View Issue Details
ID | Project | Category | View Status | Date Submitted | Last Update |
---|---|---|---|---|---|
0012082 | CentOS-7 | kernel | public | 2016-10-17 07:44 | 2016-10-20 16:18 |
Reporter | oomalley | Assigned To | |||
Priority | normal | Severity | minor | Reproducibility | always |
Status | resolved | Resolution | no change required | ||
OS | CentOS | OS Version | 7 | ||
Product Version | 7.2.1511 | ||||
Summary | 0012082: Disabling KSM Merging Memory Across NUMA Nodes Failes with "write error: Device or resource busy". | ||||
Description | Unable to disable KSM merging memory across NUMA nodes. I can read /sys/kernel/mm/ksm/merge_across_nodes but not write to it. For instance; Reading Works; cat /sys/kernel/mm/ksm/merge_across_nodes 1 Writing fails; echo 0 > /sys/kernel/mm/ksm/merge_across_nodes -bash: echo: write error: Device or resource busy Similarly, attempting same change with virsh; virsh node-memory-tune --shm-merge-across-nodes 0 error: Unable to change memory parameters error: failed to set shm_merge_across_nodes: Operation not permitted | ||||
Steps To Reproduce | echo 0 > /sys/kernel/mm/ksm/merge_across_nodes -bash: echo: write error: Device or resource busy | ||||
Additional Information | uname -a Linux XXXXXXXXXXXXXXX 3.10.0-327.28.2.el7.x86_64 #1 SMP Wed Aug 3 11:11:39 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux virsh --version 1.2.17 | ||||
Tags | kvm | ||||
abrt_hash | |||||
URL | |||||
Also note, we have multiple KVM hosts configured pretty much identically, but this issue only affects a subset of them. All servers run the same package version sourced from an internal repo. Rebooting does not resolve. Neither does stopping guest VMs and/or ksm and ksmtuned daemons. |
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Qemu-KVM version 1.5.3 installed. | |
Resolved, not a Bug. /sys/kernel/mm/ksm/pages_shared must be 0 and theretofore first be unmerge with; echo 2 > /sys/kernel/mm/ksm/run See further discussion here; https://www.centos.org/forums/viewtopic.php?f=47&t=59749 |
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Date Modified | Username | Field | Change |
---|---|---|---|
2016-10-17 07:44 | oomalley | New Issue | |
2016-10-17 07:44 | oomalley | Tag Attached: kvm | |
2016-10-17 07:46 | oomalley | Tag Attached: ke | |
2016-10-17 07:46 | oomalley | Tag Detached: ke | |
2016-10-17 07:55 | oomalley | Note Added: 0027725 | |
2016-10-17 07:58 | oomalley | Note Added: 0027726 | |
2016-10-20 01:38 | oomalley | Note Added: 0027756 | |
2016-10-20 16:18 | toracat | Status | new => resolved |
2016-10-20 16:18 | toracat | Resolution | open => no change required |