Part of the current phase of the project involved replacing the Xstack with a Cybernetics miSAN D-12. We started the project running of a Dlink xstack that was repurposed from a different project. We did find that we could achieve link saturation when copying large VHD files if the xcopy command was executed from the newly added VM3 node.Īt first we thought it was hardware problems, but I can't believe that both of the first two nodes are having the same failure.

If it was part of the cluster, all other services on the cluster would go to saved-critical whenever a node would restart. It did not matter of that node was running any services (VMs) at that time or not. We went down to one switch on that net for the time being and performance improved, though we still never say NIC saturation when moving large amounts of data around the iscsi network.Īfter that, we found that we could also crash the cluster by rebooting one of the virtual hosts. We were running redundant switches on the iSCSI network between the hosts and the SAN, but one of them went flakey. The times of the cluster crashes seemed to coincide with operations that had a large amount of disk IO, like DPM doing VSS calls for a protection group that included the VHD files on the Cluster Shared Volumes. During a crash, all VMs go into a Saved-Critical state and the hosts report that they cant access the CSVs. Since we've added the 3rd node to the cluster, we have seen some odd crashes.

Last month, we starting our next phase of the project, which includes an upgrade for the SAN, the addition of a 3rd Virtual Host in the cluster, and the p2v of 8 more servers from the physical realm. We ran on this config for 6+ months without issue, except that we noticed on several occasions when coping large VHD files around the iscsi network, we noticed that transfers were taking a long time and the NIC utilization never went above 20%. We protected the entire cluster with Microsoft DPM that ran on a physical box with it's own SAN running JBOD. The 2 volumes were RAID 1 and RAID 5 and are used for storing the system and data drives separately. The SAN had 2 cluster shared volumes available on the iscsi network. The 2 virtual hosts are intel S5520UR server boards running on both processors. running off of a cluster shared volume on a Dlink SAN over a isolated iSCSI network. The initial role out had us virtualize two domain controllers, exchange, sql, and sharepoint. Our initial setup included a two node hyper-v cluster.

Cybernetics misan d setup