This post is a feature request for vSAN 🙂 One of my customers has a 4-nodes vSAN all-flash cluster. They use compression, deduplication and RAID 5 for non-critical VMs/vmdk and RAID 1 for critical. RAID 5 erasure coding requires less additional capacity to protect data than RAID 1 mirroring.
When you have vSAN enabled and you want to place the host in maintenance mode you have to choose one of the below options:
- Ensure accessibility
- Full data migration
- No data migration
My customer is not able to choose Full data migration because RAID 5 requires at least 4 hosts to be not in maintenance mode. This behaviour is correct. The 5th host requires additional license and hardware 😉
However, it would be a useful feature to have a possibility to choose and see which VMs can be still in compliance with a storage policy and accept or deny it. VMs on RAID 1 could be still in compliance but RAID 5 not (this would be accepted by my customer).
Simply put, Granular vSAN Maintenance Mode- e.g. Full data migration for RAID 1 and Ensure accessibility for RAID 5 - at the same time.
