This sounds very familiar...
https://bugzilla.redhat.com/show_bug.cgi?id=1250060
and they rolled it back in
https://bugzilla.redhat.com/show_bug.cgi?id=1779609
because upstream didn't accept their patch.
We had to "fix" our memory monitoring twice because of this.
It's important to *not* calculate buffer/cache memory towards memory usage,
because the kernel can reclaim this memory whenever there is a need.
________________________________
From: li jerry <div...@hotmail.com>
Sent: 15 July 2020 08:27
To: users@cloudstack.apache.org <users@cloudstack.apache.org>
Subject: KVM host AvailableMemory data is incorrect
Hello everyone
We use HCI to run CloudStack (KVM+CEPH). After running for a period of
time, cloudstack reports that HOST has no available memory. But ZABBIX
monitoring shows that HOST still has a lot of available memory. By observing
/proc/meminfo on KVM HOST, it is found that most of the memory is occupied by
Buffers.
Further analysis of the source code of cloudstack-agent shows that the
algorithm for cloudstack-agent to obtain AvailableMemory on the host is:
Cached +MemFree -reservedMemory +overCommitMemory
It does not calculate the memory occupied by Buffers.
Excuse me, can I mark the memory occupied by Buffers as AvailableMemory?
If not, what is the reason?
Thank you!
- Jerry
