StorPool Integration with OpenNebula


The StorPool datastore driver enables OpenNebula to use a StorPool storage system for storing disk images.


To contribute bug patches or new features, you can use the github Pull Request model. It is assumed that code and documentation are contributed under the Apache License 2.0.

More info:



Details could be found in Support Life Cycles for OpenNebula Environments at the StorPool Knowledge Base.


OpenNebula Front-end

  • Working OpenNebula CLI interface with oneadmin account authorized to OpenNebula’s core with UID=0

  • Network access to the StorPool API management interface

  • StorPool CLI installed

  • Python3 installed

OpenNebula Node

  • StorPool initiator driver (storpool_block)

  • If the node is used as Bridge Node - the OpenNebula admin account oneadmin must be member of the ‘disk’ system group to have access to the StorPool block device during image create/import operations.

  • If it is Bridge Node only - it must be configured as host in OpenNebula but configured to not run VMs.

  • The Bridge node must have qemu-img available - used by the addon during imports to convert various source image formats to StorPool backed RAW images.

  • (Recommended) Installed qemu-kvm-ev package from centos-release-qemu-ev repository for CentOS7

Same requirements are applied for nodes that are used as Bridge nodes.

StorPool cluster

A working StorPool cluster is mandatory.


Standard OpenNebula datastore operations:

  • essential Datastore MAD(DATASTORE_MAD) and Transfer Manager MAD(TM_MAD) functionality (see limitations)

  • (optional) SYSTEM datastore volatile disks as StorPool block devices (see limitations)

  • SYSTEM datastore on shared filesystem or ssh when TM_MAD=storpool is used

  • SYSTEM datastore context image as a StorPool block device (see limitations)

  • support migration from one SYSTEM datastore to another if both are using storpool TM_MAD


  • delayed termination of non-persistent images: When a VM is terminated the corresponding StorPool volume is stored as a snapshot that is deleted permanently after predefined time period (default 48 hours)

  • support different StorPool clusters as separate datastores

  • support multiple OpenNebula instances in single StorPool cluster

  • import of VmWare (VMDK) images

  • import of Hyper-V (VHDX) images

  • partial SYSTEM datastore support (see limitations)

  • (optional) set limit on the number of VM disk snapshots (per disk limits)

  • (optional) helper tool to migrate CONTEXT iso image to StorPool backed volume (require SYSTEM_DS TM_MAD=storpool)

  • (optional) send volume snapshot to a remote StorPool cluster on image delete

  • (optional) alternate local kvm/deploy script that allows tweaks to the domain XML of the VMs with helper tools to enable iothreads, ioeventfd, fix virtio-scsi nqueues to match the number of VCPUs, set cpu-model, etc

  • (optional) support VM checkpoint file stored directly on a StorPool backed block device (see Limitations)

  • (optional) replace the “VM snapshot” interface scripts to do atomic disk snapshots on StorPool with option to set a limit on the number of snapshots per VM (see limitations)

  • (optional) replace the <devices/video> element in the domain XML

  • (optional) support for UEFI Normali/Secure boot with persistent UEFI nvram stored on StorPool backed block device

Following the OpenNebula Policy change introduced with OpenNebula 5.12+ addon-storpool do not patch opennebula files by default. Please contact OpenNebula support if you need any of the following items resolved.

  • (optional) patches for Sunstone to integrate addon-storpool to the Datastore Wizard. There is no known resolution beside patching and rebuilding the sunstone interface.


  1. OpenNebula has hard-coded definition of the volatile disks as type FILE in the VMs domain XML. Latest libvirt forbid the live migration without the --unsafe flag set. Generally enabling the --unsafe flag is not recommended so feature request OpenNebula/one#3245 was made to address the issue upstream.

  2. OpenNebula temporary keep the VM checkpoint file on the Host and then (optionally) transfer it to the storage. An workaround was added on the base of OpenNebula/one#3272.

  3. When SYSTEM datastore integration is enabled the reported free/used/total space of the Datastore is the space on StorPool. (On the host filesystem there are mostly symlinks and small files that do not require much disk space).

