Sharing a LUN

[rvent]

Hello,

I would like to know if and how i can share a LUN between servers...?

Let me explain what i would like to accomplish: I've had good success using Linux-HA+DRBD to cluster services like, mail, mySQL, apache, etc; with this the data was replicated to the second node using DRBD.

Now i have an EVA4400, 4 blades and XenServer Enterprise. I would like to be able to acheive the same result. I would like to be able to have 2 VMs use a LUN with a cluster FS to be able to access data on both VMs. I wouldnt need to make use of DRBD since the drive wouldnt need to be replicated so i would just need to configure Linux-HA.

Someone on the citrix forums mentioned i can accomplish this by using iSCSI, but how can i create iSCSI disks using the EVA4400?

Thanks

[Uwe Zessin · Accepted solution]

Just present the virtual disk to multiple servers, it doesn't matter if it's via FC or iSCSI - now the disk is 'shared'!
... at the block level as the EVA does not know what a file is. You have alread mentioned the magic words "cluster FS", so I guess you know what you are doing ;-)

The EVA-4400 is a native Fibre Channel array, but you can connect gateway boxes (FC/iSCSI converts) to the host ports or to Fibre Channel switches if you run mixed FC/iSCSI hosts.

[rvent]

Yes, thank you. Unfortunately i was hoping to be able to use it with the VMs, but the only way i can think of doing it is by using iSCSI, else the LUN will be presented to the physical level and not the virtual level.

If i didnt have VMs i could simply do what you suggested.

Thanks

[Uwe Zessin]

Yes, agree. There was a similar question in a different thread whether it is possible to map Fibre Channel LUNs to VMs. I did a little internet search and it seams that XEN on SUSE Linux can do that with the help of NPIV, but I could not find out whether XenServer has that feature, too.