Changes between Version 6 and Version 7 of DiagnosingSluggishness


Ignore:
Timestamp:
Feb 18, 2008, 6:46:11 PM (10 years ago)
Author:
dkg
Comment:

--

Legend:

Unmodified
Added
Removed
Modified
  • DiagnosingSluggishness

    v6 v7  
    144144}}}
    145145
    146 Note that there are no idle CPU cycles (`id` in the `cpu` section), but a significant amount of cycles in I/O wait (`wa` in `cpu`).  The I/O wait column is new as of Linux kernel 2.6 -- if you're using a 2.4 series kernel, you won't be able to see this.
     146Note that there are no idle CPU cycles (`id` in the `cpu` section), but a significant amount of cycles in I/O wait (`wa` in `cpu`).  The I/O wait column is new as of Linux kernel 2.6 -- if you're using a 2.4 series kernel, you won't be able to see this.  CPU cycles counted in this last column are cycles in which the CPU is idle, but there is an outstanding request to the disks ([https://www.debian-administration.org/users/dkg/weblog/15 or does other I/O count?]).  This indicates that if the I/O had completed, more activity could happen (because the CPU is otherwise idle), so large values in that column are good indicators of a disk throughput problem.
    147147
    148 Note also that `bi` and `bo` are large values (in `io`), though there is no actual swap activity.
    149  
     148Note also that `bi` and `bo` are large values (in `io`), while there is no actual swap activity.  This is helpful to distinguish from an out-of-RAM state.
     149
    150150== Network ==
    151151