Proxmox 4.1 partitioning

[tomic]

Hi there,

i would like to install proxmox on 2 different servers with zfs and have some problems....

My constellation:
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Server1
2 x Intel SSD 120GB (Raid1 on 3ware Controller)
2 x 2000GB Seagate HDD (Raid1 on 3ware Controller)
Of course, proxmox detects for each raid respective one single disk.

Server2
5 x 3000 GB Seagate HDD (Raid5 on 3Ware Controller)
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Is there any possibility to create partitions with zfs?
I would like to use zfs because of the direct access to the root fs of the lxc.
see this thread: https://forum.proxmox.com/threads/proxmox-4-lcx-fs.24049/#post-120936

many thanks and best regards

tomic

 

[wolfgang]

Hi,

You can make subvols and set the mount point.

P.S. be sure you use a HBA Firmware for the 3ware Raid, if you use ZFS on top of it.

 

[tomic]

thank you wolfgang for your reply...

i am not able to use zfs with a single raid volume for the proxmox installation.
Because the installation wizard of proxmox only let me chose zfs raid 0, 1, 5, 10 etc.

Do i have to create single JBOD for each hdd? that would reduce the benefit of a dedicated raid-controller.

 

[vkhera]

If you want to use ZFS on a handful of drives, do not bother with a RAID controller. ZFS really likes it much better and is more robust when it manages the multiple devices. Now, if you had say 100 drives each connected in a RAID10 and presented as 10 or 20 logical volumes, then you could use each of those logical volumes as a ZFS device.

Exactly what benefit of a dedicated RAID controller are you afraid of losing?

 

[tomic]

benefits for me:
+ faster because of caching
+ battery backup unit (bbu) to prevent data loss
+ more connectable devices possible (onboard are 6 S-ATA-Ports. 8 ports or more on a 3ware Controller.

so you would prefer to connect the drives directly to the onboard sata controller, right?

 

[SwampRabbit]

ZFS was designed to cover the benefits you discussed and more.
It isn't for everyone in every situation, but in some situations it can outperform and overly protect data compared to traditional RAID and filesystems. Just like many things, there are Pros and Cons, it is really up to you if you want/need to use it.

ZFS likes RAM, the more the better, and SSD for caching can do wonders too.
ZFS does not work well when there are layers between it talking to the drives.
Some RAID controllers still do not work properly even when in JBOD mode when using the RAID mode firmware. You will have to research if your 3ware controller has known problems. What 3ware controllers do you have? Maybe someone here has tried them with ZFS.

You can connect the drives directly to the onboard sata controller and it should work fine.

If you need additional connections you can do like Wolfgang said and use a HBA or RAID controller which allows loading of "IT mode" firmware. For ZFS the IBM M1015 is very popular in some circles. I use some IBM M1115, which is pretty much the same. Both can be found online pretty cheap, sub $100USD.

If you have very good 3ware controllers, do not have RAM in your hosts to spare just for ZFS, or do not have a SSD for caching then ZFS might not be for you at this point in time.

Fully understanding ZFS is important, once you understand the Pros and Cons, you'll be able to determine if its something you really want/need.
http://zfsonlinux.org/faq.html

 

[vkhera]

benefits for me:
+ faster because of caching
+ battery backup unit (bbu) to prevent data loss
+ more connectable devices possible (onboard are 6 S-ATA-Ports. 8 ports or more on a 3ware Controller.

so you would prefer to connect the drives directly to the onboard sata controller, right?

I suppose you can think of ZFS as a software RAID controller, because it handles the cache, the data loss prevention (using the ZIL). You can tune and upgrade the various bits as needed, too. When was the last time you got a RAID controller with expandable RAM? I had one once, but could never get the RAM chip for it... as for more connectable and faster devices, that's why I purchase the LSI SAS controllers. They're cheap and let you connect lots of drives.

As stated above, you need to review the pros and cons and decide which way to go. Personally, I'm not getting any more systems with hardware RAID controllers. I've had enough disk failures that the controllers couldn't handle (without reboot) to trust them anymore.