iSCSI Multiple Connected Sessions in 9.3

[Lorsung23647]

I can't seem to find an option to allow for multiple connected iSCSI sessions in 9.3. I'm guessing that this was something that went away with the change to CTL, but I figured that I should make sure.

So did multiple sessions leave us in 9.3, or can I not find the setting?

Also, if they did depart, will they ever return to us?

 

[jgreco]

What option was there to "allow" this?

Pretty much by definition, iSCSI allows multiple connected sessions. The usual problem is PEBCAK with users placing a non-cluster-aware filesystem like NTFS on top of an iSCSI disk and then trying to attach to it from two different initiators. This, of course, is "bad" in that the NTFS will become corrupted very quickly, but it works just fine if you look at it strictly at the disk abstraction level.

Is it not letting you do this?

 

[Lorsung23647]

In the Target Global Configuration, this option used to exist:

Max. Connections - The number of connections a single initiator can make to a single target; values range from 1-65536 with a default of 8

With the default setting, if I opened my target properties in Windows, it would show Maximum Allowed Connections: 8

After the upgrade, the Max. Connections option doesn't exist, or I can't find it, and my Maximum Allowed Connections shows as 1.


I also looked at how my ESXi hosts are doing, and they are still running multipath, and my datastores changed from non-ssd to ssd?


So basically, my ESXi hosts are unaffected by this, they still have their multiple sessions running. Windows thinks that it can only connect 1 time, and refuses to connect a second time.

 

[jgreco]

Interesting. I haven't actually seen 9.3. In any case, you weren't particularly clear what you were talking about because it looks like that's intended to restrict the number of times a single initiator attaches. I'd sugggest you post a bug report on it and be clear about what you mean.

Also I got called "whiny" by the CTO of iX for complaining about the SSD thing, so "don't complain about that."

 

[Lorsung23647]

Basically, for my Windows host, I can only connect one session to each target, whereas I used to be able to connect multiple. The option to configure the Maximum Connections doesn't seem to exist in 9.3 either.

And I'm not complaining about the SSD thing, just kind of a, "well, ok then" moment.

 

[mav@]

New iSCSI implementation indeed does not support multiple connection per session (MC/S) at this time. If you want to get MPIO iSCSI, you may install respective Windows component (AFAIK only in Windows Server 2008/2012) and establish several sessions, checking "Enable multipath" checkbox for each one. After that Windows should identify that same LUN is accessible through several paths, aggregate them, and give effect close to MC/S.

 

[apple4ever]

Also I got called "whiny" by the CTO of iX for complaining about the SSD thing, so "don't complain about that."

Wow really? Its not whining to complain about something that is not working right. Its a bug that it reports as SSD, and vSphere may behave differently when it sees that.

I've also run into the issue where multiple ESXi hosts can't see the same datastore- thought for some reason its not all of them.