りおてくでタグ「RAID」が付けられているもの
某誌の原稿で採用されなかった説明だけれど、個人的にはやってみて面白かったので。
4KのチャンクでRAIDしておいて、そこに4095バイトのデータをファイルに書き込むと終端子と合わせてちょうど4Kになるから、それをRAIDデバイスに書き込んでからhexdumpしたら、そのまま見えるんじゃないかと考えた。ただし、ファイルシステムはext2にして他のプロセスが書き込まないこととか、noatime付けておくとか、そういったことはちゃんと考慮すること。
4キロバイトのチャンクサイズとレイアウトにleft-symmetricを指定して、RAID 5を作成
# mdadm --create --auto=yes /dev/md2 --level=5 --layout=ls --chunk=4 --raid-devices=3 /dev/sdc1 /dev/sdd1 /dev/sde1
4キロバイトの"1"だけを含むファイルを作成するコマンド例
# for i in `seq 1 4095`; do buf=$buf"1" ; done ;echo $buf > file_1
[/dev/sdc1] 04100000 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 |................| * 04100ff0 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 00 |................| 04101000 33 33 33 33 33 33 33 33 33 33 33 33 33 33 33 33 |3333333333333333| * 04101ff0 33 33 33 33 33 33 33 33 33 33 33 33 33 33 33 0a |333333333333333.| 04102000 36 36 36 36 36 36 36 36 36 36 36 36 36 36 36 36 |6666666666666666| * 04102ff0 36 36 36 36 36 36 36 36 36 36 36 36 36 36 36 0a |666666666666666.| 04103000 0f 0f 0f 0f 0f 0f 0f 0f 0f 0f 0f 0f 0f 0f 0f 0f |................| * 04103ff0 0f 0f 0f 0f 0f 0f 0f 0f 0f 0f 0f 0f 0f 0f 0f 00 |................| [/dev/sdd1] 04100000 31 31 31 31 31 31 31 31 31 31 31 31 31 31 31 31 |1111111111111111| * 04100ff0 31 31 31 31 31 31 31 31 31 31 31 31 31 31 31 0a |111111111111111.| 04101000 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 |4444444444444444| * 04101ff0 34 34 34 34 34 34 34 34 34 34 34 34 34 34 34 0a |444444444444444.| 04102000 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 |................| * 04102ff0 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 00 |................| 04103000 37 37 37 37 37 37 37 37 37 37 37 37 37 37 37 37 |7777777777777777| * 04103ff0 37 37 37 37 37 37 37 37 37 37 37 37 37 37 37 0a |777777777777777.| [/dev/sde1] 04100000 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 |2222222222222222| * 04100ff0 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 0a |222222222222222.| 04101000 07 07 07 07 07 07 07 07 07 07 07 07 07 07 07 07 |................| * 04101ff0 07 07 07 07 07 07 07 07 07 07 07 07 07 07 07 00 |................| 04102000 35 35 35 35 35 35 35 35 35 35 35 35 35 35 35 35 |5555555555555555| * 04102ff0 35 35 35 35 35 35 35 35 35 35 35 35 35 35 35 0a |555555555555555.| 04103000 38 38 38 38 38 38 38 38 38 38 38 38 38 38 38 38 |8888888888888888| * 04103ff0 38 38 38 38 38 38 38 38 38 38 38 38 38 38 38 0a |888888888888888.|
ICH10R入りM/Bに1TBのHDD２発なので、お決まりのやつを(^^ゞ
なんだかdmraidのパッケージにはあまり情報が無くて、まあ実際こんな感じなんだが。ちょっと投げやりすぐる...。
# rpm -ql dmraid /sbin/dmraid /sbin/dmraid.static /usr/lib64/libdmraid.so.1.0.0.rc13 /usr/share/doc/dmraid-1.0.0.rc13 /usr/share/doc/dmraid-1.0.0.rc13/CHANGELOG /usr/share/doc/dmraid-1.0.0.rc13/CREDITS /usr/share/doc/dmraid-1.0.0.rc13/KNOWN_BUGS /usr/share/doc/dmraid-1.0.0.rc13/LICENSE /usr/share/doc/dmraid-1.0.0.rc13/LICENSE_GPL /usr/share/doc/dmraid-1.0.0.rc13/LICENSE_LGPL /usr/share/doc/dmraid-1.0.0.rc13/README /usr/share/doc/dmraid-1.0.0.rc13/TODO /usr/share/doc/dmraid-1.0.0.rc13/dmraid_design.txt /usr/share/man/man8/dmraid.8.gz /var/lock/dmraid
うーんプロプラでは無いから、まあコードを見ろ、そんな難しいことやってないよ、ドイツの科学力は世界一ぃぃぃ、って感じなんだろ、と。えーと、とりあえず、-sしろと。で、Activateするには-ayだと。
# dmraid -s *** Group superset isw_cgejcgagfj --> Subset name : isw_cgejcgagfj_Vol0 size : 1953519616 stride : 128 type : mirror status : ok subsets: 0 devs : 2 spares : 0 # dmraid -ay RAID set "isw_cgejcgagfj_Vol0" was activated # ll /dev/mapper/ total 0 brw-rw---- 1 root disk 253, 1 Nov 29 22:31 VolGroup01-LogVol00 brw-rw---- 1 root disk 253, 0 Nov 29 22:31 VolGroup01-LogVol01 crw------- 1 root root 10, 63 Nov 29 22:31 control brw-rw---- 1 root disk 253, 2 Nov 29 22:32 isw_cgejcgagfj_Vol0
あー、デバイスノードが出来てら。ちゅうことは、fdiskするか、pvcreate/vgcreate/lvcreateするかだわな。とりあえずLVMで。
