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 [[anwenderwiki:server:disk-i-o-testing]] 

Überprüfen der Disk-I/O

Leitfrage: Festplatten, Festplatten-RAIDs, Software-RAIDs oder Hardware-RAIDs - was braucht man für welchen Zweck?

Frage: Hardware oder Software-RAID

Neben der Fragen der Performance, zählt für mich noch das Argument der Wiederherstellung im Disasterfall: Wenn der Hardware-Controller ausfällt braucht man (meines Wissens nach) einen identischen, zumindest gleicher Bauart und neuer RAID-Controller, damit auf dem neuen RAID-Controller die Plattenzusammenstellung wieder erkannt wird. Beim Software-RAID muss man nur einen neuen Computer/Mainboard finden und alle relevanten Platten einen Anschluss finden. Und man würde natürlich auf SATA statt SAS setzen, was es billiger macht und man flexibler ist.

Test zwischen Hard- und Software-RAID 5

Ich teste auf einem System zwei RAID5: einmal 3 Festplatten auf einem Hardware-RAID, einmal 3 Festplatten in einem Software-RAID

Testbedingungen

Eigenschaft Software-RAID Hardware-RAID
Art RAID5 RAID5
controller mdadm (DISKs als JBOD von 3ware durchgereicht) 3ware 9650SE
Anzahl HDDs 3 3
Typ HDDs 3×7200 RPM Barracuda-ES, baugleich 3x7200RPM Barracuda-ES, 2 baugleich, 1 kleiner und älter
Zeit morgens 7 Uhr, nahezu kein Traffic morgens 7 Uhr, nahezu kein Traffic
load im laufenden Betrieb, sonst kein Zugriff im laufenden Betrieb, Zugriff von 5 VMs

Ergebnisse hdparm

Software-RAID
# hdparm -t -T /dev/md/storage

/dev/md/storage:
 Timing cached reads:   17692 MB in  2.00 seconds = 8854.64 MB/sec
 Timing buffered disk reads: 772 MB in  3.01 seconds = 256.84 MB/sec
Hardware-RAID
# hdparm -t -T /dev/sda

/dev/sda:
 Timing cached reads:   17066 MB in  2.00 seconds = 8540.70 MB/sec
 Timing buffered disk reads: 586 MB in  3.00 seconds = 195.14 MB/sec

Ergebnisse fio

# aptitude install fio 
Konfiguration fio

Diese Konfiguration wurde einfach von hier übernommen, ohne nachzudenken, ob das I/O dem des linuxmuster.net Server entspricht oder nicht.

Das directory muss für die jeweilige Konfiguration in einem Verzeichnis auf dem Dateisystem des zu testenden Systems liegen.

# fio --output four-threads-randio.fio.log four-threads-randio.fio 
# fio --output 3ware-four-threads-randio.fio.log 3ware-four-threads-randio.fio

++++ Konfiguration aufklappen |

# cat four-threads-randio.fio
; Four threads, two query, two writers.

[global]
rw=randread
size=256m
directory=./fio-testing-data
ioengine=libaio
iodepth=4
invalidate=1
direct=1

[bgwriter]
rw=randwrite
iodepth=32

[queryA]
iodepth=1
ioengine=mmap
direct=0
thinktime=3

[queryB]
iodepth=1
ioengine=mmap
direct=0
thinktime=5

[bgupdater]
rw=randrw
iodepth=16
thinktime=40
size=32m

++++

Software-RAID

++++ Gesamtes Ergebnis-LOG aufklappen |

# cat four-threads-randio.fio.log

bgwriter: (g=0): rw=randwrite, bs=4K-4K/4K-4K, ioengine=libaio, iodepth=32
queryA: (g=0): rw=randread, bs=4K-4K/4K-4K, ioengine=mmap, iodepth=1
queryB: (g=0): rw=randread, bs=4K-4K/4K-4K, ioengine=mmap, iodepth=1
bgupdater: (g=0): rw=randrw, bs=4K-4K/4K-4K, ioengine=libaio, iodepth=16
fio 1.59
Starting 4 processes

