On Tuesday, June 30, 2020 at 6:00:03 AM UTC-7, Amit Bawer wrote:
>
> [Sorry if this message is duplicated, haven't seen it is published in the 
> group]
>
> Hi,
>
> Have couple of question regarding iscsiadm version 6.2.0.878-2:
>
> 1) Is it safe to have concurrent logins to the same target from different 
> interfaces? 
> That is, running the following commands in parallel:
>
> iscsiadm -m node -T iqn.2003-01.org.vm-18-198.iqn2 -I default -p 
> 10.35.18.121:3260,1 -l
> iscsiadm -m node -T iqn.2003-01.org.vm-18-198.iqn2 -I default -p 
> 10.35.18.166:3260,1 -l
>
> 2) Is there a particular reason for the default values of  
> node.conn[0].timeo.login_timeout and node.session.initial_login_retry_max?
> According to comment in iscsid.conf it would spend 120 seconds in case of 
> an unreachable interface login:
>
> # The default node.session.initial_login_retry_max is 8 and
> # node.conn[0].timeo.login_timeout is 15 so we have:
> #
> # node.conn[0].timeo.login_timeout * node.session.initial_login_retry_max 
> =
> #                                                               120 seconds
>
>
> Thanks,
> Amit
>

No, iscsiadm is not designed for parallel use. There is some locking, but 
IIRC there are still issues, like a single connection to the kernel?

After discovery, you should have NODE entries for each path, and you can 
login to both with "iscsiadm -m node -l".

As far as the default timeouts and retry counts are of course trade-offs. 
In general, iscsi can have flakey connections, since it's at the mercy of 
the network. In the event of a transient event, like a switch or target 
rebooting, the design allows reconnecting if and when the target finally 
comes back up, since giving up generally can mean data corruption (e.g. for 
a filesystem).

As the README for open-iscsi describes, you must tweak some of those 
numbers if you want to use multipathing, since the requirements for one of 
many paths usually requires a faster timeout, for example.

-- 
You received this message because you are subscribed to the Google Groups 
"open-iscsi" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To view this discussion on the web visit 
https://groups.google.com/d/msgid/open-iscsi/a179f9d6-05e1-4a08-bf3c-aebb23d59afdo%40googlegroups.com.

Reply via email to