cpu consumption

Hello Everybody

I have checked the list archive but I could not find any message that
help. So I'm asking for help here. I have a Sun storege with 12 sata hard disks connected to a normal PC using a QLogic ISP2300 host adapter card. I have configured 6 raid1, (2 hard disk each). I excecuted the following commands to create all of the them

mdadm --create --verbose /dev/md1 --level=raid1 --raid-devices=2 /dev/sda /dev/sdb
mdadm --create --verbose /dev/md2 --level=raid1 --raid-devices=2 /dev/sdc /dev/sdd
mdadm --create --verbose /dev/md3 --level=raid1 --raid-devices=2 /dev/sde /dev/sdf
mdadm --create --verbose /dev/md4 --level=raid1 --raid-devices=2 /dev/sdg /dev/sdh
mdadm --create --verbose /dev/md5 --level=raid1 --raid-devices=2 /dev/sdi /dev/sdj
mdadm --create --verbose /dev/md6 --level=raid1 --raid-devices=2 /dev/sdk /dev/sdl

Here is my /etc/mdadm/mdadm.conf file

DEVICE /dev/sd[abcdefghijkl] /dev/md1 /dev/md2 /dev/md3 /dev/md4 /dev/md5 /dev/md6
ARRAY /dev/md1 devices=/dev/sda,/dev/sdb
ARRAY /dev/md2 devices=/dev/sdc,/dev/sdd
ARRAY /dev/md3 devices=/dev/sde,/dev/sdf
ARRAY /dev/md4 devices=/dev/sdg,/dev/sdh
ARRAY /dev/md5 devices=/dev/sdi,/dev/sdj
ARRAY /dev/md6 devices=/dev/sdk,/dev/sdl

The problem is that the following proccesses are using a lot of cpu
time.

    md1_raid1
    md1_resync
    ......
    md6_raid1
    md6_resync

    Here is a sample of the uptime command

17:54:16 up 5:48, 2 users, load average: 5.02, 5.05, 5.26

Does anybody have an idea what is the problem? Thank a lot in advance

Best regards
Gilberto Diaz

to me, it looks like the "problem" is that the RAID system is still creating the array and syncing all the partitions up. Once it's finished your system will be idle.

I bet it's stopped doing it by the time you get this email... What does the output of

cat /proc/mdstat

look like?

Gordon

Thanks Gordon, Guy, Michel and Neil, your advises were very useful.

Gordon was right, all raids are still syncing (Bellow part of the
/proc/mdstat file). Guy you were right too, the command "uptime" does not display the cpu load directly, sorry about that.

Best regards
Gilberto

----------------------------------------------------------------------------------------------------------------------------------------------------
Personalities : [linear] [raid0] [raid1] [raid5] [multipath] [raid6] [raid10] [faulty]

md6 : active raid1 sdk[0] sdl[1]

      244190144 blocks [2/2] [UU]
      [================>....]  resync = 83.4% (203849152/244190144)

finish=5.0min spee
d=131933K/sec

md5 : active raid1 sdi[0] sdj[1]

      244190144 blocks [2/2] [UU]
      [================>....]  resync = 83.8% (204684480/244190144)

finish=5.1min spee
d=127124K/sec

.
.
.

--------------------------------------------------------------------------------------------------------------------------------------------------------------

