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From:Dan Nelson Date:May 8 2005 1:42am
Subject:Re: MySQL not using optimum disk throughput.
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In the last episode (May 07), Atle Veka said:
> On Fri, 6 May 2005, Kevin Burton wrote:
> > For the record... no a loaded system what type of IO do you guys
> > see? Anywhere near full disk capacity?  I'm curious to see what
> > type of IO people are seeing on a production/loaded mysql box.
> 
> Mostly Linux in this thread so far, so I figured I'd throw some
> FreeBSD in the mix. Our latest build which so far has worked out
> great, is MySQL 4.0.24 with linuxthreads on FreeBSD 4.10-R.
> 
> 1) 15k RPM SCSI in RAID-10 configuration:
> Threads: 61  Questions: 192440153  Slow queries: 1600  Opens: 361204
> Flush tables: 1  Open tables: 128  Queries per second avg: 199.496
> 
>       tty             da0              fd0            pass0             cpu
>  tin tout  KB/t tps  MB/s   KB/t tps  MB/s   KB/t tps  MB/s  us ni sy in id
>    0   19 16.00   3  0.05   0.00   0  0.00   0.00   0  0.00   0  1  3  1 95
>    0   19 16.00   7  0.11   0.00   0  0.00   0.00   0  0.00   0  0  3  0 97
>    0   19 16.00   5  0.08   0.00   0  0.00   0.00   0  0.00   0  1  4  0 95
>    0   19 16.00   1  0.02   0.00   0  0.00   0.00   0  0.00   0  1  3  0 96
>    0   19 16.00   7  0.11   0.00   0  0.00   0.00   0  0.00   0  1  1  0 98
> 
> 2) 15k RPM SCSI (single disk, no raid)
> Threads: 427  Questions: 929834784  Slow queries: 99  Opens: 421800  Flush
> tables: 2  Open tables: 128  Queries per second avg: 467.845
> 
>       tty             da0              fd0            pass0             cpu
>  tin tout  KB/t tps  MB/s   KB/t tps  MB/s   KB/t tps  MB/s  us ni sy in id
>    0   38 64.00   1  0.06   0.00   0  0.00   0.00   0  0.00   3  3 16  1 76
>    0   38 64.00   1  0.06   0.00   0  0.00   0.00   0  0.00   4  2 18  1 75
>    0   38 64.00   1  0.06   0.00   0  0.00   0.00   0  0.00   1  2 13  4 80
>    0   38 22.67   3  0.07   0.00   0  0.00   0.00   0  0.00   2  3 13  2 79
>    0   38 64.00   1  0.06   0.00   0  0.00   0.00   0  0.00   3  0 18  1 77
>    0   38  0.00   0  0.00   0.00   0  0.00   0.00   0  0.00   0  2 14  1 83

My guess is that your tables all fit in RAM, as you have basically zero
disk accesses.  The orignal poster was seeing heavy disk I/O.

-- 
	Dan Nelson
	dnelson@stripped
Thread
MySQL not using optimum disk throughput.Kevin Burton6 May
  • Re: MySQL not using optimum disk throughput.Dan Nelson7 May
RE: MySQL not using optimum disk throughput.Dathan Pattishall7 May
  • Re: MySQL not using optimum disk throughput.Greg Whalin7 May
    • Re: MySQL not using optimum disk throughput.Kevin Burton7 May
      • Re: MySQL not using optimum disk throughput.Greg Whalin7 May
        • Re: MySQL not using optimum disk throughput.Kevin Burton7 May
          • Re: MySQL not using optimum disk throughput.Kevin Burton7 May
            • Re: MySQL not using optimum disk throughput.Greg Whalin7 May
              • Re: MySQL not using optimum disk throughput.Kevin Burton7 May
                • Re: MySQL not using optimum disk throughput.Atle Veka7 May
                  • Re: MySQL not using optimum disk throughput.Kevin Burton7 May
                    • Re: MySQL not using optimum disk throughput.Atle Veka7 May
                  • Re: MySQL not using optimum disk throughput.Dan Nelson8 May
              • Re: MySQL not using optimum disk throughput.Peter Zaitsev7 May
                • Re: MySQL not using optimum disk throughput.Greg Whalin7 May
                  • Re: MySQL not using optimum disk throughput.Peter Zaitsev1 Jun
                    • RE: MySQL not using optimum disk throughput.Richard Dale1 Jun
        • Re: MySQL not using optimum disk throughput.Kevin Burton9 May
          • Re: MySQL not using optimum disk throughput.Greg Whalin9 May
            • Re: MySQL not using optimum disk throughput.Kevin Burton9 May
              • Re: MySQL not using optimum disk throughput.Greg Whalin9 May
                • Re: MySQL not using optimum disk throughput.Kevin Burton9 May
Re: MySQL not using optimum disk throughput.John David Duncan7 May
  • Re: MySQL not using optimum disk throughput.Peter Zaitsev7 May