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

[FUJITA Tomonori]

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?


> > 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
    I_T nexus information:
        I_T nexus: 1
            Initiator: iqn.2005-03.org.open-iscsi:773eff7d5a
            Connection: 0
                IP Address: 10.76.0.28
    LUN information:
        LUN: 0
            Type: controller
            SCSI ID: deadbeaf1:0
            SCSI SN: beaf10
            Size: 0 MB
            Online: Yes
            Removable media: No
            Backing store: No backing store
        LUN: 1
            Type: disk
            SCSI ID: deadbeaf1:1
            SCSI SN: beaf11
            Size: 2147 MB
            Online: Yes
            Removable media: No
            Backing store: /var/tmp/image0
    Account information:
    ACL information:
        ALL


> It doesn't happen if tgtd is started in the foreground.

Hmm, strange. Anyway, I will try to reproduce this tomorrow.