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Date:      Fri, 23 Jun 2006 19:12:54 -0300 (ADT)
From:      "Marc G. Fournier" <scrappy@hub.org>
To:        Charles Swiger <cswiger@mac.com>
Cc:        freebsd-stable@freebsd.org
Subject:   Re: vmstat 'b' (disk busy?) field keeps climbing ...
Message-ID:  <20060623191131.C1114@ganymede.hub.org>
In-Reply-To: <261AD16B-C3FE-4671-996E-563053508CE8@mac.com>
References:  <20060623172557.H1114@ganymede.hub.org> <261AD16B-C3FE-4671-996E-563053508CE8@mac.com>

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On Fri, 23 Jun 2006, Charles Swiger wrote:

> On Jun 23, 2006, at 4:44 PM, Marc G. Fournier wrote:
>> procs      memory      page                    disks     faults      cpu
>> r b w     avm    fre  flt  re  pi  po  fr  sr da0 pa0   in   sy  cs us sy 
>> id
>> 1 42 1 10249060 161668 1290  54  12   3 1409 2202 102   0  751 6416 3350 24 
>> 15 61
>> 0 39 0 10148976 148104  654  10   5   2 660   0  49   0  615 4440 2584 18 
>> 9 73
>> 
>> the last time it hung, it hit about 45 ... about 6 hours ago, it was at 
>> ~5-10 ... anything I should look at to figure out where those 39+ are 
>> 'busy'?
>
> 'b' stands for "blocked", not "busy".  Judging by your page fault rate and 
> the high number of frees and pages being scanned, you're probably swapping 
> tasks in and out and are waiting on disk.  Take a look at "vmstat -s", and 
> consider adding more RAM if this is correct...

'k, I will keep an eye on things and check vmstat -s as those numbers grow 
higher ... thanks for hte clarification on 'blocked' vs 'busy' :(

What specifically should I be looking at in vmstat -s?  note that the 
server just rebooted, 0 swap is used:

# pstat -s
Device          1K-blocks     Used    Avail Capacity
/dev/da0s1b       8388608        0  8388608     0%

and vmstat -s is showing:

# vmstat -s
   8434656 cpu context switches
   2554513 device interrupts
    430486 software interrupts
   4353484 traps
  21299255 system calls
        36 kernel threads created
     28399  fork() calls
      1708 vfork() calls
         0 rfork() calls
         0 swap pager pageins
         0 swap pager pages paged in
         0 swap pager pageouts
         0 swap pager pages paged out
     31750 vnode pager pageins
    209538 vnode pager pages paged in
     15954 vnode pager pageouts
    219494 vnode pager pages paged out
        20 page daemon wakeups
    648514 pages examined by the page daemon
     16508 pages reactivated
   1014412 copy-on-write faults
      5389 copy-on-write optimized faults
   1982109 zero fill pages zeroed
   1070481 zero fill pages prezeroed
      1626 intransit blocking page faults
   3786729 total VM faults taken
         0 pages affected by kernel thread creation
   2344822 pages affected by  fork()
    299231 pages affected by vfork()
         0 pages affected by rfork()
   3360377 pages freed
         0 pages freed by daemon
   1672560 pages freed by exiting processes
    618892 pages active
    275063 pages inactive
     42967 pages in VM cache
     66898 pages wired down
      6398 pages free
      4096 bytes per page
  36972009 total name lookups
           cache hits (97% pos + 0% neg) system 0% per-directory
           deletions 0%, falsehits 0%, toolong 0%

thx ...

----
Marc G. Fournier           Hub.Org Networking Services (http://www.hub.org)
Email . scrappy@hub.org                              MSN . scrappy@hub.org
Yahoo . yscrappy               Skype: hub.org        ICQ . 7615664



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