I have a simple VMWare ESX Server 3 farm (plus Virtual Infrastructure/HA) that is running off of a single iSCSI SAN. We have a NetGear ReadyNAS 2100 set up as an iSCSI target with two volumes (mirroring the iSCSI SAN). Its job is to run as a backup should the primary fail and also as primary storage for some really large, non critical VMs.

I have successfully added it to my storage cluster except that both of the targets are somehow stuck in single host mode so only one of the hosts in the farm is attached to it (this differs from our primary storage where all hosts are connected to both targets).

How have I managed to mis-configure my vmware storage? I need both hosts to talk to this backup iSCSI to achieve my recovery goals.


2 Answers 2


I don't believe the ReadyNAS 2100 supports cluster (ie multiple concurrent host) access to iSCSI targets. This in not uncommon on entry level iSCSI h/w. That may be fixed in a firmware revision, best ask NETGEAR directly.

  • Strange, I re-added it to one of my hosts and now it shows up on BOTH hosts under VirtualCenter. Exciting and terrifying all at once! :D Jun 24, 2009 at 19:16
  • That's good to know - the NETGEAR support site doesn't have anything to say about it that I can find but the community forum seemed to indicate that multiple initiator connections to a single iSCSI volume was not available "at this time" - Can't link to the posts but if you go to readynas.com/forum/viewtopic - and search for cluster you'll see the thread.
    – Helvick
    Jun 24, 2009 at 19:40

Turns out that I can. Maybe it's a firmware thing that is new? I dunno. Anyway, I removed it from my hosts then re-added it:

 /usr/sbin/vmkiscsi-tool -D -a IPADDRESS vmhba40

 esxcfg-swiscsi -s

Then added it to each host via VirtualCenter. Now it shows as "Multiple Hosts" and I can create VMs on it! Huzzah!

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