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Date:      Mon, 8 Jan 2007 16:10:19 -0500
From:      "Ahnjoan Amous" <ahnjoan@gmail.com>
To:        freebsd-geom@freebsd.org
Subject:   =?windows-1252?q?GEOM_mirror_performance_=96_slow?=
Message-ID:  <5e575c8a0701081310h4d59c6f7k31c5e31de9933754@mail.gmail.com>

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While deploying 6.1-RELEASE I'm seeing slower than expected speed
using geom mirror.

Test 1.  Outside of GEOM I'm able to write to both aacd2 and
aacd3 concurrently and achieve between 41M =96 45M a second write
speeds. (around 75M a second if I run the commands separately)

Test 2. Inside a GEOM container but not mirrored (aacd2 =3D gm2,
aacd3 =3D gm3) I'm able to write to both gm2 and gm3 concurrently
and achieve between 40M =96 49M a second write speeds. (around 75M
a second if I run the commands separately)

Test 3. Inside a GEOM mirror (gm1 =3D aacd2 =3D aacd3) I'm able to
achieve 23M a second.

I'd love someones opinion as to if the speed I'm seeing using
GEOM mirror is to be expected.

FYI =96 The mirror was manually rebuilt and COMPLETE before tests
were attempted on the mirror.

***********************************************************************
*** Test 1.
*** dd to devices mounted outside of geom

> dd if=3D/dev/zero of=3D/data02/helloworld bs=3D8k count=3D100k &
> dd if=3D/dev/zero of=3D/data03/helloworld bs=3D8k count=3D100k &
    838860800 bytes transferred in 18.799345 secs (44621810 bytes/sec)
                                                   ^^^^^^^^
    838860800 bytes transferred in 18.544963 secs (45233889 bytes/sec)
                                                   ^^^^^^^^
> dd if=3D/dev/zero of=3D/data02/helloworld bs=3D1m count=3D800 &
> dd if=3D/dev/zero of=3D/data03/helloworld bs=3D1m count=3D800 &
    838860800 bytes transferred in 20.014247 secs (41913183 bytes/sec)
                                                   ^^^^^^^^
    838860800 bytes transferred in 19.824656 secs (42314016 bytes/sec)
                                                   ^^^^^^^^

    **** setup info for test ****
    > df -k
        /dev/aacd2s1e   2026030 819620 1044328    44%    /data02
        /dev/aacd3s1e   2026030 819620 1044328    44%    /data03

***********************************************************************
*** Test 2.
*** dd to devices mounted as their own geom volumes

> dd if=3D/dev/zero of=3D/data02/helloworld bs=3D8k count=3D100k &
> dd if=3D/dev/zero of=3D/data03/helloworld bs=3D8k count=3D100k &
    838860800 bytes transferred in 17.118679 secs (49002659 bytes/sec)
                                                   ^^^^^^^^
    838860800 bytes transferred in 16.810787 secs (49900150 bytes/sec)
                                                   ^^^^^^^^
> dd if=3D/dev/zero of=3D/data02/helloworld bs=3D1m count=3D800 &
> dd if=3D/dev/zero of=3D/data03/helloworld bs=3D1m count=3D800 &
    838860800 bytes transferred in 20.907455 secs (40122569 bytes/sec)
                                                   ^^^^^^^^
    838860800 bytes transferred in 20.638277 secs (40645874 bytes/sec)
                                                   ^^^^^^^^

    **** setup info for test ****
    > df -k
        /dev/mirror/gm2   2026030 819620 1044328    44%    /data02
        /dev/mirror/gm3   2026030 819620 1044328    44%    /data03
    > gmirror list
        Geom name: gm2
          1. Name: aacd2s1e
        Geom name: gm3
          1. Name: aacd3s1e

***********************************************************************
*** Test 3.
*** dd to devices mounted as a geom mirror

> dd if=3D/dev/zero of=3D/data01/helloworld bs=3D8k count=3D100k
    838860800 bytes transferred in 35.622392 secs (23548694 bytes/sec)
                                                   ^^^^^^^^
> dd if=3D/dev/zero of=3D/data01/helloworld bs=3D1m count=3D800
    838860800 bytes transferred in 35.588491 secs (23571126 bytes/sec)
                                                   ^^^^^^^^

    **** setup info for test ****
    > df -k
        /dev/mirror/gm1   2026028 819620 1044326    44%    /data01
    > gmirror list
        Geom name: gm1
          1. Name: aacd2s1e
          2. Name: aacd3s1e



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