[PVE-User] Proxmox VE 3.4 released! - Quick ZFS test

[Pongrácz István]

----------------eredeti üzenet-----------------
Feladó: "Martin Maurer" martin at proxmox.com 
Címzett: pve-user at pve.proxmox.com, pve-devel at pve.proxmox.com 
Dátum: Thu, 19 Feb 2015 14:38:39 +0100
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> Hi all,
> 
> We just released Proxmox VE 3.4 - the new version is centered around
> ZFS, including a new ISO installer supporting all ZFS raid levels. 



Hi,

Thank you for your effort, it is really cool to have zfs support out of box!

I just did a quick test of the new installer and check the settings of the pool and the logic behind it.

Generally I like it very much!

Some notes from my experiences:

- pve uses the latest stable zfsonlinux

- pve 3.4 put the root filesystem into the ZFS pool -> awesome, very handy, safe, etc.

- it use ashift=12 -> pretty cool, always recommended

- it use gzip-6 compression by default -> as the system supports lz4 compression, I recommend to use this one instead of gzip-X. In general. Of course, it is possible to change the compression on the fly (for newly written blocks) but for general usage, lz4 needs less power and provides a really nice compressratio.

- it use a swap on the rpool -> I am not sure, it is a good idea to have swap on zfs, even it seems cool. Depends on the memory allocation, zfs memory fragmentation overhead etc., so, be careful with this option.

- it has zfs default ARC size (1/2 of the available physical RAM) -> plan ahead and calculate your memory map: VMs, CTs, twice of ARC (rule of thumb). Limit ARC to a lower value if you have not so much "free memory".

- the installer does not provide l2arc/zil, but it is easy to add/remove them later. Depending on your system, you can set them on 2 or more SSDs. Probably not everybody need them, depends on the using profile.

- it can use thin provision for VMs, which pretty cool (sparse zvol).



In general: before somebody put his system to production but he/she is new in ZFSonLinux world, I strongly recommend to test the system and care about the memory map (how many allocated/dedicated to ARC, VMs, CTs).

The fun begins :)

Bye,
István