67]

Hi Oguz, I read the Wiki and it helped but I have a follow-up question.

I ended up using zfs instead of the default ext4.

I have a four node cluster, on each node the nodes RAM usage is far greater than the total of all the VM's I have on that node.

So for instance I have a node with 32Gb of ram using zfs and two VM's one a Windows server 2019 with 4Gb and another an Ubuntu 20.04LTS with 4Gb for a total of 8Gb, but the node is reporting that nearly 24Gb out of 32Gb is in use.

I had a spare machine so I built a standalone node using ext4 with 16Gb of memory, I loaded 3 Ubuntu VM's each with 4Gb and a Windows with 4Gb, so a total of 16Gb for all VM's and the ram usage of the node is barely 9Gb.

So does zfs utilize memory whereas ext4 does not...?

 

[Spartan67]

Disregard my question I found the answer:

Limit ZFS Memory Usage​

ZFS uses 50 % of the host memory for the Adaptive Replacement Cache (ARC) by default.