# fdisk /dev/mapper/isw_cgejcgagfj_Vol0 Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel Building a new DOS disklabel. Changes will remain in memory only, until you decide to write them. After that, of course, the previous content won't be recoverable. The number of cylinders for this disk is set to 121600. There is nothing wrong with that, but this is larger than 1024, and could in certain setups cause problems with: 1) software that runs at boot time (e.g., old versions of LILO) 2) booting and partitioning software from other OSs (e.g., DOS FDISK, OS/2 FDISK) Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite) Command (m for help): n Command action e extended p primary partition (1-4) p Partition number (1-4): 1 First cylinder (1-121600, default 1): Using default value 1 Last cylinder or +size or +sizeM or +sizeK (1-121600, default 121600): Using default value 121600 Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. WARNING: Re-reading the partition table failed with error 22: Invalid argument. The kernel still uses the old table. The new table will be used at the next reboot. Syncing disks. # partprobe /dev/mapper/isw_cgejcgagfj_Vol0 # ll /dev/mapper/isw_cgejcgagfj_Vol0* brw-rw---- 1 root disk 253, 2 Nov 29 22:33 /dev/mapper/isw_cgejcgagfj_Vol0 brw-rw---- 1 root disk 253, 3 Nov 29 22:33 /dev/mapper/isw_cgejcgagfj_Vol0p1 # pvcreate /dev/mapper/isw_cgejcgagfj_Vol0p1 Physical volume "/dev/mapper/isw_cgejcgagfj_Vol0p1" successfully created # vgcreate -s 32M VolGroup00 /dev/mapper/isw_cgejcgagfj_Vol0p1 Volume group "VolGroup00" successfully created # vgdisplay --- Volume group --- VG Name VolGroup01 System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 3 VG Access read/write VG Status resizable MAX LV 0 Cur LV 2 Open LV 2 Max PV 0 Cur PV 1 Act PV 1 VG Size 74.31 GB PE Size 32.00 MB Total PE 2378 Alloc PE / Size 2378 / 74.31 GB Free PE / Size 0 / 0 VG UUID kcEq05-mAM4-CEQ4-z9t6-HYDm-9Vrs-zvvw5v --- Volume group --- VG Name VolGroup00 System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 1 VG Access read/write VG Status resizable MAX LV 0 Cur LV 0 Open LV 0 Max PV 0 Cur PV 1 Act PV 1 VG Size 931.50 GB PE Size 32.00 MB Total PE 29808 Alloc PE / Size 0 / 0 Free PE / Size 29808 / 931.50 GB VG UUID iLmukb-Sq3i-buph-6doM-kkGq-SoW3-jedrfH # lvcreate -l 29808 -n LogVol00 VolGroup00 Logical volume "LogVol00" created # lvdisplay --- Logical volume --- LV Name /dev/VolGroup01/LogVol01 VG Name VolGroup01 LV UUID LI52WN-bwWq-rsme-9YG5-Ko10-n7tJ-0yt4E8 LV Write Access read/write LV Status available # open 1 LV Size 72.31 GB Current LE 2314 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:0 --- Logical volume --- LV Name /dev/VolGroup01/LogVol00 VG Name VolGroup01 LV UUID cTWWR8-Npzf-A2ve-BKJQ-DP9O-zyA3-lSWkXz LV Write Access read/write LV Status available # open 1 LV Size 2.00 GB Current LE 64 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:1 --- Logical volume --- LV Name /dev/VolGroup00/LogVol00 VG Name VolGroup00 LV UUID 0DTn9b-deMD-hv3l-JePf-XOfW-B1hQ-tmMEG0 LV Write Access read/write LV Status available # open 0 LV Size 931.50 GB Current LE 29808 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:4
ま、あとは、mke2fsしてfstabに書けばオッケーだろ。
# mke2fs -j /dev/VolGroup00/LogVol00 mke2fs 1.39 (29-May-2006) Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) 122093568 inodes, 244187136 blocks 12209356 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=4294967296 7452 block groups 32768 blocks per group, 32768 fragments per group 16384 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968, 102400000, 214990848 Writing inode tables: done Creating journal (32768 blocks): done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 29 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override.
