[Stgt-devel] disk kicked out of RAID -> tgtd segmentation fault

[FUJITA Tomonori]

On Wed, 09 Jul 2008 10:16:41 +0200
Tomasz Chmielewski <mangoo at wpkg.org> wrote:

> FUJITA Tomonori schrieb:
> > On Wed, 09 Jul 2008 08:36:32 +0200
> > Tomasz Chmielewski <mangoo at wpkg.org> wrote:
> > 
> >> FUJITA Tomonori schrieb:
> >>> On Wed, 09 Jul 2008 08:03:05 +0200
> >>> Tomasz Chmielewski <mangoo at wpkg.org> wrote:
> >>>
> >>>> FUJITA Tomonori schrieb:
> >>>>> On Mon, 30 Jun 2008 10:54:48 +0200
> >>>>> Tomasz Chmielewski <mangoo at wpkg.org> wrote:
> >>>>>
> >>>>>> Tomasz Chmielewski schrieb:
> >>>>>>> ronnie sahlberg schrieb:
> >>>>>>>> Hi Tomasz,
> >>>>>>>>
> >>>>>>>> I could not get that configuration to work.
> >>>>>>>>
> >>>>>>>> Can you please provide more detailed instructions exactly how to set
> >>>>>>>> up hosts A B and C
> >>>>>>>> so I can try to reproduce it.
> >>>>>>>>
> >>>>>>>> Please provide the exact commandline for each and every command I need
> >>>>>>>> to run on the three hosts and Ill try to
> >>>>>>>> reproduce it under gdb.
> >>>>>>> A faulty RAID is just one way to crash tgtd.
> >>>>>>>
> >>>>>>> A simpler one is to just block the traffic between the target and the 
> >>>>>>> initiator - just login to the target, make sure there is some iSCSI 
> >>>>>>> traffic between the target and the initiator, then block incoming iSCSI 
> >>>>>>> traffic on the initiator with:
> >>>>>>>
> >>>>>>> initiator# iptables -I INPUT -s <target IP> -p tcp --sport 3260 -j DROP
> >>>>>>>
> >>>>>>>
> >>>>>>> After a while, you will see that only one tgtd process is running, 
> >>>>>>> whereas the second has crashed.
> >>>>>> Note - the above seems to be valid if:
> >>>>>>
> >>>>>> - there are two initiators connected (from different IPs), perhaps more
> >>>>>> - there is traffic from these two initiators
> >>>>>> - we block traffic on one of these initiators
> >>>>>>
> >>>>>>
> >>>>>> I couldn't reproduce the issue with only one initiator connected.
> >>>>> Can you provide the detailed configuration?
> >>>>>
> >>>>> Do you mean:
> >>>>>
> >>>>> 1. there are three machines, say A, B, and C.
> >>>> yes
> >>>>
> >>>>> 2. you run tgtd on A and setup one target in tgtd.
> >>>> yes
> >>>>
> >>>>> 3. B and C work as an initiator. They connect to A. So the target on A
> >>>>> has two sessions.
> >>>> yes
> >>>>
> >>>>> Then you block the traffic btwwen A and B, then tgtd on A dies?
> >>>>>
> >>>>> Right?
> >>>> Yes, exactly like that.
> >>>> I'm not sure if blocking traffic in both ways is needed, or is it 
> >>>> sufficient/needed to block the traffic from the initiator to the target 
> >>>> (and not from target to the initiator, i.e., -I OUTPUT chain).
> >>> You block the traffic on the initiator and then on the target?
> >> No, only on the initiator.
> >>
> >>
> >>>>> I think that the output of tgtadm will enable us to understand your
> >>>>> configuration easily.
> >>>> What output?
> >>> As I said, the output of tgtadm shows what tgtd has:
> >>>
> >>> Target 1: iqn.2001-04.org.osrg:viola
> >>>     System information:
> >>>         Driver: iscsi
> >>>         State: ready
> >> Aah, this output.
> >>
> >> Nothing special there - two targets configured, each target has one 
> >> initiator coming from a different IP.
> > 
> > Two targets? Hmm, I thought that you have one target machine and
> > configure one target object.
> > 
> > Please tell me about your target objects (configured in tgtd) and
> > physical target machines.
> 
> One target machine with two (or more) targets configured, like below; 
> here is the output - right now, only one initiator is connected; I can 
> reproduce the issue when a second initiator connects, but I can't do it 
> right now.

In your configuration, a second initiator connects to target 2 or
3. Target 1 doesn't have two initiators, right? If so, it's a bit
different from Ronnie's configuration.