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Deleting snapshots of virtual machines with heavy disk I/O might cause host to be disconnected from VirtualCenter (1003024)
When you delete one or more snapshots of a powered-on virtual machine which has big disks and is under heavy disk I/O activity, the snapshot deletion can take several hours. During this time, the host might be disconnected from the VirtualCenter Server.
The virtual machine's disks are write-locked during snapshot deletion. Any data written to the virtual machine disks is written to a temporary snapshot. The changes are committed to the disks when the deletion is complete and the locks are released. The disconnection of the host from VirtualCenter does not affect this commitment of data.
Upgrading to vCenter 2.5 Update 1 or later and ESX 3.5 Update 1 or later corrects this issue.
When the snapshot completes, the ESX host reconnects to vCenter automatically. For more information, see Command to monitor snapshot deletion in VMware ESX/ESXi (1007566).
See step 2 of Committing snapshots from within the Service Console (1006847) for information on determining if the virtual machine still has snapshots.
If the ESX does not reconnect after the completion of the snapshot deletion, see Restarting the Management agents on ESX Server (1003490) on how to manually restart the appropriate services.
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