念のため、iostatを確認。書けてるみたいだし。
# partprobe /dev/sda /dev/sdb
# iostat
Linux 2.6.18-120.el5 (rhel5.rio.st) 11/29/08
avg-cpu: %user %nice %system %iowait %steal %idle
0.58 0.14 4.24 14.82 0.00 80.21
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 43.42 4.22 43091.95 2486 25411751
sda1 26.76 0.29 27359.45 170 16134144
sdb 46.54 4.24 43312.50 2499 25541815
sdb1 22.81 0.19 21382.59 114 12609528
sdc 25.96 771.38 103.56 454892 61070
sdc1 0.28 21.00 0.02 12386 14
sdc2 25.65 749.90 103.54 442226 61056
dm-0 41.45 746.74 103.54 440362 61056
dm-1 0.21 1.64 0.00 968 0
dm-2 6526.75 1.42 52207.40 837 30787223
dm-3 6526.07 0.35 52207.38 209 30787215
dm-4 6525.94 0.18 52207.36 104 30787200
おっと、忘れてた、mkinitdしておこう。
# mkinitrd -v ./initrd-2.6.18-120.el5.img `uname -r` Creating initramfs Looking for deps of module ehci-hcd Looking for deps of module ohci-hcd Looking for deps of module uhci-hcd Looking for deps of module ext3: jbd Looking for deps of module jbd Looking for driver for device sdc2 Looking for deps of module pci:v00008086d00002822sv00001043sd000082D4bc01sc04i00: scsi_mod libata ahci Looking for deps of module scsi_mod Looking for deps of module sd_mod: scsi_mod Looking for deps of module libata: scsi_mod Looking for deps of module ahci: scsi_mod libata Looking for deps of module usb-storage: scsi_mod Looking for deps of module ide-disk Looking for deps of module dm-mod Looking for deps of module dm-mirror: dm-mod dm-log Looking for deps of module dm-log: dm-mod Looking for deps of module dm-zero: dm-mod Looking for deps of module dm-snapshot: dm-mod Using modules: /lib/modules/2.6.18-120.el5/kernel/drivers/usb/host/ehci-hcd.ko /lib/modules/2.6.18-120.el5/kernel/drivers/usb/host/ohci-hcd.ko /lib/modules/2.6.18-120.el5/kernel/drivers/usb/host/uhci-hcd.ko /lib/modules/2.6.18-120.el5/kernel/fs/jbd/jbd.ko /lib/modules/2.6.18-120.el5/kernel/fs/ext3/ext3.ko /lib/modules/2.6.18-120.el5/kernel/drivers/scsi/scsi_mod.ko /lib/modules/2.6.18-120.el5/kernel/drivers/scsi/sd_mod.ko /lib/modules/2.6.18-120.el5/kernel/drivers/ata/libata.ko /lib/modules/2.6.18-120.el5/kernel/drivers/ata/ahci.ko /lib/modules/2.6.18-120.el5/kernel/drivers/usb/storage/usb-storage.ko /lib/modules/2.6.18-120.el5/kernel/drivers/md/dm-mod.ko /lib/modules/2.6.18-120.el5/kernel/drivers/md/dm-log.ko /lib/modules/2.6.18-120.el5/kernel/drivers/md/dm-mirror.ko /lib/modules/2.6.18-120.el5/kernel/drivers/md/dm-zero.ko /lib/modules/2.6.18-120.el5/kernel/drivers/md/dm-snapshot.ko /sbin/nash -> /tmp/initrd.XL3918/bin/nash /sbin/insmod.static -> /tmp/initrd.XL3918/bin/insmod copy from `/lib/modules/2.6.18-120.el5/kernel/drivers/usb/host/ehci-hcd.ko' [elf64-x86-64] to `/tmp/initrd.XL3918/lib/ehci-hcd.ko' [elf64-x86-64] copy from `/lib/modules/2.6.18-120.el5/kernel/drivers/usb/host/ohci-hcd.ko' [elf64-x86-64] to `/tmp/initrd.XL3918/lib/ohci-hcd.ko' [elf64-x86-64] copy from `/lib/modules/2.6.18-120.el5/kernel/drivers/usb/host/uhci-hcd.ko' [elf64-x86-64] to `/tmp/initrd.XL3918/lib/uhci-hcd.ko' [elf64-x86-64] copy from `/lib/modules/2.6.18-120.el5/kernel/fs/jbd/jbd.ko' [elf64-x86-64] to `/tmp/initrd.XL3918/lib/jbd.ko' [elf64-x86-64] copy from `/lib/modules/2.6.18-120.el5/kernel/fs/ext3/ext3.ko' [elf64-x86-64] to `/tmp/initrd.XL3918/lib/ext3.ko' [elf64-x86-64] copy from `/lib/modules/2.6.18-120.el5/kernel/drivers/scsi/scsi_mod.ko' [elf64-x86-64] to `/tmp/initrd.XL3918/lib/scsi_mod.ko' [elf64-x86-64] copy from `/lib/modules/2.6.18-120.el5/kernel/drivers/scsi/sd_mod.ko' [elf64-x86-64] to `/tmp/initrd.XL3918/lib/sd_mod.ko' [elf64-x86-64] copy from `/lib/modules/2.6.18-120.el5/kernel/drivers/ata/libata.ko' [elf64-x86-64] to `/tmp/initrd.XL3918/lib/libata.ko' [elf64-x86-64] copy from `/lib/modules/2.6.18-120.el5/kernel/drivers/ata/ahci.ko' [elf64-x86-64] to `/tmp/initrd.XL3918/lib/ahci.ko' [elf64-x86-64] copy from `/lib/modules/2.6.18-120.el5/kernel/drivers/usb/storage/usb-storage.ko' [elf64-x86-64] to `/tmp/initrd.XL3918/lib/usb-storage.ko' [elf64-x86-64] copy from `/lib/modules/2.6.18-120.el5/kernel/drivers/md/dm-mod.ko' [elf64-x86-64] to `/tmp/initrd.XL3918/lib/dm-mod.ko' [elf64-x86-64] copy from `/lib/modules/2.6.18-120.el5/kernel/drivers/md/dm-log.ko' [elf64-x86-64] to `/tmp/initrd.XL3918/lib/dm-log.ko' [elf64-x86-64] copy from `/lib/modules/2.6.18-120.el5/kernel/drivers/md/dm-mirror.ko' [elf64-x86-64] to `/tmp/initrd.XL3918/lib/dm-mirror.ko' [elf64-x86-64] copy from `/lib/modules/2.6.18-120.el5/kernel/drivers/md/dm-zero.ko' [elf64-x86-64] to `/tmp/initrd.XL3918/lib/dm-zero.ko' [elf64-x86-64] copy from `/lib/modules/2.6.18-120.el5/kernel/drivers/md/dm-snapshot.ko' [elf64-x86-64] to `/tmp/initrd.XL3918/lib/dm-snapshot.ko' [elf64-x86-64] /sbin/lvm.static -> /tmp/initrd.XL3918/bin/lvm /etc/lvm -> /tmp/initrd.XL3918/etc/lvm `/etc/lvm/lvm.conf' -> `/tmp/initrd.XL3918/etc/lvm/lvm.conf' /sbin/dmraid.static -> /tmp/initrd.XL3918/bin/dmraid /sbin/kpartx.static -> /tmp/initrd.XL3918/bin/kpartx Adding module ehci-hcd Adding module ohci-hcd Adding module uhci-hcd Adding module jbd Adding module ext3 Adding module scsi_mod Adding module sd_mod Adding module libata Adding module ahci Adding module usb-storage Adding module dm-mod Adding module dm-log Adding module dm-mirror Adding module dm-zero Adding module dm-snapshot
ICH10R + dmraidでRAID1を組むの続きを読む
「SATA，SCSI，ファイバチャネル・ドライブの信頼性の相違については読み取れない」の部分がちょっとショックなんですけど。あれー、SATAはコンシューマ向けだってメーカのサイトとかでガイドされてるぞ。
富士通、HDDを2基内蔵してRAID1に対応するノートPCを発売。おおっ、これはきっと需要があるよ。スペースの問題で今まで実現しなかったのかな？
