identificar bien los discos
Usar el comando
# hdparm -I /dev/sdb | less
/dev/sdb:
ATA device, with non-removable media
Model Number: Hitachi HDS721010CLA332
Serial Number: JP2930HQ0WGG0H
Firmware Revision: JP4OA39C
Transport: Serial, ATA8-AST, SATA 1.0a, SATA II Extensions, SATA Rev 2.5; Revision: ATA8-AST T13 Project D1697 Revision 0b
.....
Agregar un nuevo array con 2 nuevos discos
- Particionar los 2 discos con fdisk con el tipo de partición "linux raid autodetect" (FD)
- Crear el nuevo array con las nuevas particiones, fijarse bien el device raid mdX y las particiones sdXX.
# mdadm --create --verbose /dev/md3 --level=1 --raid-devices=2 /dev/sdc1 /dev/sdd1
- Formatear el nuevo array en ext3
# mkfs.ext3 /dev/md3
- Agregar la configuración del nuevo array al /etc/mdadm/mdam.conf
# mdadm --detail --scan | grep md3 >> /etc/mdadm/mdadm.conf
- Es una buena idea de hacer un reboot del servidor para ver si el array vuelve bien con un reboot.
- Agregar el punto de montaje en el archivo /etc/fstab con el UUID correcto.
# blkid | grep md3 /dev/md3: UUID="fcecd711-924d-4193-8533-3f7b3ae8bcc7" TYPE="ext3"
Un ejemplo del archivo /etc/fstabUUID=fcecd711-924d-4193-8533-3f7b3ae8bcc7 /home ext3 defaults 0 2
- Es una buena idea de hacer un reboot del servidor para ver si el punto de montaje vuelve bien después de un reboot.
Agregar Nuevo Disco
- Copiar tabla de particiones un disco al nuevo
# sfdisk -d /dev/sda | sfdisk --no-reread /dev/sdb --force
- Agregar al raid1 el nuevo disco (sdb)
# mdadm --add /dev/md0 /dev/sdb2 # mdadm --add /dev/md1 /dev/sdb5 # mdadm --add /dev/md2 /dev/sdb6
- Quitar particion al raid1
# mdadm --fail /dev/md0 /dev/sdb2 # mdadm -r /dev/md0 /dev/sdb2
Quitar RAID
- Quitar un disco fallido de una RAID:
# mdadm --remove /dev/md0 /dev/sdb1
- Limpiar cualquier información previa de un disco RAID (Ej. al reutilizar un disco de otra raid antigua)
# mdadm --zero-superblock /dev/sdb1
- más info:
http://www.ducea.com/2009/03/08/mdadm-cheat-sheet/
http://svn.debian.org/wsvn/pkg-mdadm/mdadm/trunk/debian/README.recipes?op=file&rev=0&sc=0
https://wiki.koumbit.net/RaidRecovery
http://danielpecos.com/wiki/Howto:_RAID_en_Linux
- Si los discos se salen del array
Puede ser que los cause el smartd con el kernel. http://kerneltrap.org/mailarchive/linux-scsi/2009/9/14/6409773
- Grub al disco (para que varios puedan bootear sin que se rompan)
# grub Probing devices to guess BIOS drives. This may take a long time. [...] grub> device (hd0) /dev/sdb device (hd0) /dev/sdb grub> root (hd0,0) root (hd0,0) Filesystem type is ext2fs, partition type 0xfd grub> setup (hd0) setup (hd0) Checking if "/boot/grub/stage1" exists... yes Checking if "/boot/grub/stage2" exists... yes Checking if "/boot/grub/e2fs_stage1_5" exists... yes Running "embed /boot/grub/e2fs_stage1_5 (hd0)"... 16 sectors are embedded. succeeded Running "install /boot/grub/stage1 (hd0) (hd0)1+16 p (hd0,1)/boot/grub/stage2 /boot/grub/menu.lst"... succeeded Done.
