I think I might have found a small bug in latest update for SLES12 so this is just a FYI for everyone who made the same mistake I did.
If you use edevices, you know that the FBA driver in linux automagically (like Mark explained it to me few years ago ;) ) creates a device “1” (dasda1 for example) on edevice. You end up with for example dasda + dasda1 and you use dasda1 for OS (including LVM) . No fdisks, no fdasds. I haven’t used edevices in a while so I forgot about that and my recent SLES12 install I did on “dasda” (fba) , instead of “dasda1”. I don’t know how I did that but I did it and SLES install wizard didn’t complain. System installed fine and it is was working ok. pvscan on a build like this returned: Volume Groups with the clustered attribute will be inaccessible. PV /dev/dasda VG root lvm2 [19.53 GiB / 0 free] while in proper installation it looks like this: PV /dev/dasda1 VG lnx15 lvm2 [19.53 GiB / 0 free] Total: 1 [19.53 GiB] / in use: 1 [19.53 GiB] / in no VG: 0 [0 ] Everything was working fine, until I did an update. Something has changed in the way LVM recognizes physical devices and it totally brakes the whole system. It breaks all the parts where LVM is being called which includes the little initrd which is loaded by zipl during the first stage of boot. I did some debugging and I found that with latest update of SLES (I don’t know why because the LVM seems to be in the same version) lvm doesn’t like having metadata on “dasda” (fba) anymore. It likes it only if its on dasda1 When pvscan scans the disk it ends up with: /dev/dasda: Skipping: Partition table signature found so it does not find the label and it fails to bring online the pv and volume group. This edevice, if linked to an original SLES12 or any RHEL is working fine. LVM finds a label on /dev/dasdb (fba) and I can mount it without a problem. I didn’t find anything different in lvm.conf which could cause this. To fix this (well it’s rather a dirty hack), I’ve downloaded a sourcecode of LVM, found the instruction where it exits on message "Skipping: Partition table signature found” , commented out that section, compiled, installed this lvm, rebuilt initrds (both of them) and it worked. I got my system running again. So the lesson is to make sure that SLES is being installed on dasda1 (fba) not dasda (only if you have edevices - with standard ECKDs it’s probably ok to do that) If you already have it on dasda (FBA) - don’t update it without preparations. Perhaps SLES shouldn’t allow to install a system this way at all? Gregory Powiedziuk ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