bgwriter: (groupid=0, jobs=1): err= 0: pid=27437
  write: io=262144KB, bw=2263.4KB/s, iops=565 , runt=115822msec
    slat (usec): min=3 , max=118225 , avg=39.25, stdev=1290.65
    clat (usec): min=156 , max=1515.7K, avg=56502.06, stdev=61108.65
     lat (usec): min=163 , max=1515.7K, avg=56541.80, stdev=61120.94
    bw (KB/s) : min=    0, max= 4359, per=83.34%, avg=2002.68, stdev=811.04
  cpu          : usr=0.84%, sys=3.49%, ctx=63684, majf=0, minf=20
  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=0.1%, 32=100.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.1%, 64=0.0%, >=64=0.0%
     issued r/w/d: total=0/65536/0, short=0/0/0
     lat (usec): 250=0.07%, 500=0.73%, 750=0.62%, 1000=0.63%
     lat (msec): 2=2.62%, 4=4.60%, 10=6.84%, 20=8.96%, 50=25.22%
     lat (msec): 100=37.08%, 250=12.07%, 500=0.21%, 750=0.17%, 1000=0.09%
     lat (msec): 2000=0.08%
queryA: (groupid=0, jobs=1): err= 0: pid=27438
  read : io=262144KB, bw=643708 B/s, iops=157 , runt=417014msec
    clat (usec): min=176 , max=200425 , avg=6287.15, stdev=11708.44
     lat (usec): min=176 , max=200425 , avg=6287.50, stdev=11708.43
    bw (KB/s) : min=   42, max= 3548, per=49.00%, avg=635.08, stdev=363.95
  cpu          : usr=0.03%, sys=0.98%, ctx=131137, majf=65536, minf=30
  IO depths    : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued r/w/d: total=65536/0/0, short=0/0/0
     lat (usec): 250=0.93%, 500=17.14%, 750=5.39%, 1000=0.86%
     lat (msec): 2=6.15%, 4=15.67%, 10=46.72%, 20=4.41%, 50=0.99%
     lat (msec): 100=1.34%, 250=0.38%
queryB: (groupid=0, jobs=1): err= 0: pid=27439
  read : io=262144KB, bw=646142 B/s, iops=157 , runt=415443msec
    clat (usec): min=160 , max=271656 , avg=6261.13, stdev=11846.33
     lat (usec): min=160 , max=271657 , avg=6261.49, stdev=11846.33
    bw (KB/s) : min=   37, max= 2801, per=49.59%, avg=642.66, stdev=363.18
  cpu          : usr=0.02%, sys=1.00%, ctx=131139, majf=65536, minf=29
  IO depths    : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued r/w/d: total=65536/0/0, short=0/0/0
     lat (usec): 250=0.75%, 500=17.31%, 750=5.46%, 1000=1.05%
     lat (msec): 2=6.20%, 4=15.78%, 10=46.44%, 20=4.26%, 50=1.01%
     lat (msec): 100=1.32%, 250=0.41%, 500=0.01%
bgupdater: (groupid=0, jobs=1): err= 0: pid=27440
  read : io=16548KB, bw=772410 B/s, iops=188 , runt= 21938msec
    slat (usec): min=6 , max=62538 , avg=30.38, stdev=972.10
    clat (usec): min=150 , max=248703 , avg=34749.50, stdev=34677.60
     lat (usec): min=166 , max=248728 , avg=34780.21, stdev=34677.13
    bw (KB/s) : min=    0, max= 1344, per=53.27%, avg=690.34, stdev=253.09
  write: io=16220KB, bw=757100 B/s, iops=184 , runt= 21938msec
    slat (usec): min=5 , max=67015 , avg=59.93, stdev=1725.22
    clat (usec): min=164 , max=700093 , avg=50753.48, stdev=45899.73
     lat (usec): min=178 , max=700105 , avg=50813.75, stdev=45948.04
    bw (KB/s) : min=  541, max= 1648, per=30.77%, avg=739.43, stdev=174.52
  cpu          : usr=0.51%, sys=1.51%, ctx=14239, majf=0, minf=23
  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=99.8%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.1%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued r/w/d: total=4137/4055/0, short=0/0/0
     lat (usec): 250=0.24%, 500=1.71%, 750=1.28%, 1000=1.27%
     lat (msec): 2=6.07%, 4=8.07%, 10=12.06%, 20=9.80%, 50=20.98%
     lat (msec): 100=29.98%, 250=8.41%, 500=0.09%, 750=0.04%

