Storage: ZFS

Introduction

tbd. (running zfs on Proxmox VE is not officially supported)

Native ZFS for Linux on Proxmox VE 2.X

2013-03-27: 0.6.1 ZFSOnLinux (ZoL) is now ready for wide scale deployment on everything from desktops to super computers. See announcement

check  http://zfsonlinux.org/ See the Documentation and Community Resources for more information and help.

I had tried 3 other operating systems including Debian/kFreebsd and for each was able to recover all the zfs file systems from previous installs. Even with disk name changes [bsd uses ad11, linux sdb ] no data was lost. Today I set up zfsonlinux using the following info on 2 prox 2.0 systems

using dkms

2013-05-29 - Debian Packages DKMS style packages for Debian are available from the zfsonlinux.org repository. These packages track the latest official upstream tag and are refreshed as new releases are made available http://zfsonlinux.org/debian.html .

• notes on changing from Ubuntu PPA method. note this needs to be refined as I did the install before removing the old ubuntu package.

remove ubuntu packages first.

aptitude remove ubuntu-zfs

move the old zfs.list from /etc/apt/sources.list.d

make sure pve headers are installed.

I think the ln is still needed.

then follow instructions from http://zfsonlinux.org/debian.html , i copied here , but check link in case these changed:

su -
wget http://archive.zfsonlinux.org/debian/pool/main/z/zfsonlinux/zfsonlinux_1%7Ewheezy_all.deb
dpkg -i zfsonlinux_1~wheezy_all.deb
apt-get update
apt-get install debian-zfs

---

Note (2013-03-17): this procedure worked well for PVE 2.3

# apt key
apt-key adv --keyserver keyserver.ubuntu.com --recv-keys  F6B0FC61

#sources:
echo "deb http://ppa.launchpad.net/zfs-native/stable/ubuntu lucid   main" > /etc/apt/sources.list.d/zfs.list

aptitude update

aptitude install dkms pve-headers-$(uname -r)

• this is needed for dkms to work:

ln -s /lib/modules/2.6.32-10-pve/build /lib/modules/2.6.32-10-pve/source

Maybe someone who knows how to write a patch could submit one and suggest this be done when kernel is upgraded? Otherwise I think when the Proxmox kernel upgrades, dkms build may fail if this is not done [ using new pve-headers ).

then install zfs

aptitude install ubuntu-zfs

finally make sure that zfs is started at system boot, edit /etc/default/zfs

# ZoL userland configuration.

# Run `zfs mount -a` during system start?
# This should be 'no' if zfs-mountall or a systemd generator is available.
ZFS_MOUNT='yes'

kernel upgrade

currently this needs to be done when a kernel upgrade occurs.

• before reboot:

2.6.32.11 upgrade from 2.6.32.10 did before reboot [ for you would need to change 2.6.32-11-pve if different version.

aptitude install pve-headers-2.6.32-11-pve
ln -s /lib/modules/2.6.32-11-pve/build /lib/modules/2.6.32-11-pve/source

• this will force modules to be built ( there is probably a better way to do this , so correct this if you know how to make dkms do the build ).

aptitude reinstall spl-dkms  zfs-dkms

using git

• install these

aptitude install build-essential gawk alien fakeroot zlib1g-dev uuid uuid-dev libssl-dev parted  pve-headers-$(uname -r) 

• get make and install spl

cd /usr/src
git clone https://github.com/zfsonlinux/spl.git
cd spl
./configure
make deb
dpkg -i *.deb
modprobe spl

• get make and install zfs

cd /usr/src
git clone https://github.com/zfsonlinux/zfs.git
cd zfs
./configure
make deb
dpkg -i *.deb

• make sure module can load

modprobe zfs

• install debs does not do this:

update-rc.d zfs defaults

• note , the deb files made above can be used to install zfs on another system.

• if there is a pre existing zfs pool then simply use the next line to recover it. this can happen if you re-install proxmox and have zfs disks from before.

zpoo  </cman>

• If there is a need or want I could set up a repository with pre build debs. Just send an email .

