Date: Wed, 28 Mar 2007 15:02:45 +0200 From: =?iso-8859-1?B?U3phYvMgUOl0ZXI=?= <matyee@mail.alba.hu> To: <freebsd-geom@freebsd.org> Subject: Re: raid3 is slow Message-ID: <008701c77139$613694b0$6502a8c0@peteruj> References: <003401c7712a$f71ebb60$6502a8c0@peteruj> <eudlg8$pm4$1@sea.gmane.org><005c01c77134$28e0fce0$6502a8c0@peteruj> <460A6139.4040401@freebsd.org>
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I stop the copy
#diskinfo -vt /dev/raid3/nmivol
/dev/raid3/nmivol
2048 # sectorsize
638906845184 # mediasize in bytes (595G)
311966233 # mediasize in sectors
Seek times:
Full stroke: 250 iter in 11.486148 sec = 45.945 msec
Half stroke: 250 iter in 8.818982 sec = 35.276 msec
Quarter stroke: 500 iter in 15.365682 sec = 30.731 msec
Short forward: 400 iter in 6.013585 sec = 15.034 msec
Short backward: 400 iter in 10.356176 sec = 25.890 msec
Seq outer: 2048 iter in 0.803544 sec = 0.392 msec
Seq inner: 2048 iter in 0.804926 sec = 0.393 msec
Transfer rates:
outside: 102400 kbytes in 1.179933 sec = 86785 kbytes/sec
middle: 102400 kbytes in 1.148816 sec = 89135 kbytes/sec
inside: 102400 kbytes in 1.171987 sec = 87373 kbytes/sec
#diskinfo -vt /dev/label/nmivol1
/dev/label/nmivol1
512 # sectorsize
159726711808 # mediasize in bytes (149G)
311966234 # mediasize in sectors
309490 # Cylinders according to firmware.
16 # Heads according to firmware.
63 # Sectors according to firmware.
Seek times:
Full stroke: 250 iter in 5.540328 sec = 22.161 msec
Half stroke: 250 iter in 3.955182 sec = 15.821 msec
Quarter stroke: 500 iter in 6.648877 sec = 13.298 msec
Short forward: 400 iter in 2.203517 sec = 5.509 msec
Short backward: 400 iter in 1.960238 sec = 4.901 msec
Seq outer: 2048 iter in 0.288225 sec = 0.141 msec
Seq inner: 2048 iter in 0.292780 sec = 0.143 msec
Transfer rates:
outside: 102400 kbytes in 1.839020 sec = 55682 kbytes/sec
middle: 102400 kbytes in 2.112483 sec = 48474 kbytes/sec
inside: 102400 kbytes in 3.416896 sec = 29969 kbytes/sec
# atacontrol mode ad0
current mode = UDMA100
# atacontrol mode ad1
current mode = UDMA100
# atacontrol mode ad2
current mode = UDMA100
# atacontrol mode ad3
current mode = UDMA100
# atacontrol mode ad6
current mode = SATA150
gstripe may help, and extends disk space, but less secure.
#dd if=/dev/zero of=/mnt/new/x.x bs=1m count=128
128+0 records in
128+0 records out
134217728 bytes transferred in 11.410957 secs (11762180 bytes/sec)
Matyee
----- Original Message -----
From: "Eric Anderson" <anderson@freebsd.org>
On 03/28/07 07:25, Szabó Péter wrote:
> Yes, consumers are the disks.
[..snip..]
> #systat -vmstat
>
> 4 users Load 1.62 1.75 1.82 Mar 28 14:24
>
> Mem:KB REAL VIRTUAL VN PAGER SWAP PAGER
> Tot Share Tot Share Free in out in out
> Act 66488 6968 150740 11396 31172 count
> All 1017076 10160975701764 16256 pages
> 1 zfod
> Interrupts
> Proc:r p d s w Csw Trp Sys Int Sof Flt cow 4066
> total
> 1 60 9820 68312106 4237 752 1 195968 wire 1002 0:
> clk
> 79088 act 128 8:
> rtc
> 89.2%Sys 3.0%Intr 3.3%User 0.0%Nice 4.5%Idl 714076 inact 10 10:
> fxp
> | | | | | | | | | | 29068 cache 1780 11:
> ata
> =============================================+>> 2104 free 573 14:
> ata
> 12 daefr 573 15:
> ata
> Namei Name-cache Dir-cache prcfr
> Calls hits % hits % react
> 11 10 91 1 pdwake
> 4045 pdpgs
> Disks ad0 ad1 ad2 ad3 ad6 intrn
> KB/t 8.42 8.42 8.42 8.42 5.67 113904 buf
> tps 287 287 287 287 1780 133 dirtybuf
> MB/s 2.36 2.36 2.36 2.36 9.85 69984 desiredvnodes
> % busy 25 26 24 26 99 21586 numvnodes
> 17495 freevnodes
>
> I use mc to copy.
>
> Matyee
Can you send the output of:
diskinfo -vt /dev/raid3/nmivol
diskinfo -vt /dev/label/nmivol1
Thanks
Eric
>> Szabó Péter wrote:
>>
>>> I have a raid3 setup with 5 consumers. it seems everything is all right,
>>> but riad is very slow imho, but i don't have any >reference.
>> You need to give more accurate information. What are the "consumers" you
>> mention? Maybe you mean the disks/components of the RAID?
>>
>>> Now i copy from raid3 to a single hdd 75GB data. Nothing else run,
>>> except ssh, and ftp. Before the copy my load is >0.1, after i star the
>>> copy the load is 2.92 or higher, and the machine is very slow. I think
>>> this is not normal, or is it?
>>> Copy how? By "cp" from shell?
>>> My config is:
>>> AMD Barton 2500+ with 1GB memory.
>>>
>>> I stop the copy, load is 0.05, and start again, after a few seconds load
>>> is 2.02.
>
>> Due to the way raid3 works, it's by definition more CPU-intensive than
>> most other RAID levels, but it shouldn't be even remotely slow as that.
>> Also, since your load is > 2, what are the other CPU intensive tasks?
>
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