Run status group 0 (all jobs):
   READ: io=540836KB, aggrb=1296KB/s, minb=643KB/s, maxb=772KB/s, mint=21938msec, maxt=417014msec
  WRITE: io=278364KB, aggrb=2403KB/s, minb=757KB/s, maxb=2317KB/s, mint=21938msec, maxt=115822msec

Disk stats (read/write):
  md127: ios=135165/69672, merge=0/0, ticks=0/0, in_queue=0, util=0.00%, aggrios=68188/46436, aggrmerge=9/32, aggrticks=1253285/593384, aggrin_queue=1846674, aggrutil=66.60%
    sdb: ios=68242/46501, merge=0/43, ticks=1260148/592240, in_queue=1852372, util=66.60%
    sdd: ios=68168/46420, merge=0/41, ticks=1250500/590996, in_queue=1841512, util=66.05%
    sde: ios=68155/46387, merge=28/12, ticks=1249208/596916, in_queue=1846140, util=66.47%

++++

Hardware-RAID

++++ Gesamtes Ergebnis-LOG aufklappen |

# cat 3ware-four-threads-randio.fio.log

bgwriter: (g=0): rw=randwrite, bs=4K-4K/4K-4K, ioengine=libaio, iodepth=32
queryA: (g=0): rw=randread, bs=4K-4K/4K-4K, ioengine=mmap, iodepth=1
queryB: (g=0): rw=randread, bs=4K-4K/4K-4K, ioengine=mmap, iodepth=1
bgupdater: (g=0): rw=randrw, bs=4K-4K/4K-4K, ioengine=libaio, iodepth=16
fio 1.59
Starting 4 processes