} -----Original Message-----
} From: [email protected] [mailto:linux-raid- } [email protected]] On Behalf Of Gilberto Diaz
} Sent: Monday, January 23, 2006 5:28 PM
} To: [email protected]
} Subject: cpu consumption
}
} Hello Everybody
}
} I have checked the list archive but I could not find any message that
} help. So I'm asking for help here. I have a Sun storege with 12 sata } hard disks connected to a normal PC using a QLogic ISP2300 host adapter } card. I have configured 6 raid1, (2 hard disk each). I excecuted the } following commands to create all of the them
}
} mdadm --create --verbose /dev/md1 --level=raid1 --raid-devices=2 } /dev/sda /dev/sdb
} mdadm --create --verbose /dev/md2 --level=raid1 --raid-devices=2 } /dev/sdc /dev/sdd
} mdadm --create --verbose /dev/md3 --level=raid1 --raid-devices=2 } /dev/sde /dev/sdf
} mdadm --create --verbose /dev/md4 --level=raid1 --raid-devices=2 } /dev/sdg /dev/sdh
} mdadm --create --verbose /dev/md5 --level=raid1 --raid-devices=2 } /dev/sdi /dev/sdj
} mdadm --create --verbose /dev/md6 --level=raid1 --raid-devices=2 } /dev/sdk /dev/sdl
}
} Here is my /etc/mdadm/mdadm.conf file
}
} DEVICE /dev/sd[abcdefghijkl] /dev/md1 /dev/md2 /dev/md3 /dev/md4 } /dev/md5 /dev/md6
} ARRAY /dev/md1 devices=/dev/sda,/dev/sdb
} ARRAY /dev/md2 devices=/dev/sdc,/dev/sdd
} ARRAY /dev/md3 devices=/dev/sde,/dev/sdf
} ARRAY /dev/md4 devices=/dev/sdg,/dev/sdh
} ARRAY /dev/md5 devices=/dev/sdi,/dev/sdj
} ARRAY /dev/md6 devices=/dev/sdk,/dev/sdl
}
} The problem is that the following proccesses are using a lot of cpu
} time.
}

}     md1_raid1
}     md1_resync
}     ......
}     md6_raid1
}     md6_resync

}
} Here is a sample of the uptime command
}
} 17:54:16 up 5:48, 2 users, load average: 5.02, 5.05, 5.26

What is the CPU load? The above does not reflect CPU usage. I beleve it reports on average outsanding IOs. With 6 arrays syncing, I would have expected 6 or 12.

Run "top", or "sar -u 10 10" to see CPU usage.

Guy
}
} Does anybody have an idea what is the problem? Thank a lot in advance
}
} Best regards
} Gilberto Diaz
} -
} To unsubscribe from this list: send the line "unsubscribe linux-raid" in } the body of a message to [email protected]
} More majordomo info at http://vger.kernel.org/majordomo-info.html

This is a poor choice for an mdadm.conf file.
The device names of 'SCSI' devices are prone to change with changing system configuration. If something disappears or is added, all the names could change, and this will cease to work.
I would strongly recommend putting UUIDs in there.

echo 'DEVICE /dev/sd[a-l]' > /etc/mdadm/mdadm.conf mdadm -Ds | grep -v devices >> /etc/mdadm/mdadm.conf

NeilBrown

This last line gives nothing because -v switch selects lines not having devices, but the other line has num-devices which also matches:
ie

C1:~# mdadm -Ds
ARRAY /dev/md3 level=raid1 num-devices=2 
UUID=209ab7c8:d37fee49:3a63af71:99193e75
   devices=/dev/sde1
ARRAY /dev/md2 level=raid1 num-devices=2 
UUID=03dc44fa:606063e2:83e69037:50d00eb5
   devices=/dev/sdd1
ARRAY /dev/md1 level=raid1 num-devices=2 
UUID=88433668:ffa6265d:5ed3569b:9ef1d0f8
   devices=/dev/sdc1
ARRAY /dev/md0 level=raid1 num-devices=2 
UUID=5f001583:253365c1:1092ccdf:b052e938
   devices=/dev/sdb1,/dev/sda1

thus

C1:~# mdadm -Ds|grep -v devices
C1:~#   

while you must want

C1:~# mdadm -Ds |grep  num-devices
ARRAY /dev/md3 level=raid1 num-devices=2 
UUID=209ab7c8:d37fee49:3a63af71:99193e75
ARRAY /dev/md2 level=raid1 num-devices=2 
UUID=03dc44fa:606063e2:83e69037:50d00eb5
ARRAY /dev/md1 level=raid1 num-devices=2 
UUID=88433668:ffa6265d:5ed3569b:9ef1d0f8
ARRAY /dev/md0 level=raid1 num-devices=2 
UUID=5f001583:253365c1:1092ccdf:b052e938

(excuse the line wrap by kmail)

thanks
Mitchell Laks