VMFS6 and Auto-reclaim with Dell Compellent

[jedijeff]

I am trying to see if there is anyone with Dell Compellent (SCOS v7x) that is successfully seeing Auto-Reclaim work against a VMFS6 volume.

The HCL says that Dell Compellent with v7.x SCOS code will support auto-reclamation of VMFS6 volumes.

I am not seeing that happen though. Even after about 5 days of monitoring and testing by creating or cloning VMs on VMFS6 and then deleting them. I see no VAAI commands being issued in estop after days. I cannot really find anything in any logs that states its not working.

A theory right now is that Dell Compellent default 2MB data page size is being used and Unmap granularity, in which case it will not work at all.

However, Dell Compellent with v7.x SCOS is supported on the VMware HCL, which is the strange part to me. No where does it say anything about the page size.

[mhampto]

Take a look at Monitoring VMware vSphere Storage APIs – Array Integration using esxtop and maintaining the status a...  to see if the VAAI commands are running and performing the expected operations.

[dcfast201110141]

The maximum size currently for VMFS 6 UNMAP granularity is 1MB.  You are correct, the default data page size is 2MB in SCOS.  To be able to use the VMFS 6 auto-unmap capabilities, on the Storage Center, you'd need to create a "Storage Type" with a Data Page Size of 512KB and then create volumes from that 512KB Storage Type.