[Pkg-iscsi-maintainers] Bug#632275: iscsid: configured replacement_timeout is ignored

[Jim Paris]

Ritesh Raj Sarraf wrote:
> On 07/01/2011 11:22 AM, Jim Paris wrote:
> > I have root on iscsi, so the connection already exists by the time
> > iscsid starts.  Regardless of the value of
> > node.session.timeo.replacement_timeout in my /etc/iscsi/iscsid.conf,
> > iscsid prints:
> >
> >   iscsid: Cannot set replacement_timeout to zero. Setting 120 seconds
> >
> > and I see:
> >
> >   # cat /sys/class/iscsi_session/session1/recovery_tmo 
> >   120
> >
> 
> This is intentional. Why are you setting it to 0?
>
> The default is set to 120 seconds so that consumers of iSCSI that do not
> use an upper stack like multipath still have a 2 minute window before
> SCSI gives up.

I'm not setting it to 0!  I definitely don't want it to be zero.  The
only thing in my /etc/iscsi/iscsi.conf (as you can see attached in
this bugreport) is:

  node.session.timeo.replacement_timeout = 31536000

> If you want quick results, use a sane value like 5 seconds. That's what
> I recommend to my users. 0 just does not make sense.

I don't want it to ever time out.  120 seconds is too short.

> > If I change it manually, and restart iscsid, it still gets reset:
> >
> >   # echo 31536000 > /sys/class/iscsi_session/session1/recovery_tmo
> >   # cat /sys/class/iscsi_session/session1/recovery_tmo 
> >   31536000
> >   # killall iscsid
> >   # iscsid
> >   # cat /sys/class/iscsi_session/session1/recovery_tmo 
> >   120
>
> Which is correct because the iscsi node database will have set the
> default value (120 secs) when doing the discovery. If you want that
> changed, change it to 5 in iscsid.conf and do a rediscovery.

But it's already 31536000 in iscsid.conf!

> > Which makes things very unhappy if the network ever gets disconnected
> > for a few minutes.
>
> If you are using SAN, you better have a good network. But that can't be
> guaranteed. That is why we have Device Mapper Multipath. With
> dm-multipath (and its queue_if_no_path feature), you can tackle this
> scenario very easily.

I don't need a perfect network -- this is just my one desktop machine
on my home network.  If the network disappears, I just want I/O to
hang until it comes back.  If dm-multipath can be shoehorned into the
Debian root-on-iscsi iscsi support, that might help me.  But either
way, iscsid isn't letting me set the timeout.

> >   iscsid -f -d 8 
> No. like I mentioned, it takes those values from the node database.
> 
> 
> I don't see this as a bug at all. But I'd want you to close it if you
> have no questions further.
> 

Thanks,
-jim