iSCSI on XCP-ng - XCP-ng-Specific Considerations

XCP-ng Overview

Key Characteristics:

• Open-source hypervisor based on Xen, forked from XenServer

• CentOS/RHEL-based dom0 (uses yum package manager)

• Uses XAPI (Xen API) and SMAPI (Storage Management API) for storage

• Managed via Xen Orchestra (web UI) or xe CLI

• Uses Open vSwitch for networking by default

Recommended Versions:

• XCP-ng: 8.3

• Kernel: XCP-ng default kernel (includes required iSCSI and multipath modules)

Package Management

Update system:

# Update package lists and upgrade
yum update -y

Essential packages (pre-installed on XCP-ng):

# Core iSCSI and multipath tools are pre-installed
rpm -qa | grep iscsi-initiator-utils
rpm -qa | grep device-mapper-multipath

Verify installation:

# Check iSCSI initiator
iscsiadm --version

# Check multipath
multipath -ll

# Check services
systemctl status iscsid
systemctl status multipathd

XCP-ng Storage Architecture

XCP-ng uses Storage Repositories (SR) to manage storage:

• lvmoiscsi: LVM over iSCSI driver (recommended for iSCSI)

• SR: Storage Repository - collection of VDIs (Virtual Disk Images)

• VDI: Virtual Disk Image - individual VM disk

• PBD: Physical Block Device - connection between host and SR

# List SRs
xe sr-list

# List PBDs
xe pbd-list

# Get SR details
xe sr-param-list uuid=<SR_UUID>