The kernel tunable fs.aio-max-nr specifies the maximum number of events
specified on the io_setup() call for all currently active aio contexts.
On large systems this causes issues with the io_setup() call failing
with EAGAIN. Libvirt already increases this setting to 1048576:
96e99e4948/src/remote/libvirtd.sysctl
The only potential drawback of a larger limit is that a malicious users
could issue parallel io_setup() requests to cause the kernel to set
aside memory.
Signed-off-by: Jiri Mencak <jmencak@users.noreply.github.com>
AWS Nitro instances need special tuning for NVMe devices:
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/nvme-ebs-volumes.html#timeout-nvme-ebs-volumes
[sysfs]
/sys/module/nvme_core/parameters/io_timeout=4294967295
/sys/module/nvme_core/parameters/max_retries=10
This tuning should probably be moved to Cloud Provider-specific profiles
once the functionality is implemented.
Signed-off-by: Jiri Mencak <jmencak@users.noreply.github.com>
The [scheduler] plug-in can be very CPU intensive, especially on the
OpenShift platform. The bug for this issue is tracked by rhbz#1921738.
Until this is fixed, work around this problem in the openshift
parent profile by adding "runtime=0" [scheduler] plug-in option.
Signed-off-by: Jiri Mencak <jmencak@users.noreply.github.com>
