Re: Can connection from iscsistart be stopped?
Thanks for the explanation. The rescan seemed to do the trick. I added it to the boot logic, and caught a blade with this error just yesterday. There are 9 LUNs, but when this happens it is always LUN-0 that is missing. A - - - rescan found the missing LUN and created the new device (/dev/sdi). The target is some funky custom box that no one else in the world uses ;) The iscsistart utility returns success, and creates a single session with multiple LUNs. The first one is occasionally missing (say 1 in 25 reboots). I was wondering if our boot script is not waiting long enough between loading the iscsi kernel modules, and running iscsistart. I might play with sleeping for a second between loading the last module, and trying to make the connection. Just in case it is a race condition. Thanks for all the help, Craig On Mar 26, 8:32 am, Mike Christie micha...@cs.wisc.edu wrote: agspoon wrote: Thanks for the tip. Yes, it really is LUN-0 that is missing. All the other LUNs (1-6) do show up in this error condition, and upon reboot they all show up. It is only an occasional boot up where I see LUN-0 missing, and I wanted to avoid a reboot to restore it. I'll give the re-scan trigger a try and see if LUN-0 shows up. What is the magic with the - - - that triggers the scan? A bit of It is : echo BUS_NUMBER TARGET_NUMBER LUN scan - is a wild card. For software iscsi the first two are going to be - or zero (iscsi always just uses 0), and then for LUN can you just use 0 if you are only looking for that one. You can also run iscsiadm iscsiadm -m session -r session_id --rescan or iscsiadm -m session --rescan to scan all sessions. searching shows that many other people know about this, but I've somehow missed it. Is there any documentation that describes this interface (didn't see anything in the kernel docs)? Craig On Mar 25, 7:27 am, Konrad Rzeszutek kon...@virtualiron.com wrote: On Wed, Mar 25, 2009 at 08:26:46AM +0100, Ulrich Windl wrote: On 24 Mar 2009 at 19:47, agspoon wrote: We have an occasional problem where one LUN of a target (LUN-0) does not appear in a connection started by iscsistart. This is in an iscsi- root scenario where iscsistart is called from within the initrd ramdisk image. I don't why this happens, but I can detect when it does. However, I don't know how to stop the connection and try again. If I just re-run iscsistart, it complains that there is already a connection. I tried just pulling out all the iscsi related modules and re-loading them, but they are in use. Hi! I think that's not very iSCSI related, so my guess would be to keep the connection and try a rescan SCSI bus on the SCSI host/connection that you already have. Also, do you really need LUN 0? Disks are usually assigned to a LUN != 0. They are with some iSCSI targets (MD3000i, DS3300, AX150, CX300, Compelant, DataCore, and some other ones). Do you have any other LUNs on the target except LUN-0? Do they show up? If not, you can do 'echo - - - /sys/class/scsi_host/hostX/scan to retrigger the scan. That should make the LUN-0 and others show up. You will have to figure out the hostX relation to /sys/class/iscsi_session/sessionY yourself. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups open-iscsi group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to open-iscsi+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: Can connection from iscsistart be stopped?
agspoon wrote: We have an occasional problem where one LUN of a target (LUN-0) does not appear in a connection started by iscsistart. This is in an iscsi- root scenario where iscsistart is called from within the initrd ramdisk image. I don't why this happens, but I can detect when it does. However, I don't know how to stop the connection and try again. If I just re-run iscsistart, it complains that there is already a connection. I tried just pulling out all the iscsi related modules and re-loading them, but they are in use. Does iscsistart return success for the login or does that return a error? How many luns are exposed on this target/session? If there are multiple luns do some show up and others do not? What target are you using? Does it do a session per lun? Some targets like Equalogic will create a target per lun so we end up with a session per lun. Is there some way to stop the connection so that I can reinvoke iscsistart and see all of my LUNs? Some trick with /proc or /sys? I don't have much to work with in this early user space environment, and I don't want it to grow too big. Any thoughts? Thanks, Craig --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups open-iscsi group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to open-iscsi+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: Can connection from iscsistart be stopped?