  4. VM snapshotting is not possible because it is handled internally by libvirt which does not support RAW disks. It is possible to reconfigure the ‘VM snapshot’ interface of OpenNebula to do atomic disk snapshots in a single StorPool transaction when only StorPool backed datastores are used.

  5. Tested only with KVM hypervisor and CentOS. Should work on other Linux OS.


The installation instructions are for OpenNebula 5.12+.

If you are upgrading addon-storpool please read the Upgrade notes first!


front-end dependencies

# CentOS 7 front-end
yum -y install --enablerepo=epel jq xmlstarlet nmap-ncat pigz tar xmllint python36-lxml
# AlmaLinux 8 front-end
dnf -y install --enablerepo=epel jq xmlstarlet nmap-ncat pigz tar libxml2 python3-lxml
# Ubuntu 22.04 front-end
apt -y install tar jq xmlstarlet netcat pigz python3-lxml libxml2-utils

node dependencies


use when adding new hosts too

# CentOS 7 node-kvm
yum -y install --enablerepo=epel jq pigz python36-lxml xmlstarlet tar
# AlmaLinux 8 node-kvm
dnf -y install --enablerepo=epel jq pigz python3-lxml xmlstarlet tar
# Ubuntu 22.04 node-kvm
apt -y install jq xmlstarlet pigz python3-lxml libxml2-utils tar

Get the addon from github

cd ~
git clone

automated installation

The automated installation is best suitable for new deployments. The install script will try to do an upgrade if it detects that addon-storpool is already installed but it is possible to have errors due to non expected changes

If oned and sunstone services are on different servers it is possible to install only part of the integration:

  • set environment variable AUTOCONF=1 to enable the automatic configuration of addon defaults in the opennebula config

  • Run the install script as ‘root’ user and check for any reported errors or warnings

cd addon-storpool
bash 2>&1 | tee install.log

manual installation

The following commands are related to latest Stable version of OpenNebula.

addon-storpool configuration

The global configuration of addon-storpool is in /var/lib/one/remotes/addon-storpoolrc file.

  • Edit /etc/one/oned.conf and add storpool to the TM_MAD arguments

TM_MAD = [
    executable = "one_tm",
    arguments = "-t 15 -d dummy,lvm,shared,fs_lvm,qcow2,ssh,vmfs,ceph,dev,storpool"
  • Edit /etc/one/oned.conf and add storpool to the DATASTORE_MAD arguments

    executable = "one_datastore",
    arguments  = "-t 15 -d dummy,fs,vmfs,lvm,ceph,dev,storpool  -s shared,ssh,ceph,fs_lvm,qcow2,storpool"
  • When storpool backed SYSTEM datastore is used, edit /etc/one/oned.conf and update the ARGUMENTS of the VM_MAD for KVM to enable the deploy-tweaks script.

 VM_MAD = [
     NAME           = "kvm",
     EXECUTABLE     = "one_vmm_exec",
     ARGUMENTS      = "-l deploy=deploy-tweaks -t 15 -r 0 kvm",

Optionally add attach_disk,tmsave/tmrestore:
VM_MAD = [
    NAME           = "kvm",
    EXECUTABLE     = "one_vmm_exec",
    ARGUMENTS      = "-l deploy=deploy-tweaks,attach_disk=attach_disk.storpool,save=tmsave,restore=tmrestore -t 15 -r 0 kvm",
  • Edit /etc/one/oned.conf and append TM_MAD_CONF definition for StorPool

  • Edit /etc/one/oned.conf and append DS_MAD_CONF definition for StorPool

  • Edit /etc/one/oned.conf and append the following _VM_RESTRICTEDATTR

cat >>/etc/one/oned.conf <<_EOF_
  • Enable live disk snapshots support for StorPool by adding kvm-storpool to LIVE_DISK_SNAPSHOTS variable in /etc/one/vmm_exec/vmm_execrc

LIVE_DISK_SNAPSHOTS="kvm-qcow2 kvm-ceph kvm-storpool"

