08
février 2011
INSIA - Technologies UNIX : TP N°3
Rédigé par Matthieu CERDA Aucun commentaire Mis à jour le 08/02/2011
Commençons par créer deux HDD pour la VM, soit via VirtualBox/QEMU/YMMV, soit via :
[code lang="shell"]
VBoxManage clonehd
VBoxManage clonehd
[/code]
On lance la VM et on obtient :
[code lang="shell"]
% dmesg
[ 7.286698] sd 0:0:0:0: [sda] 16777216 512-byte hardware sectors (8590 MB)
[ 7.287451] sd 0:0:0:0: [sda] Write Protect is off
[ 7.287460] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
[ 7.287757] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 7.289939] sd 0:0:0:0: [sda] 16777216 512-byte hardware sectors (8590 MB)
[ 7.290105] sd 0:0:0:0: [sda] Write Protect is off
[ 7.290114] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
[ 7.290413] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 7.290447] sda: sda1 sda2
[ 7.319499] sd 0:0:0:0: [sda] Attached SCSI disk
[ 7.320055] sd 1:0:0:0: [sdb] 16777216 512-byte hardware sectors (8590 MB)
[ 7.320055] sd 1:0:0:0: [sdb] Write Protect is off
[ 7.320055] sd 1:0:0:0: [sdb] Mode Sense: 00 3a 00 00
[ 7.320194] sd 1:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 7.320644] sd 1:0:0:0: [sdb] 16777216 512-byte hardware sectors (8590 MB)
[ 7.320858] sd 1:0:0:0: [sdb] Write Protect is off
[ 7.320870] sd 1:0:0:0: [sdb] Mode Sense: 00 3a 00 00
[ 7.321269] sd 1:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 7.321287] sdb: sdb1 sdb2
[ 7.325881] sd 1:0:0:0: [sdb] Attached SCSI disk
% sudo sfdisk -l /dev/sda
[sudo] password for kegeruneku:
Disk /dev/sda: 1044 cylinders, 255 heads, 63 sectors/track
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0
Device Boot Start End #cyls #blocks Id System
/dev/sda1 0+ 248 249- 2000061 83 Linux
/dev/sda2 249 372 124 996030 82 Linux swap / Solaris
/dev/sda3 0 - 0 0 0 Empty
/dev/sda4 0 - 0 0 0 Empty
[/code]
On wipe le second disque si c'est une copie du premier :
[code lang="shell"]
root@VM # dd if=/dev/zero of=/dev/sd{b,c} bs=1M count=512
512+0 enregistrements lus
512+0 enregistrements écrits
536870912 bytes (537 MB) copied, 7,62033 s, 70,5 MB/s
root@VM # sync
root@VM # # Et on crée des partitions identiques sur les deux via cfdisk, puis :
root@VM # sfdisk -d /dev/sdb | sfdisk /dev/sdc # Hop on copie la table de partitions
root@VM # aptitude install mdadm
[/code]
Petit topo sur le RAID : Wikipédia
[code lang="shell"]
% # Et c'est parti !
% sudo mdadm -C /dev/md0 --level=raid1 --raid-devices=2 /dev/sdb /dev/sdc
# On peut utiliser un disque ou une partition, au choix. Linux MD Powah !
mdadm: array /dev/md0 started.
% sudo mke2fs -j /dev/md0
% sudo mkdir /mnt/raid && sudo mount /dev/md0 /mnt/raid
% # Et voila. On a un RAID1 *magie*
% # On peut essayer de déclarer un disque cassé :
% sudo mdadm --set-faulty /dev/md0 /dev/sdc
mdadm: set /dev/sdc faulty in /dev/md0
Mail version 8.1.2 01/15/2001. Type ? for help.
"/var/mail/kegeruneku": 1 message 1 new
>N 1 root@trollface.et Tue Feb 08 12:43 31/1126 Fail event on /dev/md0:trollface
& 1
Message 1:
From root@trollface.etudiant.insia.org Tue Feb 08 12:43:42 2011
Envelope-to: root@trollface.etudiant.insia.org
Delivery-date: Tue, 08 Feb 2011 12:43:42 +0100
From: mdadm monitoring
To: root@trollface.etudiant.insia.org
Subject: Fail event on /dev/md0:trollface
Date: Tue, 08 Feb 2011 12:43:42 +0100
This is an automatically generated mail message from mdadm
running on trollface
A Fail event had been detected on md device /dev/md0.
It could be related to component device /dev/sdc.
Faithfully yours, etc.
P.S. The /proc/mdstat file currently contains the following:
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid1 sdc[2](F) sdb[0]
8388544 blocks [2/1] [U_]
unused devices:
% # Whaaaaaa ... moderne et poli j'aime
% sudo mdadm --detail /dev/md0
/dev/md0:
Version : 00.90
Creation Time : Tue Feb 8 12:25:41 2011
Raid Level : raid1
Array Size : 8388544 (8.00 GiB 8.59 GB)
Used Dev Size : 8388544 (8.00 GiB 8.59 GB)
Raid Devices : 2
Total Devices : 2
Preferred Minor : 0
Persistence : Superblock is persistent
Update Time : Tue Feb 8 12:43:42 2011
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 1
Spare Devices : 0
UUID : 0d09dc47:55563fbe:86ade1c2:8d372aa1 (local to host trollface)
Events : 0.8
Number Major Minor RaidDevice State
0 8 16 0 active sync /dev/sdb
1 0 0 1 removed
2 8 32 - faulty spare /dev/sdc
% # Saytoucassé ? zut...
% sudo mdadm --remove /dev/md0 /dev/sdc
mdadm: hot removed /dev/sdc
% sudo dd if=/dev/zero of=/dev/sdc bs=1M count=128
% # On remet le disque a blanc vite fait
% sudo mdadm --adde /dev/md0 /dev/sdc
mdadm: re-added /dev/sdc
% # Et la c'est le pied !
% cat /proc/mdstat
0.00 0.00 - 3% 0%]
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid1 sdc[2] sdb[0]
8388544 blocks [2/1] [U_]
[=>...................] recovery = 5.1% (430016/8388544) finish=3.3min speed=39092K/sec
unused devices:
% sudo mdadm --detail /dev/md0
/dev/md0:
Version : 00.90
Creation Time : Tue Feb 8 12:25:41 2011
Raid Level : raid1
Array Size : 8388544 (8.00 GiB 8.59 GB)
Used Dev Size : 8388544 (8.00 GiB 8.59 GB)
Raid Devices : 2
Total Devices : 2
Preferred Minor : 0
Persistence : Superblock is persistent
Update Time : Tue Feb 8 12:51:21 2011
State : clean, degraded, recovering
Active Devices : 1
Working Devices : 2
Failed Devices : 0
Spare Devices : 1
Rebuild Status : 8% complete
UUID : 0d09dc47:55563fbe:86ade1c2:8d372aa1 (local to host trollface)
Events : 0.14
Number Major Minor RaidDevice State
0 8 16 0 active sync /dev/sdb
2 8 32 1 spare rebuilding /dev/sdc
% # Ooooh ... merci uncle Tom, merci !
[/code]
Bon allez la ça rigole plus, on enfile ses plus beaux poils et on se lance dans LVM la hop hop allez on se grouille, motivé les enfants !!!
Allez trêve de parlottes, fais péter le shell tonton en avant :
[code lang="shell"]
% sudo aptitude install lvm2
<I CAN HAZ LVM PLZ ? KTHXBYE>
[/code]
La suite au prochain épisode !
