SWAP usage 100%

[mojsiuk]

We have the same situation after upgrade 3 nodes cluster to 7.4 from 6.4 and increasing ram on node 1 with additional 128GB. Is there any solution? We change parameters in systemct to vm.swappiness=10.

 

[LnxBil]

Is there any solution?

Depends on the cause. There is enough information in this thread to analyze the problem further, yet no one provided the necessary information.

 

[r2d23k]

Hi,

Anybody know how to troubleshoot this?

 

[nicoska]

Hi all,

also I keep seeing SWAP full. Really strange:

 

[Kingneutron]

It seems to me like there is an excessive amount of swap configured. Anything above ~16GB of RAM on the host level, you don't want your server to swap much at all.


In my /etc/rc.local with zram enabled + 2GB of LVM swap (16GB host RAM):

echo 1 > /proc/sys/vm/swappiness


# Try to keep at least 100MB of free RAM at all times
echo 100000 > /proc/sys/vm/min_free_kbytes


# Default 100 - try more aggressively to reclaim inodes, etc from cache
echo 160 > /proc/sys/vm/vfs_cache_pressure

I'm also limiting ZFS ARC usage to 1573741824 bytes (~1.5GB), and have LVM + ext4 root.


Right now I have (5) VMs running and 2 containers, and (54MB) of 4GB swap usage:

swapon -s;free -h


Filename                                Type            Size            Used            Priority
/dev/dm-0                               partition       2097148         0               -2
/dev/zram0                              partition       2097148         55296           10

               total        used        free      shared  buff/cache   available
Mem:            15Gi        11Gi       2.4Gi        48Mi       1.7Gi       3.7Gi
Swap:          4.0Gi        54Mi       3.9Gi