IO limits are not working on XFS filesystem.

Issue

LVE limits, including IO limit, are set but dd test shows higher performance:

      ID   SPEED    PMEM    VMEM      EP   NPROC      IO    IOPS
 migrate     100   2048M      0K      20     100   15360    1024

[root@da75venom ~]# su - migrate
[migrate@da75venom ~]$ dd if=/dev/zero of=test.block bs=1M count=1024 conv=fdatasync
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 6.06703 s, 177 MB/s

Environment

• CloudLinux OS 6/7

Solution

The bug KMODLVE-485 has been fixed and the kernel released to the production. Please perform an update using this link.

Cause

XFS specification.