Creating Pools and Filesystems

use raidz2 or mirror in main data systems.

Create a raidz pool named “tank”

zpool create  -f -o ashift=12 tank  raidz  /dev/sda  /dev/sdb  /dev/sdc  /dev/sdd  /dev/sde  /dev/sdf  /dev/sdg  /dev/sdh

• note this happened to 2 or 3 disks the 1-st time. these were disks from a 3-ware raid.

zpool create  -f -o ashift=12 tank  raidz2   /dev/sda  /dev/sdb  /dev/sdc  /dev/sdd  /dev/sde  /dev/sdf  /dev/sdg  /dev/sdh
invalid vdev specification
the following errors must be manually repaired:
cannot stat /dev/sdg2: No such file or directory

had to use fdisk to add partitions 1 , 2 etc to those disks . I forget if I left the partitions there or not. but had to add to get this fixed.

NOTE: This is quite risky if you intend to deploy ZFS on a server. Any changes to the operating system's devices layout will break your pool. Don't create a pool using device names like /dev/sda. For persistence, use devices under /dev/disk/by-id. - Bryan Baldwin

Create directories and mount points

zfs create tank/data
zfs set mountpoint=/data tank/data

• mount all

zfs mount -a

destroy

to start over

zpool destroy zfs-pool

Setting Properties

• Automatically NFS-export all home directories [ I do not know how to use zfs nfs yet , or if it works yet in linux...].

zfs set sharenfs=rw tank/home

• check sharenfs

zfs get sharenfs tank/home
NAME     PROPERTY  VALUE     SOURCE
tank/home  sharenfs  rw        local

• Turn on compression for everything in the pool

zfs set compression=on tank

kvm tuning

see thread on prox forum , per user Nemesiz  :

• pool:

zfs set primarycache=all tank

• kvm config:
• change cache to Write Back

You can do it using web GUI or manually. Example:

ide0: data_zfs:100/vm-100-disk-1.raw,cache=writeback

if not set this happened:

qm start 4016
kvm: -drive file=/data/pve-storage/images/4016/vm-4016-disk-1.raw,if=none,id=drive-virtio1,aio=native,cache=none: could not open disk image /data/pve-storage/images/4016/vm-4016-disk-1.raw: Invalid argument

Install on a high performance system

As of 2013 high performance servers have 16-64 cores, 256GB-1TB RAM and potentially many 2.5" disks and/or a PCIe based SSD with half a million IOPS. High performance systems benefit from a number of custom settings, for example enabling compression typically improves performance.

• If you have a good number of disks keep organized by using aliases. Edit /etc/zfs/vdev_id.conf to prepare aliases for disk devices found in /dev/disk/by-id/ :

# run 'udevadm trigger' after updating this file
alias a0        scsi-36848f690e856b10018cdf39854055206
alias b0        scsi-36848f690e856b10018cdf3ce573fdeb6
alias a1        scsi-36848f690e856b10018cdf40f5b277cbc
alias b1        scsi-36848f690e856b10018cdf43a5db1b99b
alias a2        scsi-36848f690e856b10018cdf4575f652ad0
alias b2        scsi-36848f690e856b10018cdf47761587cec

Use flash for caching/logs. If you have only one SSD, use cfdisk to create a small partion for the ZIL (ZFS intent log) and a larger one for the L2ARC (ZFS read cache on disk). Make sure that the ZIL is on the first partition. In our case we have a Express Flash PCIe SSD with 175GB capacity and setup a ZIL with 25GB and a L2ARC cache partition of 150GB

• edit /etc/modprobe.d/zfs.conf​ to apply several tuning options for high performance servers:

# ZFS tuning for a proxmox machine that reserves 64GB for ZFS
#
# Don't let ZFS use less than 4GB and more than 64GB
options zfs zfs_arc_min=4294967296
options zfs zfs_arc_max=68719476736
#
# disabling prefetch is no longer required
options zfs l2arc_noprefetch=0