The addon will try to autodetect the leader IP address from oned configuration but if it fail set it manually in addon-storpoolrc

echo "RAFT_LEADER_IP=" >> /var/lib/one/remotes/addon-storpoolrc

OpenNebula 6.0 introduces changes in the Image import function

For OpenNebula up to 5.12.*(included):

echo "DS_CP_REPORT_FORMAT=0" >> /var/lib/one/remotes/addon-storpoolrc

For OpenNebula 6+:

echo "DS_CP_REPORT_FORMAT=1" >> /var/lib/one/remotes/addon-storpoolrc
  • If you plan to do live disk snapshots with fsfreeze via qemu-guest-agent but SCRIPTS_REMOTE_DIR is not the default one (if it is changed in /etc/one/oned.conf), define SCRIPTS_REMOTE_DIR in the addon global configuration.


  • Restart opennebula service

systemctl restart opennebula
  • As oneadmin user (re)sync the remote scripts to the hosts

su - oneadmin -c 'onehost sync --force'
  • Add oneadmin user to the mysyslog group if available

grep -q mysyslog /etc/group && usermod -a -G mysyslog oneadmin

OpenNebula Configuration

Make sure that the OpenNebula shell tools are working without additional arguments. When OpenNebula endpoint differ from default one eider create ~oneadmin/.one/one_endpoint file or set ONE_XMLRPC in addon-storpoolrc.

Configuring hosts

StorPool uses resource separation utilizing the cgroup subsystem. The reserved resources should be updated in the ‘Overcommitment’ section on each host (RESERVED_CPU and RESERVED_MEM in pre ONE-5.4). There is a helper script that report the values that should be set on each host. The script should be available after a host is added to OpenNebula.

# for each host do as oneadmin user
ssh hostN /var/tmp/one/ >reserved.tmpl
onehost update 'hostN' --append reserved.tmpl

Please note that the ‘Overcommitment’ change has no effect when NUMA configuration is used for the VMs

Configuring the System Datastore

addon-storpool is doing its best to support transfer manager (TM_MAD) backend of type shared, ssh, or storpool (recommended) for the SYSTEM datastore. When only StorPool Storage is used the SYSTEM datastore will hold only symbolic links to the StorPool block devices, so it will not take much space. See more details on the Open Cloud Storage Setup.

  • By default the storpool TM_MAD is with enabled SHARED attribute (SHARED=YES). But the default behavior for SYSTEM datastores is to use ssh. If a SYSTEM datastore is on shared filesystem then SP_SYSTEM=shared should be set in the datastore configuration

Configuring the Datastore

Some configuration attributes must be set to enable a datastore as StorPool enabled one:

  • DS_MAD: [mandatory] The DS driver for the datastore. String, use value storpool

  • TM_MAD: [mandatory] Transfer driver for the datastore. String, use value storpool

  • DISK_TYPE: [mandatory for IMAGE datastores] Type for the VM disks using images from this datastore. String, use value block

  • BRIDGE_LIST: Nodes to use for image datastore operations. String (1)

  1. Quoted, space separated list of server hostnames which are members of the StorPool cluster. If it is left empty or removed the front-end must have working storpool_block service (must have access to the storpool cluster) as all disk preparations will be done locally.

After a datastore is created in OpenNebula a StorPool template must be created to represent the datastore in StorPool. The name of the template should be one-ds-${DATASTORE_ID} where ${DATASTORE_ID} is the ID of the OpenNebula’s Datastore. Please refer the StorPool’s User Guide for details how to configure a StorPool template.

  • When there are multiple OpenNebula instances using same StorPool cluster a custom prefix should be set for each opennebula instance in the addon-storpoolrc configuration file

The following example illustrates the creation of a StorPool datastore. The datastore will use hosts node1, node2 and node3 for importing and creating images.

