Storage question

[eoinkim]

Hi all,

I am currently reading this documentation - https://pve.proxmox.com/wiki/Storage and have some questions regarding storage types. Currently, I have configured a FreeNAS box with a ZFS pool (raidz2 with 4 hard disks).

1. The doco says 'On file based storages, snapshots are possible with the qcow2 format'. I'd like to know more about this. For example, if I connect the FreeNAS box to Proxmox node via NFS, do I have to create a VM with only qcow2 hard disk to be able to create VM snapshots?
2. Does the same rule apply to thin provisioning? Again, for example, if I use FreeNAS with NFS, only qcow2 supports thin provisioning?

Thanks a lot.

Eoin

 

[tim]

ad 1. yes
ad 2. yes

As long as the storage type does not support a feature you will need qcow2 for it.

 

[LnxBil]

raidz2 with 4 hard disks

Do you really need the requirement that any two disks can fail? If not, use a stripped mirror which offers the same space, but better throughput.

I have configured a FreeNAS box with a ZFS pool

Why don't you use ZFS-over-iSCSI and have snapshots, thin-provisioning and the best performance (due to the smallest number of layers)?

 

[eoinkim]

Do you really need the requirement that any two disks can fail? If not, use a stripped mirror which offers the same space, but better throughput.



Why don't you use ZFS-over-iSCSI and have snapshots, thin-provisioning and the best performance (due to the smallest number of layers)?

Hi,

The thing is the system will host more than 40 customers' infra so, I guess raidz2 might be required for safety. My environment is sandpit but exactly the same configuration will be applied to production (of course, much bigger size). Do you think stripped mirror setup will be still fine?

ZFS-over_iSCSI is not supported out-of-box on Proxmox as far as I know with FreeNAS because FreeNAS is not using istgt anymore. I know there is a git project and I actually have tested. Just want to check performance at this stage. Thanks for that.

Eoin

 

[LnxBil]

The thing is the system will host more than 40 customers' infra so, I guess raidz2 might be required for safety. My environment is sandpit but exactly the same configuration will be applied to production (of course, much bigger size). Do you think stripped mirror setup will be still fine?

I don't know what your 40 customers do, but I would not use one single raidz2 vdev with spindels for myself in any way. A stripped mirror is much faster (up to 4x faster depending on what you measure).

ZFS-over_iSCSI is not supported out-of-box on Proxmox as far as I know with FreeNAS because FreeNAS is not using istgt anymore. I know there is a git project and I actually have tested. Just want to check performance at this stage. Thanks for that.

Hmm, It's also quite easy to build a ZFS Server for yourself. This tutorial is from @fireon and in german, but the commands may be useful for you.

 

[eoinkim]

I don't know what your 40 customers do, but I would not use one single raidz2 vdev with spindels for myself in any way. A stripped mirror is much faster (up to 4x faster depending on what you measure).



Hmm, It's also quite easy to build a ZFS Server for yourself. This tutorial is from @fireon and in german, but the commands may be useful for you.

Hi,

Thanks for the link, very good to know. I'll give a go although I cannot understand German. The reason I am using FreeNAS is because it's easier to maintain in my opinion. I am seeking an easier maintenance option e.g. showing/replacing faulty disks, replicating the whole storage to another etc., if that makes sense. I am not an expert for ZFS unfortunately (I wish I was).

I'd like to know about stripped mirror option you mentioned before. Is this another RAIDZ option or something else? Thanks again.

Eoin

 

[LnxBil]

I am not an expert for ZFS unfortunately (I wish I was).

I can recommend the books by Allan Jude (FreeBSD Mastery: ZFS, and the Advanced one)

I'd like to know about stripped mirror option you mentioned before. Is this another RAIDZ option or something else? Thanks again.

A stripped mirroring is like RAID10, so you have a two vdevs that are mirrored. You will get the most performance out of your 4 disks, but you have only 2 disks worth of space - as with raidz2 (comparable to RAID6 for old-RAID guys).