Live Migration of Guest Domains

Live migration lets you move a running guest domain from one SPARC server to another with minimal downtime. It is powerful for maintenance, load balancing and hardware replacement – but requires careful planning.

Requirements for live migration

Shared storage

Domain root and data disks must be on shared storage visible on both hosts.

Compatible hosts

CPU features, firmware and LDOMs versions must be compatible.

Checklist

Same or compatible CPU type and firmware on both hosts.
LDOMs Manager version compatible.
Domain disks on shared storage.
Network connectivity between hosts for migration traffic.

Commands: dry-run and live migration

1. Pre-check: same shared storage for root and data

Live migration usually requires shared storage visible to both hosts.

terminal — live migration

ldoms-lab

# Example: SAN LUNs or shared ZFS (via cluster/storage)
[root@hostA ~]# zpool status
[root@hostB ~]# zpool status
 
# Ensure domain's disks are on shared pool/LUNs

2. Dry-run migration

Use -n to validate that migration is possible between source and target.

terminal — live migration

ldoms-lab

[root@hostA ~]# ldm migrate -n ldg1 hostB
Initiating migration of LDom 'ldg1' to 'hostB'
Checking constraints and compatibility...
Migration check: PASSED

3. Perform live migration

Without -n, migration actually happens. Domain stays running with short pause.

terminal — live migration

ldoms-lab

[root@hostA ~]# ldm migrate ldg1 hostB
Initiating migration of LDom 'ldg1' to 'hostB'
LDom ldg1 successfully migrated
 
# After migration, domain is active on hostB:
[root@hostB ~]# ldm list ldg1
NAME    STATE    FLAGS  CONS  VCPU  MEMORY   UTIL  UPTIME
ldg1    active   -t---- 5000  4     8G       10%   5d

Important notes

Always test migration with non-critical domains first.
For DB / critical apps, coordinate with application team and monitor closely.
Ensure you have a rollback plan (domain can still run on source host if migration fails).