xcp-ng-xapi-storage

Important: Drivers and libraries were forked from the Citrix open source packages of SMAPIv3 (before it was closed source). The original code was forked from xapi-storage-plugins-1.6.0-1.x86_64.rpm (LGPL) in XenServer 7.5.

Plugins to manage xapi storage datapaths

These plugins dictate how a storage volumes (local files, local block devices, iSCSI LUNs, Ceph RBD devices etc etc) should be mapped to Virtual Machines running on Xen.

The xapi storage interface describes the concepts, features and APIs in more detail.

Datapath plugins are named by URI schemes. Internally we have the following low-level implementations. These should not be referenced directly by Volume plugins:

• qdisk: opens a file with qemu-dp.
• tapdisk: opens a file with tapdisk and then tapdisk serves the VM directly using the user-space grant-table and grant-mapping code.

Build & installation

Install dependencies: cmake3, make, python-setuptools, nbd, python-psutil, qemu-dp, systemd and xapi-storage.

Run these commands in the project directory:

mkdir build
cd build
cmake3 .. -DCMAKE_INSTALL_PREFIX=/usr
make install

Do not forget to start qemuback service after installation:

systemctl daemon-reload
systemctl start qemuback.service

Issues and solutions

Important note: xapi-storage-script uses inotify to monitor plugins, so never delete /usr/libexec/xapi-storage-script/datapath/ or /usr/libexec/xapi-storage-script/volume/ folders!

I can't create SRs or plugins are not found.

Ensure you have installed the same xcp-ng-xapi-storage package in all hosts of your pool.

I can't start my VM with SMAPIv3 disks.

xapi-storage-script and qemuback services must be started to start correctly VMs.

You can check it with:

systemctl status xapi-storage-script.service
systemctl status qemuback.service