1 LXC Makes Server Load 400!

[kotakomputer]

I really don't understand how LXC works. I have only 10 LXC, CPU usage 20%, but 1 of my LXC has cpu usage 100% and caused Server Load 400!

How to prevent this one LXC overloaded whole server?
This overloaded LXC has Cores = 1, CPU Limit = 0, CPU Units = 1000

 

[janos]

Hi,

When process in LXC container reach the CPU limit (in tihs case using 100% CPU), it start waiting for CPU time, what cause the high load number. Basically this is normal.

 

[kotakomputer]

How to prevent this LXC eat all server resources? Since Server Load 400 all others LXC freeze. Basically this is not VPS used for

 

[janos]

Hi,

High load itself not mean the system need to be slow or unresponsible. You not wrote this information earlier.

 

[mailinglists]

Try to limit disks trhoughput and IOPS for that problematic VPS.

 

[kotakomputer]

Try to limit disks trhoughput and IOPS for that problematic VPS.

But LXC has no feature to limit disk Throughput and IOPS, right?

 

[janos]

But LXC has no feature to limit disk Throughput and IOPS, right?

right.

 

[mailinglists]

Sorry, my bad.
I use KVM for shared servers, where this is an option.
I use LXC only where I have my own instances or where all instances belong to the same user.

When load goes up, do check which resources are lacking. You can check top for waiting percentage - wa (to see if they are waiting for disks) or CPU load.
If you have them waiting for disks, either increase speed of your disks (different setup or hardware) or switch over to KVM and limit IOPS and throughput. What does pveperf say when host is not under load?