Dell

Dell Compellent and SCSI UNMAP

May 15, 2016 Bilal Ahmed 0

Dead space reclamation (SCSI UNMAP) Basically the UNMAP command is used when you have Thin Provisioned LUNs, you run it against VMFS  5 datastores, hopefully freeing up some space. This will allow the hosts to correctly report the list of deleted blocks on the datastore to the array. It basically is a space reclamation feature that helps reclaim space left by deleted data. The main reasons you would want to run this on all Thin Provisioned LUNs, would be because of: Storage vMotion, VM snapshots and VM deletion. As even though the VM/Snapshot etc has been deleted it doesn’t mean the array is aware of this! It was disabled in ESXi 5.0, due to various issues and enabled in 5.1 by using […]

Lost connectivity to the device mpx.vmhba32 ERROR

May 11, 2016 Bilal Ahmed 0

So I had this wonderful error happen to me recently. I am in the process of migrating the Management IPs from one network to another on all the hosts in the environment. It is part of a bigger plan to migrate everything including the vCenter components to a new IP range ( I am not looking forward to that esp since this is a 5.1 environment!). I did that and updated DNS, flushed the DNS caches on my machine and on the PRTG probes etc. The host came back up fine, but when it rejoined vCenter it had this wonderful error message: Lost connectivity to the device mpx.vmhba32:C0:T0:L0 backing the boot filesystem /vmfs/devices/disk/mpx.vmhba32:C0:T0:L0. As a result, host configuration changes will […]