Hi, I found yesterday a problem which could result in a server failing to boot once it is upgraded from SLES 12 to 15 and then to recently released SP3. I thought I should warn those here just in case.
My environment is running under z/VM, the servers use defined minidisks for /, /usr and /var and two swap partitions defined as vdisks and formatted using swapgen prior to boot. What I found is that if you have a server that is SLES 12, then upgraded to SLES 15 GA or SP1 or SP2, all works fine. However, if you then upgrade the same server to SP3 OR if you simply upgrade directly from SLES12SP5 to SLES15SP3, then you will encounter this problem. You will not see this problem if this was a fresh install of SLES 15 and upgrading to SP3. The problem only surfaces when you go to SP3. The upgrade to SP3 appears to cause a change in the udev definitions for the DASD defined on the server (in /etc/udev/rules.d) . For SLES 12 systems, these rules are 51-dasd-0.0.0xxx.rules files but it seems that for SLES15, they change format and number to 41-dasd-eckd-0.0.0xxx.rules. However, this change does not happen for an upgraded SLES12 system to SLES15 until you upgrade to SLES15SP3. Once you upgrade to SP3, then the old 51-dasd rules are renamed with the '.legacy' extensions, new 41- rules are created. The rules for the vdisk for swap are left alone and thus after the upgrade, the swap partitions are no longer activated. There is more to this but I will not go into detail. However, that's not the problem. At this point, if you attempt to do any change to the bootloader or run mkinitrd, for instance if you use Yast to update DASD and 'Activate' the swap disks or any disk for that matter, causing mkinitrd to run as well as grub2-intall, this will write a faulty boot loader and the system will no longer boot if it were to be rebooted. You can use a rescue system to fix the broken boot but if you were to run the above process again, the same will happen. This is risky because you may not reboot for 6 months and then you find out this is the case. I have reported to SUSE but no response as of now. Thanks, Aria ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www2.marist.edu/htbin/wlvindex?LINUX-390