bgwriter: (groupid=0, jobs=1): err= 0: pid=4990
  write: io=262144KB, bw=563087 B/s, iops=137 , runt=476721msec
    slat (usec): min=5 , max=3312.1K, avg=682.18, stdev=42345.18
    clat (usec): min=65 , max=8143.4K, avg=231980.82, stdev=861214.70
     lat (usec): min=77 , max=8143.4K, avg=232663.24, stdev=862096.66
    bw (KB/s) : min=    1, max= 3411, per=103.74%, avg=605.85, stdev=659.98
  cpu          : usr=0.02%, sys=0.26%, ctx=60906, majf=0, minf=20
  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=0.1%, 32=100.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.1%, 64=0.0%, >=64=0.0%
     issued r/w/d: total=0/65536/0, short=0/0/0
     lat (usec): 100=0.01%, 500=0.37%, 750=0.32%, 1000=0.32%
     lat (msec): 2=1.32%, 4=85.57%, 10=2.38%, 20=0.72%, 50=0.22%
     lat (msec): 100=0.40%, 250=0.52%, 500=0.30%, 750=0.24%, 1000=0.15%
     lat (msec): 2000=0.68%, >=2000=6.47%
queryA: (groupid=0, jobs=1): err= 0: pid=4991
  read : io=262144KB, bw=315841 B/s, iops=77 , runt=849905msec
    clat (usec): min=65 , max=1146.6K, avg=12892.38, stdev=38584.22
     lat (usec): min=65 , max=1146.6K, avg=12892.73, stdev=38584.22
    bw (KB/s) : min=    5, max= 2142, per=52.53%, avg=334.10, stdev=293.16
  cpu          : usr=0.01%, sys=0.49%, ctx=131093, majf=65536, minf=30
  IO depths    : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued r/w/d: total=65536/0/0, short=0/0/0
     lat (usec): 100=0.74%, 250=5.76%, 500=7.66%, 750=2.81%, 1000=0.64%
     lat (msec): 2=2.88%, 4=12.95%, 10=45.56%, 20=13.32%, 50=3.72%
     lat (msec): 100=1.65%, 250=1.63%, 500=0.60%, 750=0.08%, 1000=0.01%
     lat (msec): 2000=0.01%
queryB: (groupid=0, jobs=1): err= 0: pid=4992
  read : io=262144KB, bw=316713 B/s, iops=77 , runt=847565msec
    clat (usec): min=62 , max=1453.9K, avg=12854.74, stdev=40260.59
     lat (usec): min=62 , max=1453.9K, avg=12855.10, stdev=40260.59
    bw (KB/s) : min=    3, max= 1204, per=53.04%, avg=337.32, stdev=302.66
  cpu          : usr=0.01%, sys=0.48%, ctx=131109, majf=65536, minf=29
  IO depths    : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued r/w/d: total=65536/0/0, short=0/0/0
     lat (usec): 100=0.96%, 250=7.71%, 500=7.86%, 750=2.65%, 1000=0.63%
     lat (msec): 2=2.80%, 4=12.47%, 10=44.34%, 20=13.24%, 50=3.38%
     lat (msec): 100=1.58%, 250=1.69%, 500=0.59%, 750=0.08%, 1000=0.02%
     lat (msec): 2000=0.01%
bgupdater: (groupid=0, jobs=1): err= 0: pid=4993
  read : io=16296KB, bw=81036 B/s, iops=19 , runt=205921msec
    slat (usec): min=7 , max=3201.3K, avg=4739.56, stdev=104796.65
    clat (usec): min=2 , max=2752.5K, avg=98666.26, stdev=215133.50
     lat (usec): min=78 , max=3201.3K, avg=103406.16, stdev=237364.57
    bw (KB/s) : min=    0, max= 5928, per=29.74%, avg=189.14, stdev=623.76
  write: io=16472KB, bw=81911 B/s, iops=19 , runt=205921msec
    slat (usec): min=8 , max=3011.1K, avg=1733.96, stdev=63925.62
    clat (usec): min=65 , max=8140.2K, avg=695273.75, stdev=1395565.63
     lat (usec): min=74 , max=8140.2K, avg=697008.03, stdev=1396181.47
    bw (KB/s) : min=    0, max= 6248, per=34.52%, avg=201.62, stdev=754.72
  cpu          : usr=0.02%, sys=0.15%, ctx=13742, majf=0, minf=23
  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=99.8%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.1%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued r/w/d: total=4074/4118/0, short=0/0/0
     lat (usec): 4=0.06%, 100=7.52%, 250=18.26%, 500=7.17%, 750=1.97%
     lat (usec): 1000=1.00%
     lat (msec): 2=2.25%, 4=8.94%, 10=6.49%, 20=5.70%, 50=7.40%
     lat (msec): 100=6.25%, 250=8.96%, 500=4.14%, 750=1.32%, 1000=0.67%
     lat (msec): 2000=2.94%, >=2000=8.97%

Run status group 0 (all jobs):
   READ: io=540584KB, aggrb=636KB/s, minb=81KB/s, maxb=316KB/s, mint=205921msec, maxt=849905msec
  WRITE: io=278616KB, aggrb=584KB/s, minb=81KB/s, maxb=563KB/s, mint=205921msec, maxt=476721msec

Disk stats (read/write):
  dm-2: ios=135457/71309, merge=0/0, ticks=2052000/18297432, in_queue=20349460, util=100.00%, aggrios=146894/83854, aggrmerge=33536/40266, aggrticks=2219656/22239272, aggrin_queue=24461388, aggrutil=100.00%
    sda: ios=146894/83854, merge=33536/40266, ticks=2219656/22239272, in_queue=24461388, util=100.00%

