iostat reports zero throughput with Smart Array Controllers (cciss)

  • 3948059
  • 05-Feb-2008
  • 30-Apr-2012


Novell SUSE Linux Enterprise Server 9 (SLES9)
Novell Open Enterprise Server (Linux based)
Novell Linux Desktop 9 (NLD9)

Compaq/HP Smart Array Controller (cciss driver)


The throughput data for the disks on the Smart Array Controller reported by iostat ("Blk_read/s", "Blk_wrtn/s", "Blk_read", "Blk_wrtn") and iostat -x ("rsec/s", "wsec/s", "rkB/s", "wkB/s" and "avgrq-sz") are all reported as 0 (zero).


Update the kernel.

This issue is fixed as of kernel 2.6.5-7.286 and a fixed kernel isincluded in SLES9 Service Pack 4 and NLD9 Service Pack 4.

The cciss driver in kernels prior to 2.6.5-7.286 did not contain the cciss-cpq-disk-stats patch which makes the driver update the disk statistics kept by the kernel. iostat relies on these statistics for throughput information.