Re: generating a TMF
Mike Christie wrote: > Eddy Quicksall wrote: >> Is there a case where the iscsi layer will generate a SCSI TMF? If so, >> what >> are the cases? >> > > Every scsi command has a timer set on it. The value of the timer is > normally 60 seconds. You can see the value for each device here: > /sys/block/sdX/device/timeout > That is RW, so you can echo to it to change the value or you can edit > the udev rule for it (see the README for defaults on that). > > If the command does not complete within the command timeout, the scsi > layer will fire its error handler. The scsi eh will first ask the iscsi > layer if it wants more time. > > In recent kernels (2.6.25 and above or if using the open-iscsi.org > modules with older kernels), the iscsi layer will only ask for more time > if we want to send a nop to check if the target is there and responding > (we will send a nop if we have not got any traffic for > node.conn[0].timeo.noop_out_interval seconds). We do this because the > scsi eh is very slow and has issues, and we only want to run it if we > really have to. > > If it turns out that the connection is good, we let the scsi eh do its > thing. It will first stop all new IO from being sent to the driver. Then > it will try to abort the outstanding tasks by calling the iscsi layer > abort callout which we send a abort task for. If the abort does not > complete within node.session.err_timeo.abort_timeout, we assume the > connection may be bad and just drop the session and try to relogin. If > the abort failed, then we will try a lun reset. If that fails or > timesout (node.session.err_timeo.lu_reset_timeout), we will drop the > session and try to relogin. There are patches floating around to try a > warm target reset after the lun reset, but they had issues with some > targets and is not merged. > Oh yeah, if you run sg_reset -d /dev/sdX you can force the iscsi layer to send a lun reset on /dev/sdX --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: generating a TMF
Eddy Quicksall wrote: > Is there a case where the iscsi layer will generate a SCSI TMF? If so, what > are the cases? > Every scsi command has a timer set on it. The value of the timer is normally 60 seconds. You can see the value for each device here: /sys/block/sdX/device/timeout That is RW, so you can echo to it to change the value or you can edit the udev rule for it (see the README for defaults on that). If the command does not complete within the command timeout, the scsi layer will fire its error handler. The scsi eh will first ask the iscsi layer if it wants more time. In recent kernels (2.6.25 and above or if using the open-iscsi.org modules with older kernels), the iscsi layer will only ask for more time if we want to send a nop to check if the target is there and responding (we will send a nop if we have not got any traffic for node.conn[0].timeo.noop_out_interval seconds). We do this because the scsi eh is very slow and has issues, and we only want to run it if we really have to. If it turns out that the connection is good, we let the scsi eh do its thing. It will first stop all new IO from being sent to the driver. Then it will try to abort the outstanding tasks by calling the iscsi layer abort callout which we send a abort task for. If the abort does not complete within node.session.err_timeo.abort_timeout, we assume the connection may be bad and just drop the session and try to relogin. If the abort failed, then we will try a lun reset. If that fails or timesout (node.session.err_timeo.lu_reset_timeout), we will drop the session and try to relogin. There are patches floating around to try a warm target reset after the lun reset, but they had issues with some targets and is not merged. --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
generating a TMF
Is there a case where the iscsi layer will generate a SCSI TMF? If so, what are the cases? Eddy Will code for food This email and any attached documents may be confidential and property of Wasabi Systems. If you are not the intended recipient, you may not disclose, copy, distribute, or act in reliance on the information in this email. --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