++++

Unterschiede anzeigen

Links: Hardware-RAID, Rechts: Software-RAID ++++ Unterschiede komplett aufklappen |

diff -y *.log | less -S
bgwriter: (g=0): rw=randwrite, bs=4K-4K/4K-4K, ioengine=libai   bgwriter: (g=0): rw=randwrite, bs=4K-4K/4K-4K, ioengine=libai
queryA: (g=0): rw=randread, bs=4K-4K/4K-4K, ioengine=mmap, io   queryA: (g=0): rw=randread, bs=4K-4K/4K-4K, ioengine=mmap, io
queryB: (g=0): rw=randread, bs=4K-4K/4K-4K, ioengine=mmap, io   queryB: (g=0): rw=randread, bs=4K-4K/4K-4K, ioengine=mmap, io
bgupdater: (g=0): rw=randrw, bs=4K-4K/4K-4K, ioengine=libaio,   bgupdater: (g=0): rw=randrw, bs=4K-4K/4K-4K, ioengine=libaio,
fio 1.59                                                        fio 1.59
Starting 4 processes                                            Starting 4 processes

bgwriter: (groupid=0, jobs=1): err= 0: pid=4990               | bgwriter: (groupid=0, jobs=1): err= 0: pid=27437
  write: io=262144KB, bw=563087 B/s, iops=137 , runt=476721ms |   write: io=262144KB, bw=2263.4KB/s, iops=565 , runt=115822ms
    slat (usec): min=5 , max=3312.1K, avg=682.18, stdev=42345 |     slat (usec): min=3 , max=118225 , avg=39.25, stdev=1290.6
    clat (usec): min=65 , max=8143.4K, avg=231980.82, stdev=8 |     clat (usec): min=156 , max=1515.7K, avg=56502.06, stdev=6
     lat (usec): min=77 , max=8143.4K, avg=232663.24, stdev=8 |      lat (usec): min=163 , max=1515.7K, avg=56541.80, stdev=6
    bw (KB/s) : min=    1, max= 3411, per=103.74%, avg=605.85 |     bw (KB/s) : min=    0, max= 4359, per=83.34%, avg=2002.68
  cpu          : usr=0.02%, sys=0.26%, ctx=60906, majf=0, min |   cpu          : usr=0.84%, sys=3.49%, ctx=63684, majf=0, min
  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=0.1%, 32=     IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=0.1%, 32=
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%,         submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.1%,         complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.1%, 
     issued r/w/d: total=0/65536/0, short=0/0/0                      issued r/w/d: total=0/65536/0, short=0/0/0
     lat (usec): 100=0.01%, 500=0.37%, 750=0.32%, 1000=0.32%  |      lat (usec): 250=0.07%, 500=0.73%, 750=0.62%, 1000=0.63%
     lat (msec): 2=1.32%, 4=85.57%, 10=2.38%, 20=0.72%, 50=0. |      lat (msec): 2=2.62%, 4=4.60%, 10=6.84%, 20=8.96%, 50=25.
     lat (msec): 100=0.40%, 250=0.52%, 500=0.30%, 750=0.24%,  |      lat (msec): 100=37.08%, 250=12.07%, 500=0.21%, 750=0.17%
     lat (msec): 2000=0.68%, >=2000=6.47%                     |      lat (msec): 2000=0.08%
queryA: (groupid=0, jobs=1): err= 0: pid=4991                 | queryA: (groupid=0, jobs=1): err= 0: pid=27438
  read : io=262144KB, bw=315841 B/s, iops=77 , runt=849905mse |   read : io=262144KB, bw=643708 B/s, iops=157 , runt=417014ms
    clat (usec): min=65 , max=1146.6K, avg=12892.38, stdev=38 |     clat (usec): min=176 , max=200425 , avg=6287.15, stdev=11
     lat (usec): min=65 , max=1146.6K, avg=12892.73, stdev=38 |      lat (usec): min=176 , max=200425 , avg=6287.50, stdev=11
    bw (KB/s) : min=    5, max= 2142, per=52.53%, avg=334.10, |     bw (KB/s) : min=   42, max= 3548, per=49.00%, avg=635.08,
  cpu          : usr=0.01%, sys=0.49%, ctx=131093, majf=65536 |   cpu          : usr=0.03%, sys=0.98%, ctx=131137, majf=65536
  IO depths    : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 3     IO depths    : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 3
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%,         submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%,         complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 
     issued r/w/d: total=65536/0/0, short=0/0/0                      issued r/w/d: total=65536/0/0, short=0/0/0
     lat (usec): 100=0.74%, 250=5.76%, 500=7.66%, 750=2.81%,  |      lat (usec): 250=0.93%, 500=17.14%, 750=5.39%, 1000=0.86%
     lat (msec): 2=2.88%, 4=12.95%, 10=45.56%, 20=13.32%, 50= |      lat (msec): 2=6.15%, 4=15.67%, 10=46.72%, 20=4.41%, 50=0
     lat (msec): 100=1.65%, 250=1.63%, 500=0.60%, 750=0.08%,  |      lat (msec): 100=1.34%, 250=0.38%
