Storage: ZFS over ISCSI

Storage pool type: zfs

This backend accesses a remote machine having a ZFS pool as storage and an iSCSI target implementation via ssh. For each guest disk it creates a ZVOL and, exports it as iSCSI LUN. This LUN is used by Proxmox VE for the guest disk.

The following iSCSI target implementations are supported:

• LIO (Linux)

• IET (Linux)

• ISTGT (FreeBSD)

• Comstar (Solaris)

This plugin needs a ZFS capable remote storage appliance, you cannot use it to create a ZFS Pool on a regular Storage Appliance/SAN

Configuration

In order to use the ZFS over iSCSI plugin you need to configure the remote machine (target) to accept ssh connections from the Proxmox VE node. Proxmox VE connects to the target for creating the ZVOLs and exporting them via iSCSI. Authentication is done through a ssh-key (without password protection) stored in /etc/pve/priv/zfs/<target_ip>_id_rsa

The following steps create a ssh-key and distribute it to the storage machine with IP 192.0.2.1:

mkdir /etc/pve/priv/zfs
ssh-keygen -f /etc/pve/priv/zfs/192.0.2.1_id_rsa
ssh-copy-id -i /etc/pve/priv/zfs/192.0.2.1_id_rsa.pub root@192.0.2.1
ssh -i /etc/pve/priv/zfs/192.0.2.1_id_rsa root@192.0.2.1

The backend supports the common storage properties content, nodes, disable, and the following ZFS over ISCSI specific properties:

pool

The ZFS pool/filesystem on the iSCSI target. All allocations are done within that pool.

portal

iSCSI portal (IP or DNS name with optional port).

target

iSCSI target.

iscsiprovider

The iSCSI target implementation used on the remote machine

comstar_tg

target group for comstar views.

comstar_hg

host group for comstar views.

lio_tpg

target portal group for Linux LIO targets

nowritecache

disable write caching on the target

blocksize

Set ZFS blocksize parameter.

sparse

Use ZFS thin-provisioning. A sparse volume is a volume whose reservation is not equal to the volume size.

Configuration Examples (/etc/pve/storage.cfg)

zfs: lio
   blocksize 4k
   iscsiprovider LIO
   pool tank
   portal 192.0.2.111
   target iqn.2003-01.org.linux-iscsi.lio.x8664:sn.xxxxxxxxxxxx
   content images
   lio_tpg tpg1
   sparse 1

zfs: solaris
   blocksize 4k
   target iqn.2010-08.org.illumos:02:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx:tank1
   pool tank
   iscsiprovider comstar
   portal 192.0.2.112
   content images

zfs: freebsd
   blocksize 4k
   target iqn.2007-09.jp.ne.peach.istgt:tank1
   pool tank
   iscsiprovider istgt
   portal 192.0.2.113
   content images

zfs: iet
   blocksize 4k
   target iqn.2001-04.com.example:tank1
   pool tank
   iscsiprovider iet
   portal 192.0.2.114
   content images

Storage Features

The ZFS over iSCSI plugin provides a shared storage, which is capable of snapshots. You need to make sure that the ZFS appliance does not become a single point of failure in your deployment.

Table 1. Storage features for backend iscsi

Content types	Image formats	Shared	Snapshots	Clones
images	raw	yes	yes	no

See Also

• Legacy: ZFS over iSCSI