Celerra on sigtar.com

Celerra - Unable to create, refresh, or delete checkpoint of a replicated destination file system

Tue, 09 Nov 2010 00:00:00 +1300

I’ve been stuck with this error recently on a Celerra manager device : DpRequest_Max_VS_SuspendedCheckpointsReached

This can sometimes happen when a filesystem is held during a replication task. To check what filesystems are currently being replcated run the following command;

nas_replicate -info -all

Either wait until the replication has completed - check status. Or temporary stop the replication task (stop it from the source side if possible).

EMC Celerra Optimizations for VMware on NFS

Tue, 12 Oct 2010 00:00:00 +1300

go here http://blog.scottlowe.org/2010/01/31/emc-celerra-optimizations-for-vmware-on-nfs/

Turn on the uncached write mechanism for NFS file systems used as VMware datastores. This can have a significant performance improvement for VMDKs on NFS but isn’t the default setting. From the Control Station, you can use this command to turn on the uncached write mechanism: server_mount <data mover name> -option <options>,**uncached** <file system name> <mount point> Be sure to review pages 99 through 101 of the VMware on Celerra best practices document for more information on the uncached write mechanism and any considerations for its use.

monitoring changed blocks (CBT) for replication of vmware virtual machines

Tue, 17 Aug 2010 00:00:00 +1200

Check this link for a great script to monitor changes made to a virtual machine via the vmware CBT API. This is perfect for finding culprit machines that are generating a lot of replication traffic if you are replicating over a WAN.

http://www.vmguru.com/index.php/articles-mainmenu-62/scripting/105-using-powershell-to-track-block-change-sizes-over-time

If you have some disks on a virtual machine you don’t want this script to capture then just set them as independent disks (so no snapshots can take place). This is handy if you have your windows page file on a separate disk that you don’t want to be measured as a part of the CBT changes.