The I/O limit feature is available in OpenVZ since kernel 2.6.32-042stab084.3 and vzctl 4.6. This feature allows to limit disk I/O bandwidth available to a container.
Example
root@host# vzctl set 777 --iolimit 3M --save Setting iolimit: 3145728 bytes/sec CT configuration saved to /etc/vz/conf/777.conf
root@host# vzctl enter 777 root@CT:/# cat /dev/urandom | pv -c - >/bigfile3 39.1MB 0:00:10 [ 3MB/s] [ <=> ] ^C
Details
Limit works for reading and writing. There is also a burstable limit which allows 3x normal limit for a very short time.
See also
- vzctl(8), I/O scheduling
- [OpenVZ blog: Yay to I/O limits!
- I/O priorities
- IO accounting