agspoon wrote: Thanks for the tip. Yes, it really is LUN-0 that is missing. All the other LUNs (1-6) do show up in this error condition, and upon reboot they all show up. It is only an occasional boot up where I see LUN-0 missing, and I wanted to avoid a reboot to restore it. I'll give the re-scan trigger a try and see if LUN-0 shows up. What is the magic with the - - - that triggers the scan? A bit of It is : echo BUS_NUMBER TARGET_NUMBER LUN scan - is a wild card. For software iscsi the first two are going to be - or zero (iscsi always just uses 0), and then for LUN can you just use 0 if you are only looking for that one. You can also run iscsiadm iscsiadm -m session -r session_id --rescan or iscsiadm -m session --rescan to scan all sessions. searching shows that many other people know about this, but I've somehow missed it. Is there any documentation that describes this interface (didn't see anything in the kernel docs)? Craig On Mar 25, 7:27 am, Konrad Rzeszutek kon...@virtualiron.com wrote: On Wed, Mar 25, 2009 at 08:26:46AM +0100, Ulrich Windl wrote: On 24 Mar 2009 at 19:47, agspoon wrote: We have an occasional problem where one LUN of a target (LUN-0) does not appear in a connection started by iscsistart. This is in an iscsi- root scenario where iscsistart is called from within the initrd ramdisk image. I don't why this happens, but I can detect when it does. However, I don't know how to stop the connection and try again. If I just re-run iscsistart, it complains that there is already a connection. I tried just pulling out all the iscsi related modules and re-loading them, but they are in use. Hi! I think that's not very iSCSI related, so my guess would be to keep the connection and try a rescan SCSI bus on the SCSI host/connection that you already have. Also, do you really need LUN 0? Disks are usually assigned to a LUN != 0. They are with some iSCSI targets (MD3000i, DS3300, AX150, CX300, Compelant, DataCore, and some other ones). Do you have any other LUNs on the target except LUN-0? Do they show up? If not, you can do 'echo - - - /sys/class/scsi_host/hostX/scan to retrigger the scan. That should make the LUN-0 and others show up. You will have to figure out the hostX relation to /sys/class/iscsi_session/sessionY yourself. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups open-iscsi group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to open-iscsi+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: Can connection from iscsistart be stopped?
On 24 Mar 2009 at 19:47, agspoon wrote: We have an occasional problem where one LUN of a target (LUN-0) does not appear in a connection started by iscsistart. This is in an iscsi- root scenario where iscsistart is called from within the initrd ramdisk image. I don't why this happens, but I can detect when it does. However, I don't know how to stop the connection and try again. If I just re-run iscsistart, it complains that there is already a connection. I tried just pulling out all the iscsi related modules and re-loading them, but they are in use. Hi! I think that's not very iSCSI related, so my guess would be to keep the connection and try a rescan SCSI bus on the SCSI host/connection that you already have. Also, do you really need LUN 0? Disks are usually assigned to a LUN != 0. Is there some way to stop the connection so that I can reinvoke iscsistart and see all of my LUNs? Some trick with /proc or /sys? I don't have much to work with in this early user space environment, and I don't want it to grow too big. Any thoughts? Novell/SUSE has a script to rescan the busses. If needed, I could send it to you. Regards, Ulrich --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups open-iscsi group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to open-iscsi+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: Can connection from iscsistart be stopped?
On Wed, Mar 25, 2009 at 08:26:46AM +0100, Ulrich Windl wrote: On 24 Mar 2009 at 19:47, agspoon wrote: We have an occasional problem where one LUN of a target (LUN-0) does not appear in a connection started by iscsistart. This is in an iscsi- root scenario where iscsistart is called from within the initrd ramdisk image. I don't why this happens, but I can detect when it does. However, I don't know how to stop the connection and try again. If I just re-run iscsistart, it complains that there is already a connection. I tried just pulling out all the iscsi related modules and re-loading them, but they are in use. Hi! I think that's not very iSCSI related, so my guess would be to keep the connection and try a rescan SCSI bus on the SCSI host/connection that you already have. Also, do you really need LUN 0? Disks are usually assigned to a LUN != 0. They are with some iSCSI targets (MD3000i, DS3300, AX150, CX300, Compelant, DataCore, and some other ones). Do you have any other LUNs on the target except LUN-0? Do they show up? If not, you can do 'echo - - - /sys/class/scsi_host/hostX/scan to retrigger the scan. That should make the LUN-0 and others show up. You will have to figure out the hostX relation to /sys/class/iscsi_session/sessionY yourself. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups open-iscsi group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to open-iscsi+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Can connection from iscsistart be stopped?
We have an occasional problem where one LUN of a target (LUN-0) does not appear in a connection started by iscsistart. This is in an iscsi- root scenario where iscsistart is called from within the initrd ramdisk image. I don't why this happens, but I can detect when it does. However, I don't know how to stop the connection and try again. If I just re-run iscsistart, it complains that there is already a connection. I tried just pulling out all the iscsi related modules and re-loading them, but they are in use. Is there some way to stop the connection so that I can reinvoke iscsistart and see all of my LUNs? Some trick with /proc or /sys? I don't have much to work with in this early user space environment, and I don't want it to grow too big. Any thoughts? Thanks, Craig --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups open-iscsi group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to open-iscsi+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