     lat (msec): 2000=0.01%                                   | queryB: (groupid=0, jobs=1): err= 0: pid=27439
queryB: (groupid=0, jobs=1): err= 0: pid=4992                 |   read : io=262144KB, bw=646142 B/s, iops=157 , runt=415443ms
  read : io=262144KB, bw=316713 B/s, iops=77 , runt=847565mse |     clat (usec): min=160 , max=271656 , avg=6261.13, stdev=11
    clat (usec): min=62 , max=1453.9K, avg=12854.74, stdev=40 |      lat (usec): min=160 , max=271657 , avg=6261.49, stdev=11
     lat (usec): min=62 , max=1453.9K, avg=12855.10, stdev=40 |     bw (KB/s) : min=   37, max= 2801, per=49.59%, avg=642.66,
    bw (KB/s) : min=    3, max= 1204, per=53.04%, avg=337.32, |   cpu          : usr=0.02%, sys=1.00%, ctx=131139, majf=65536
  cpu          : usr=0.01%, sys=0.48%, ctx=131109, majf=65536 <
  IO depths    : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 3     IO depths    : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 3
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%,         submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%,         complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 
     issued r/w/d: total=65536/0/0, short=0/0/0                      issued r/w/d: total=65536/0/0, short=0/0/0
     lat (usec): 100=0.96%, 250=7.71%, 500=7.86%, 750=2.65%,  |      lat (usec): 250=0.75%, 500=17.31%, 750=5.46%, 1000=1.05%
     lat (msec): 2=2.80%, 4=12.47%, 10=44.34%, 20=13.24%, 50= |      lat (msec): 2=6.20%, 4=15.78%, 10=46.44%, 20=4.26%, 50=1
     lat (msec): 100=1.58%, 250=1.69%, 500=0.59%, 750=0.08%,  |      lat (msec): 100=1.32%, 250=0.41%, 500=0.01%
     lat (msec): 2000=0.01%                                   | bgupdater: (groupid=0, jobs=1): err= 0: pid=27440
bgupdater: (groupid=0, jobs=1): err= 0: pid=4993              |   read : io=16548KB, bw=772410 B/s, iops=188 , runt= 21938mse
  read : io=16296KB, bw=81036 B/s, iops=19 , runt=205921msec  |     slat (usec): min=6 , max=62538 , avg=30.38, stdev=972.10
    slat (usec): min=7 , max=3201.3K, avg=4739.56, stdev=1047 |     clat (usec): min=150 , max=248703 , avg=34749.50, stdev=3
    clat (usec): min=2 , max=2752.5K, avg=98666.26, stdev=215 |      lat (usec): min=166 , max=248728 , avg=34780.21, stdev=3
     lat (usec): min=78 , max=3201.3K, avg=103406.16, stdev=2 |     bw (KB/s) : min=    0, max= 1344, per=53.27%, avg=690.34,
    bw (KB/s) : min=    0, max= 5928, per=29.74%, avg=189.14, |   write: io=16220KB, bw=757100 B/s, iops=184 , runt= 21938mse
  write: io=16472KB, bw=81911 B/s, iops=19 , runt=205921msec  |     slat (usec): min=5 , max=67015 , avg=59.93, stdev=1725.22
    slat (usec): min=8 , max=3011.1K, avg=1733.96, stdev=6392 |     clat (usec): min=164 , max=700093 , avg=50753.48, stdev=4
    clat (usec): min=65 , max=8140.2K, avg=695273.75, stdev=1 |      lat (usec): min=178 , max=700105 , avg=50813.75, stdev=4
     lat (usec): min=74 , max=8140.2K, avg=697008.03, stdev=1 |     bw (KB/s) : min=  541, max= 1648, per=30.77%, avg=739.43,
    bw (KB/s) : min=    0, max= 6248, per=34.52%, avg=201.62, |   cpu          : usr=0.51%, sys=1.51%, ctx=14239, majf=0, min
  cpu          : usr=0.02%, sys=0.15%, ctx=13742, majf=0, min <
  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=99.8%, 32     IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=99.8%, 32
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%,         submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.1%, 32=0.0%,         complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.1%, 32=0.0%, 
     issued r/w/d: total=4074/4118/0, short=0/0/0             |      issued r/w/d: total=4137/4055/0, short=0/0/0
     lat (usec): 4=0.06%, 100=7.52%, 250=18.26%, 500=7.17%, 7 |      lat (usec): 250=0.24%, 500=1.71%, 750=1.28%, 1000=1.27%
     lat (usec): 1000=1.00%                                   |      lat (msec): 2=6.07%, 4=8.07%, 10=12.06%, 20=9.80%, 50=20
     lat (msec): 2=2.25%, 4=8.94%, 10=6.49%, 20=5.70%, 50=7.4 |      lat (msec): 100=29.98%, 250=8.41%, 500=0.09%, 750=0.04%
     lat (msec): 100=6.25%, 250=8.96%, 500=4.14%, 750=1.32%,  <
     lat (msec): 2000=2.94%, >=2000=8.97%                     <