Image datastore through Sunstone

Sunstone -> Storage -> Datastores -> Add [+]

  • Name: StorPool IMAGE

  • Storage Backend: Custom

    Drivers (Datastore): Custom -> Custom DS_MAD: storpool Drivers (Transfer): Custom -> Custom TM_MAD: storpool

  • Datastore Type: Images

  • Disk type -> Block

  • Host Bridge List: node1 node2 node3

Image datastore through onedatastore

# create datastore configuration file
$ cat >/tmp/imageds.tmpl <<EOF
NAME = "StorPool IMAGE"
DS_MAD = "storpool"
TM_MAD = "storpool"
DISK_TYPE = "block"
BRIDGE_LIST = "node1 node2 node3"

# Create datastore
$ onedatastore create /tmp/imageds.tmpl

# Verify datastore is created
$ onedatastore list

  ID NAME                SIZE AVAIL CLUSTER      IMAGES TYPE DS       TM
   0 system             98.3G 93%   -                 0 sys  -        ssh
   1 default            98.3G 93%   -                 0 img  fs       ssh
   2 files              98.3G 93%   -                 0 fil  fs       ssh
 100 StorPool            2.4T 99%   -                 0 img  storpool storpool

Create a StorPool template for the datastore with ID 100:

storpool template one-ds-100 replication 3 placeHead hdd placeAll hdd placeTail ssd

System datastore through Sunstone

Sunstone -> Datastores -> Add [+]

  • Name: StorPool SYSTEM

  • Storage Backend: Custom

    Drivers (Transfer): Custom -> Custom TM_MAD: storpool

  • Datastore Type: System

  • Host Bridge List: node1 node2 node3

System datastore through onedatastore

# create datastore configuration file
$ cat >/tmp/ds.conf <<_EOF_
NAME = "StorPool SYSTEM"
TM_MAD = "storpool"

# Create datastore
$ onedatastore create /tmp/ds.conf

# Verify datastore is created
$ onedatastore list

  ID NAME                SIZE AVAIL CLUSTER      IMAGES TYPE DS       TM
   0 system             98.3G 93%   -                 0 sys  -        shared
   1 default            98.3G 93%   -                 0 img  fs       shared
   2 files              98.3G 93%   -                 0 fil  fs       ssh
 100 StorPool            2.4T 99%   -                 0 img  storpool storpool
 101 StorPoolSys           0M -     -                 0 sys  -        storpool

Create a StorPool template for the datastore with ID 101:

storpool template one-ds-101 replication 3 placeHead hdd placeAll hdd placeTail ssd

Advanced addon configuration

Please follow the advanced configuration guide to enable the extras that are not covered by the basic configuration.

Configuration tips

Please follow the configuration tips for suggestions how to optionally reconfigure OpenNebula.

Upgrade notes

  • The suggested upgrade procedure is as follow

    1. Stop all opennebula services

    2. Upgrade the opennebula packages. But do not reconfigure anything yet

    3. Upgrade the addon (checkout/clone latest from github and run AUTOCONF=1 bash

    4. Follow the addon configuration chapter in to (re)configure the extras

    5. Continue (re)configuring OpenNebula following the upstream docs

StorPool naming convention

Please follow the naming convention for details on how the OpenNebula’s datastores and images are mapped to the StorPool Templates, Volumes and Snapshots.

Known issues

  • In release 19.03.2 the volume names of the attached CDROM images was changed. A separate volume with a unique name is created for each attachment. This could lead to errors when using restore with the alternate VM snapshot interface enabled. The workaround is to manually create/or rename/ a snapshot of the desired CDROM volume following the new naming convention. The migration to the new CDROM’s volume naming convention is integrated so there is no manual operations needed.

  • Recent version of libvirt has more strict checks of the domain xml and do not allow live migration when there are file backed VM disks that are not on shared filesystem. The definition of the volatile disks that OpenNebula create are with hard-coded type ‘file’ that conflict with libvirt. There is a fix for this in addon-storpool 19.04.3+ but it will not alter the currently running VM’s. A workaround is to patch vmm/kvm/migrate and add a check that enable --unsafe option if all disks are with disabled cache (cache="none"). The following line just before the line that do the VM migration could leverage this issue:

(virsh --connect $LIBVIRT_URI dumpxml $deploy_id 2>/dev/null || echo '<a><disk device="disk"><driver cache="writeback"/></disk></a>') | xmllint --xpath '(//disk[@device="disk"]/driver[not(@cache="none")])' - >/dev/null 2>&1 || MIGRATE_OPTIONS+=" --unsafe"