This is a multi-part message in MIME format. --------------000500010209060307080609 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi Ayal, Thanks for that - I was thinking the same after I did some more testing last week - e.g. shared a image file from a different iscsi target and the same iscsi target, the lun on the "same target" changed, the one on the "other target" did again the same - so I figured it had something to do with tgtd. Thanks for below, I was looking into those options to try next week :) ... Thanks Alex On 03/03/2013 06:34 PM, Ayal Baron wrote:
----- Original Message -----
Hi there,
I was doing some testing around ovirt and iscsi and found an issue where as when you use "dd" to create "backing-stores" for iscsi and you point ovirt to it to discover& login, it thinks the LUN ID is the same although the target is different and adds additional paths to the config (automagically?) bringing down the iSCSI storage domain.
There is no question about the behaviour, it's not a bug, that is the way multipathing works (has nothing to do with oVirt). The GUID of a LUN has to be unique. multipathd seeing the same LUN ID across multiple targets assumes that it's the same LUN with multiple paths and that's how you get redundancy and load balancing. Why tgtd doesn't take care of this built in I could never grok, but what you need to do is edit your targets.conf and add the scsi_id and scsi_sn fields.
Example: <target MasterBackup> allow-in-use yes <backing-store /dev/vg0/MasterBackup> lun 1 scsi_id MasterBackup scsi_sn 444444444401 </backing-store> </target>
See attached screenshot of what I got when trying to a "new iscsi san storage domain" to ovirt. The Storage Domain is now down and I cannot get rid of the config (???) how do I force it to logout of the targets ??
Also, anyone know how to deal with the duplicate LUN ID issue ?
Thanks Alex
--
| RHCE | Senior Systems Engineer | www.vcore.co | | www.vsearchcloud.com |
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--------------000500010209060307080609 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 7bit <html> <head> <meta content="text/html; charset=UTF-8" http-equiv="Content-Type"> </head> <body bgcolor="#FFFFFF" text="#000000"> <font size="-1"><font face="Tahoma">Hi Ayal,<br> <br> Thanks for that - I was thinking the same after I did some more testing last week - e.g. shared a image file from a different iscsi target and the same iscsi target, the lun on the "same target" changed, the one on the "other target" did again the same - so I figured it had something to do with tgtd. <br> <br> Thanks for below, I was looking into those options to try next week :) ... <br> <br> Thanks<br> Alex<br> <br> </font></font><br> On 03/03/2013 06:34 PM, Ayal Baron wrote: <blockquote cite="mid:784356398.1626108.1362335643783.JavaMail.root@redhat.com" type="cite"> <pre wrap=""> ----- Original Message ----- </pre> <blockquote type="cite"> <pre wrap=""> Hi there, I was doing some testing around ovirt and iscsi and found an issue where as when you use "dd" to create "backing-stores" for iscsi and you point ovirt to it to discover & login, it thinks the LUN ID is the same although the target is different and adds additional paths to the config (automagically?) bringing down the iSCSI storage domain. </pre> </blockquote> <pre wrap=""> There is no question about the behaviour, it's not a bug, that is the way multipathing works (has nothing to do with oVirt). The GUID of a LUN has to be unique. multipathd seeing the same LUN ID across multiple targets assumes that it's the same LUN with multiple paths and that's how you get redundancy and load balancing. Why tgtd doesn't take care of this built in I could never grok, but what you need to do is edit your targets.conf and add the scsi_id and scsi_sn fields. Example: <target MasterBackup> allow-in-use yes <backing-store /dev/vg0/MasterBackup> lun 1 scsi_id MasterBackup scsi_sn 444444444401 </backing-store> </target> </pre> <blockquote type="cite"> <pre wrap=""> See attached screenshot of what I got when trying to a "new iscsi san storage domain" to ovirt. The Storage Domain is now down and I cannot get rid of the config (???) how do I force it to logout of the targets ?? Also, anyone know how to deal with the duplicate LUN ID issue ? Thanks Alex -- | RHCE | Senior Systems Engineer | <a class="moz-txt-link-abbreviated" href="http://www.vcore.co">www.vcore.co</a> | | <a class="moz-txt-link-abbreviated" href="http://www.vsearchcloud.com">www.vsearchcloud.com</a> | _______________________________________________ Users mailing list <a class="moz-txt-link-abbreviated" href="mailto:Users@ovirt.org">Users@ovirt.org</a> <a class="moz-txt-link-freetext" href="http://lists.ovirt.org/mailman/listinfo/users">http://lists.ovirt.org/mailman/listinfo/users</a> </pre> </blockquote> </blockquote> </body> </html> --------------000500010209060307080609--