Run status group 0 (all jobs):                                  Run status group 0 (all jobs):
   READ: io=540584KB, aggrb=636KB/s, minb=81KB/s, maxb=316KB/ |    READ: io=540836KB, aggrb=1296KB/s, minb=643KB/s, maxb=772K
  WRITE: io=278616KB, aggrb=584KB/s, minb=81KB/s, maxb=563KB/ |   WRITE: io=278364KB, aggrb=2403KB/s, minb=757KB/s, maxb=2317

Disk stats (read/write):                                        Disk stats (read/write):
  dm-2: ios=135457/71309, merge=0/0, ticks=2052000/18297432,  |   md127: ios=135165/69672, merge=0/0, ticks=0/0, in_queue=0, 
    sda: ios=146894/83854, merge=33536/40266, ticks=2219656/2 |     sdb: ios=68242/46501, merge=0/43, ticks=1260148/592240, i
                                                              >     sdd: ios=68168/46420, merge=0/41, ticks=1250500/590996, i
                                                              >     sde: ios=68155/46387, merge=28/12, ticks=1249208/596916, 

++++

Fazit aus der Sicht des Software-RAIDs

  • Schreibprozesse haben höhere Latenz, kleineren maximalen Schreibdurchsatz, aber größeren Durchsatz im Schnitt
  • Leseprozesse haben ähnliche Latenz, deutlich kleineren maximalen Lesedurchsatz, aber größeren Durchsatz im Schnitt
  • Updateprozsse haben ähnliche Latenz, kleineren maximalen Durchsatz, größeren Durchsatz im Schnitt

Man kann auch andere ERgebnisse herauslesen, wenn man nur die Durchschnittswerte liest. Dann hat auch bei der Latenz das Software-RAID die Nase vorn.

Die CPU-Last ist beim Software-RAID immer höher:

  • Schreiben: 3,5% vs. 0,3%
  • Lesen: 1% vs. 0,5%
  • update: 1,5% vs. 0,15%
 [[anwenderwiki:server:disk-i-o-testing]] anwenderwiki/server/disk-i-o-testing.txt · Zuletzt geändert: 2016/03/08 09:52 (Externe Bearbeitung)