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Description of problem: Starting with RHEL 7.2 standby memory on z/VM is automatically onlined whereas it should stay offline until it is manually onlined later on when needed. I've tracked this down to systemd BZ 1105020 that added udev rule to auto online newly added memory. This works on some architectures but causes this regression on z/VM where the hotplug memory is always present but only onlined when needed. Relevant commit https://github.com/lnykryn/systemd-rhel/commit/57adc4317ee2553d2d3ac84ef9625ed9c1cf5700 Version-Release number of selected component (if applicable): systemd-219-19.el7_2.12.s390x How reproducible: always Steps to Reproduce: 1. create z/VM with standby memory USER XXXXX YYYYY 1G 2G GC COMMAND DEFINE STORAGE 1G STANDBY 1G COMMAND SET RUN ON 2. boot Actual results: [root@ibm-z-03 ~]# lsmem -a Address Range Size (MB) State Removable Device =============================================================================== 0x0000000000000000-0x000000000fffffff 256 online no 0-127 0x0000000010000000-0x000000001fffffff 256 online yes 128-255 0x0000000020000000-0x000000002fffffff 256 online yes 256-383 0x0000000030000000-0x000000003fffffff 256 online no 384-511 0x0000000040000000-0x000000004fffffff 256 online no 512-639 0x0000000050000000-0x000000005fffffff 256 online no 640-767 0x0000000060000000-0x000000006fffffff 256 online no 768-895 0x0000000070000000-0x000000007fffffff 256 online no 896-1023 Expected results: [root@ibm-z-03 ~]# lsmem -a Address Range Size (MB) State Removable Device =============================================================================== 0x0000000000000000-0x000000000fffffff 256 online no 0-127 0x0000000010000000-0x000000001fffffff 256 online yes 128-255 0x0000000020000000-0x000000002fffffff 256 online yes 256-383 0x0000000030000000-0x000000003fffffff 256 online no 384-511 0x0000000040000000-0x000000004fffffff 256 offline - 512-639 0x0000000050000000-0x000000005fffffff 256 offline - 640-767 0x0000000060000000-0x000000006fffffff 256 offline - 768-895 0x0000000070000000-0x000000007fffffff 256 offline - 896-1023 Additional info:
I guess we could make this udev rule conditional and skip it on z/VM systems. Can you please provide output of systemd-detect-virt from this machine?
sure [root@ibm-z-03 ~]# systemd-detect-virt zvm
I modified udev rule as follows, SUBSYSTEM=="memory", ACTION=="add", PROGRAM="/usr/bin/systemd-detect-virt", RESULT!="zvm", ATTR{state}=="offline", ATTR{state}="online" This rule was confirmed to work as expected by Milos.
Michal, turns out this is not only z/VM problem as IBM reports. This is what we were told "Rereading the Bugzilla, I found that the problem description seems to be limited to z/VM environment. Actually the problem occurs even in native LPAR." I've asked for systemd-virt-detect output to see if we can simply tweak the rule to this additional platform. Milos
fix merged to upstream staging branch -> https://github.com/lnykryn/systemd-rhel/commit/ad9ec899fe24c4b74841a30f9233cee3bd7a3287 https://github.com/lnykryn/systemd-rhel/commit/195083a33b4204d513787e7f4b6c63f19a0fe1c7 -> post
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHBA-2016-2216.html