• create a zpool of striped mirrors (equivalent to RAID10) with log device and cache and always enable compression:

zpool create -o compression=on -f tank mirror a0 b0 mirror a1 b1 mirror a2 b2 log /dev/rssda1 cache /dev/rssda2​

• ​​​​​​​​check the status of the newly created pool:

root@proxmox:/# zpool status
  pool: tank
 state: ONLINE
  scan: none requested
config:

        NAME        STATE     READ WRITE CKSUM
        tank        ONLINE       0     0     0
          mirror-0  ONLINE       0     0     0
            a0      ONLINE       0     0     0
            b0      ONLINE       0     0     0
          mirror-1  ONLINE       0     0     0
            a1      ONLINE       0     0     0
            b1      ONLINE       0     0     0
          mirror-2  ONLINE       0     0     0
            a2      ONLINE       0     0     0
            b2      ONLINE       0     0     0
        logs
          rssda1    ONLINE       0     0     0
        cache
          rssda2    ONLINE       0     0     0

errors: No known data errors

Using PVE 2.3 on a 2013 high performance system with ZFS you can install Windows Server 2012 Datacenter Edition with GUI in just under 4 minutes.

zfs links and docs

• http://zfsonlinux.org/faq.html

• http://hub.opensolaris.org/bin/download/Community+Group+zfs/docs/zfslast.pdf

and this has some very important information to know before implementing zfs on a production system.

• http://www.solarisinternals.com/wiki/index.php/ZFS_Best_Practices_Guide

check these well written manual pages:

man zfs

man zpool

How to install ZFS-fuse under Proxmox

(Tested with Kernel 2.6.32)

 apt-get install build-essential libaio-dev libattr1-dev libacl1-dev libz-dev libz-dev libfuse-dev libfuse2 scons libssl-dev
 wget -nd http://zfs-fuse.net/releases/0.6.0/zfs-fuse-0.6.0.tar.bz2
 tar jxvf zfs-fuse-0.6.0.tar.bz2
 cd zfs-fuse-0.6.0
 cd src
 scons
 scond install

Note: zfs-fuse-0.6.0 is now (Dec 2012) deprecated. Use zfs-fuse-0.7.0.tar.bz2 instead.

Fire up ZFS-fuse daemon

 /usr/local/sbin/zfs-fuse

Create Zpool

 zpool create -m /var/lib/vz/images2 /dev/sdb

Create ZFS

 zfs create images2/109

ZFS clone a vm 109 to vm 110

 zfs snapshot images2/109@master
 zfs clone images2/109@master images2/110

Debian GNU/kFreeBSD

As of 2012-02 the squeeze version does not have NFS, so AFAIK can not be used for Proxmox storage. When Debsd has nfs support then I'd use this for storage of iso's and backups to start. In the mean time this works as a samba server..

zfs works much better using Debian/GNU kFreeBSD then fuse.

after installing the system to kvm or hardware:

• add some disks . in KVM i was only able to get ide to work.

• the scsi disks look like:

ls /dev/ad*
/dev/ad10  /dev/ad10s1  /dev/ad10s2  /dev/ad11  /dev/ad12  /dev/ad13

• per http://www.solarisinternals.com/wiki/index.php/ZFS_Best_Practices_Guide - if I read it right - use entire disk not slices for zfs (I assume slices = partitions).

• if the disks have partition tables, then clear them. just not the operating system disk! I used fdisk to clear the tables. This may not be necessary , if it is not then please delete this part.

fdisk /dev/ad11
o
w

then same for ad12 and ad13

• install this

aptitude install zfsutils

• make a pool

zpool create -f  zfs-pool /dev/ad11 /dev/ad12  /dev/ad13

df | grep zfs-pool
zfs-pool       zfs    1.4T   18K  1.4T   1% /zfs-pool

• http://wiki.debian.org/Debian_GNU/kFreeBSD