Hi Eric, On Fri, 2014-06-13 at 21:59 +0000, Eric Murphy wrote: > I know this is probably not the best place to ask, but I can't find > any information anywhere. I've got a server with 4x1 Gb links, each > with their own IP, being access by some VMWare hosts. > Every so often - about every 30-60 minutes - journalctl will fill up > with the following error: > > kernel: TARGET_CORE[iSCSI]: Detected NON_EXISTENT_LUN Access for > 0x00000001 > > It then repeat this, incrementing by one until it hits 0x000000ff and > then it stops, which takes 1 or 2 seconds. > There is nothing in the log before or after these - sometimes this > happens 10 or more minutes after the last entry in journalctl, and it > can be a considerable amount of time afterwards before something else > is logged as well. > > None of the VM's or hosts accessing the iSCSI target report anything > at all, and they seem to run just fine, no odd slowness or > anything . > > I started with all of the luns on a single target, counting from 0 to > 5, and then tried putting each lun on its own iqn, so I wound up with > 6 iqn's with a single lun zero, in both setups the same thing > happened. > > So my question is - do I need to worry about this, or is it something > I can ignore? Also if I can ignore it, is there some way to mask it > so it doesn't show up in journalctl? > > The operating system is RedHat 7.0 Release (Maipo) with kernel > 3.10.0-123.1.2.el7.x86_64 > > This is simply ESX re-scanning the target side LUN layout on an individual iSCSI target instance, and aside from the extra warnings you've noticed above there is nothing to be concerned about on the target side. It is kind of unusual that ESX is (automatically) doing this every 30-60 minutes, as it's usually manually initiated by admin with vicfg-rescan. Looking around a bit more, there is a kb entry for explicitly disabling the automatic rescanning logic in vCenter: http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1016873 Apparently the 'rescan storms' do cause problems on some targets, but we've not had any issues thus far reported related to the automatic rescanning. That said, disabling it and using vicfg-rescan manually when the LUN layout changes what can be done to avoid the extra noise. --nab -- To unsubscribe from this list: send the line "unsubscribe target-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
