We have a Dell Storage SC9000 array installed by Dell reps mostly for hosting storage for VMware vCenter 6.5.
However I recently attempted to configure some Citrix XenServer 7.x servers and the array would not even let me talk to it over iSCSI. I eventually gave up and switched my server host hardware to VMware ESXi 6.5
Another colleague of mine attempted to integrate some Mac hardware using ATTO's iSCSI initiator was able to connect but would see the LUNs assigned but would also see a twin for each drive as well.
Was wondering if the Compellent was optimized just for VMware?
It should work fine for XenServer. I know I connected many of them over the years. The "twin" LUNs are showing up because there are multiple paths between the initiator and the target. Typically the initiator software has an option to configure the identity string to look for when combining multiple paths into a single logical volume.
I have an SC9000 on SCOS 7.2.11, and the latest version of DSM (DSM2016r3.20) and when you create a server object it has XENServer 7.x & 6.0, you should be able to connect to that cluster. As far as the ATTO, Dell does not test those, so for that you may need to speak with ATTO.
The admin in charge of the Compellent did that for XenServer but it doesn't see the XenServer hosts for some reason. I can only sometimes detect the array in the XenServer connection wizard and sometimes not and I can never fully connect to the LUN. The old Dell Equallogic array is on the same iSCSI network as the Compellent and it works just fine.
ATTO for some odd reason refuses to help.
I reached out to Studio Network Solutions who offers their own iSCSI initiator and they've been gracious enough to offer some advice. I'm convinced Dell didn't configure something properly with the array when they first installed it.
Have you looked over the Citrix XenServer with Dell SC Series Storage Configuration and Deployment Guide:
Refer to page 34 on Xen Storage for iSCSI HBA or page 13 for Open-iSCSI initiator
I wanted to come back to this as one of my co-workers ran into an ISCSI issue with XEN, we don't see a whole lot of XEN so when he was telling me about it I thought of this post.
There are a couple things to try out:
1) There are a couple of hot fixes listed in the bottom of this thread, some have said this has fixed the issue: https://bugs.xenserver.org/browse/XSO-678
2) See the 5th comment on the following link, it is a manual comment that needs to be made in a config file which solved the ISCSI issues this customer was seeing. Essentially by commenting out that sock.send line removes 1 extra byte that is causing errors. It appears both Xen and Dell are addressing this issue in future releases of SCOS and XEN. https://discussions.citrix.com/topic/384576-scan-target-fails-on-xenserver-7-and-compellent-sc9000/