[plamo:21850] Re: RAID の構築に際して

[Seitarou Sugawara]

皆さん、こんにちは。
Software RAID1の続きです。

linux/drivers/md/md.cのコメントにこんなことが書いてあります。raidの再
構築のスピードは/proc/sys/dev/dev/raid/speed_limit_m{ax,in}で設定でき
ると。

/*
 * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
 * is 100 KB/sec, so the extra system load does not show up that much.
 * Increase it if you want to have more _guaranteed_ speed. Note that
 * the RAID driver will use the maximum available bandwith if the IO
 * subsystem is idle. There is also an 'absolute maximum'
reconstruction
 * speed limit - in case reconstruction slows down your system despite
 * idle IO detection.
 *
 * you can change it via /proc/sys/dev/raid/speed_limit_min and _max.
 */

ハードスペックは次のとおりです。

# hdparm -Tt /dev/md1

/dev/md1:
 Timing buffer-cache reads:   128 MB in  1.50 seconds = 85.33 MB/sec
 Timing buffered disk reads:  64 MB in  1.69 seconds = 37.87 MB/sec

# cat /proc/ide/hda/model
ST380021A

# cat /proc/sys/dev/raid/speed_limit_m{ax,in}
100000
100

# lspci
00:00.0 Host bridge: Intel Corp. 82815 815 Chipset Host Bridge and
Memory Controller Hub (rev 04)
00:02.0 VGA compatible controller: Intel Corp. 82815 CGC [Chipset
Graphics Controller] (rev 04)
00:1e.0 PCI bridge: Intel Corp. 82801BA/CA/DB/EB PCI Bridge (rev 05)
00:1f.0 ISA bridge: Intel Corp. 82801BA ISA Bridge (LPC) (rev 05)
00:1f.1 IDE interface: Intel Corp. 82801BA IDE U100 (rev 05)
00:1f.2 USB Controller: Intel Corp. 82801BA/BAM USB (Hub  (rev 05)
00:1f.3 SMBus: Intel Corp. 82801BA/BAM SMBus (rev 05)
00:1f.4 USB Controller: Intel Corp. 82801BA/BAM USB (Hub  (rev 05)
00:1f.5 Multimedia audio controller: Intel Corp. 82801BA/BAM AC'97
Audio (rev 05)
01:02.0 Ethernet controller: 3Com Corporation 3c905C-TX/TX-M [Tornado]
(rev 78)

菅原