[CentOS-virt] Problems with scsi-target-utils when hosted on dom0 centos 7 xen box

Tue Apr 12 16:43:04 UTC 2016

By natively, I take it using
kernel /vmlinuz (vs kernel /xen)

Not yet, but working on setting up such an environment.

(At this time, I was using virt-install to reproduce the problem, and 
the original server we are testing on did not support kvm but the 2nd 
server does).

On 2016-04-12 03:26 AM, George Dunlap wrote:
> On Mon, Apr 11, 2016 at 9:14 PM, Nathan Coulson <nathan at bravenet.com> wrote:
>> Hello
>>
>> We were attempting to use scsi-target-utils, hosted on a xen dom0 vm using
>> localhost, and running into some problems.  I was not able to reproduce this
>> on a centos 7.2 server using the default kernel.
> Have you tried booting the Virt SIG kernel natively and seeing if you
> can reproduce the problem at all?
>
> Thanks,
>   -George
>
>>
>> (From dmesg)
>> Apr  4 11:18:42 funk kernel: [  596.511204]  connection2:0: detected conn
>> error (1022)
>> Apr  4 11:18:42 funk kernel: connection2:0: ping timeout of 5 secs expired,
>> recv timeout 5, last rx 4295253788, last ping 4295258790, now 4295263808
>> Apr  4 11:18:42 funk kernel: connection2:0: detected conn error (1022)
>> Apr  4 11:18:42 funk iscsid: Kernel reported iSCSI connection 2:0 error
>> (1022 - Invalid or unknown error code) state (3)
>> Apr  4 11:18:44 funk iscsid: connection2:0 is operational after recovery (1
>> attempts)
>>
>> Repeated a few times, until eventually
>>
>>
>> Apr  4 11:19:44 funk kernel: Result: hostbyte=DID_TRANSPORT_DISRUPTED
>> driverbyte=DRIVER_OK
>> Apr  4 11:19:44 funk kernel: sd 7:0:0:1: [sdd] CDB:
>> Apr  4 11:19:44 funk kernel: Write(10): 2a 00 01 df c7 e8 00 00 18 00
>> Apr  4 11:19:44 funk kernel: blk_update_request: I/O error, dev sdd, sector
>> 31442920
>> Apr  4 11:19:44 funk kernel: [  658.127596] sd 7:0:0:1: [sdd]
>> Apr  4 11:19:44 funk kernel: [  658.127688] Result:
>> hostbyte=DID_TRANSPORT_DISRUPTED driverbyte=DRIVER_OK
>> Apr  4 11:19:44 funk kernel: [  658.127761] sd 7:0:0:1: [sdd] CDB:
>> Apr  4 11:19:44 funk kernel: [  658.127826] Write(10): 2a 00 01 df c7 e8 00
>> 00 18 00
>> Apr  4 11:19:44 funk kernel: [  658.127927] blk_update_request: I/O error,
>> dev sdd, sector 31442920
>> Apr  4 11:19:44 funk kernel: [  658.128040] sd 7:0:0:1: [sdd]
>> Apr  4 11:19:44 funk kernel: sd 7:0:0:1: [sdd]
>> Apr  4 11:19:44 funk kernel: [  658.128105] Result:
>> hostbyte=DID_TRANSPORT_DISRUPTED driverbyte=DRIVER_OK
>> Apr  4 11:19:44 funk kernel: [  658.128177] sd 7:0:0:1: [sdd] CDB:
>> Apr  4 11:19:44 funk kernel: [  658.128241] Write(10): 2a 00 00 00 08 00 00
>> 00 18 00
>> Apr  4 11:19:44 funk kernel: [  658.128339] blk_update_request: I/O error,
>> dev sdd, sector 2048
>> Apr  4 11:19:44 funk kernel: Result: hostbyte=DID_TRANSPORT_DISRUPTED
>> driverbyte=DRIVER_OK
>> Apr  4 11:19:44 funk kernel: sd 7:0:0:1: [sdd] CDB:
>> Apr  4 11:19:44 funk kernel: Write(10): 2a 00 00 00 08 00 00 00 18 00
>> Apr  4 11:19:44 funk kernel: blk_update_request: I/O error, dev sdd, sector
>> 2048
>>
>>
>> (Test Setup)
>> scsi-target-utils installed via yum, default config
>> /etc/tgt/conf.d/xenguests.conf
>> <target iqn.2016-02.com.bravenet:test>
>>      backing-store //mnt/vmdisk/test # vm image
>> </target>
>>
>> systemctl tgtd restart
>>
>> iscsiadm -m discovery -t sendtargets -p localhost
>>
>> iscsiadm -m node -T iqn.2016-02.com.bravenet:test -l
>>
>>
>> add it to lvm (pvcreate, vgcreate), let's call it /dev/vmdisk.vg/test.lv
>>
>> and then use libvirt to attempt to install an os on /dev/vmdisk.vg/test.lv
>> (using anaconda)
>>
>>
>>
>>
>> Around the time it tries to create the disk label, is when the conn errors
>> start, until eventually it gives up trying to create the disk label.
>>
>>
>>
>> We tested a similar setup on a centos 7.2 host we use kvm based
>> virtualmachine hosting on (default 3.10 kernel), and it worked fine.  It may
>> be similar to what was reported on
>> https://bugzilla.redhat.com/show_bug.cgi?id=1245990, but I never saw a
>> resolution on what they discovered (other then a reference to comment18
>> which does not appear to exist).
>>
>> Testing over the network appears to also work as well (where another machine
>> connects to scsi-target-utils on the funk server above.
>>
>>
>>
>>
>>
>> Longterm Purpose of the above setup, was to get direct access to a
>> filesystem image hosted on a gluster setup, using bs-type glfs on
>> scsi-target-utils.
>>
>> --
>> Nathan Coulson
>> www.bravenet.com
>> nathan at bravenet.com
>> _______________________________________________
>> CentOS-virt mailing list
>> CentOS-virt at centos.org
>> https://lists.centos.org/mailman/listinfo/centos-virt
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-- 
Nathan Coulson
System Administrator for Bravenet
www.bravenet.com
nathan at bravenet.com