- Cambiar de posición el disco ( slot number )
mdadm --detail /dev/md1 Number Major Minor RaidDevice State 0 0 0 0 removed 1 8 17 1 active sync /dev/sdb1 What I wanted to do is to move the device /dev/sdb1 to slot 0 from slot 1. And I found I could do that by running mdadm in grow mode with the degraded Raid 1 array: mdadm --grow --force -n 1 /dev/md1 mdadm --detail /dev/md1 Number Major Minor RaidDevice State 0 8 22 0 active sync /dev/sdb1 mdadm --grow -n 2 /dev/md1 mdadm --detail /dev/md1 Number Major Minor RaidDevice State 0 8 17 0 active sync /dev/sdb1 1 0 0 1 removed Then add a new device into md1 mdadm /dev/md1 -a /dev/sda1 mdadm: hot added /dev/sda1
http://piiis.blogspot.com/2009/03/change-slot-number-of-raid-1-device-by.html
Degraded Boot
Si se rompe un disco "primario" del array, y el "secundario" no tiene instalado GRUB2, seguir las instrucciones de https://help.ubuntu.com/community/Grub2#ChRoot . Ojo: El LiveCD tiene que ser del mismo release y arquitectura.
ChRoot
This method of installation uses the chroot command to gain access to the broken system's files. Once the chroot command is issued, the LiveCD treats the broken system's / as its own. Commands run in a chroot environment will affect the broken systems filesystems and not those of the LiveCD.
1. Boot to the LiveCD Desktop. The CD should be the same release and architecture (32/64 bit).
2.
Open a terminal - Applications, Accessories, Terminal.
3.
Only If the normal system partition(s) are on a software RAID (otherwise skip this step): make sure the mdadm tools are installed in the Live CD environment (e.g. by executing sudo apt-get install mdadm). Then assemble the arrays:
sudo mdadm --assemble --scan
4. Determine your normal system partition (the switch is a lowercase "L"):
sudo fdisk -l
If you aren't sure, run df -Th. Look for the correct disk size and ext3 or ext4 format.
5. Mount your normal system partition:
* Substitute the correct partition: sda1, sdb5, etc.
sudo mount /dev/sdXX /mnt
*
Example 1: sudo mount /dev/sda1 /mnt
*
Example 2: sudo mount /dev/md1 /mnt
6.
Only if you have a separate boot partition (where sdYY is the /boot partition designation):
sudo mount /dev/sdYY /mnt/boot
*
Example 1: sudo mount /dev/sdb6 /mnt/boot
*
Example 2: sudo mount /dev/md0 /mnt/boot
7. Mount the critical virtual filesystems. Run the following as a single command:
for i in /dev /dev/pts /proc /sys; do sudo mount -B $i /mnt$i; done
8. Chroot into your normal system device:
sudo chroot /mnt
9.
Only if (some) of the system partitions are on a software RAID (otherwise skip this step): make sure the output of mdadm --examine --scan agrees with the array definitions in /etc/mdadm/mdadm.conf.
10.
If the file /boot/grub/grub.cfg does not exist or it is not correct, (re)create it using
update-grub
11.
Reinstall GRUB 2 (substitute the correct device with sda, sdb, etc. Do not specify a partition number):
grub-install /dev/sdX
If the system partitions are on a software RAID install GRUB 2 on all disks in the RAID. Example (software RAID using /dev/sda and /dev/sdb):
grub-install /dev/sda
grub-install /dev/sdb
12.
Verify the install (use the correct device, for example sda. Do not specify a partition):
grub-install --recheck /dev/sdX
For a system on a software RAID, repeat this for all devices in the RAID.
13.
Exit chroot: CTRL-D on keyboard
14. Unmount virtual filesystems. Run the following as a single command:
for i in /sys /proc /dev/pts /dev; do sudo umount /mnt$i; done
15. If you mounted a separate /boot partition:
*
sudo umount /mnt/boot
16. Unmount last device:
sudo umount /mnt
17. Reboot.
sudo reboot
Last modified
13 years ago
Last modified on 04/10/12 13:39:04
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