Replacing hard disk on xenserver / linux software RAID

mark as failed disk :

    mdadm --manage /dev/md0 --fail /dev/sdb1 

remove the disk :

    mdadm --manage /dev/md0 --remove /dev/sdb1

change the physical drive, copy the partition, create the exact same partitioning as on/dev/sda :

    sfdisk -d /dev/sda | sfdisk /dev/sdb

add the new drive

    mdadm --manage /dev/md0 --add /dev/sdb1

done, check the progress :

    cat /etc/mdstat

references:

• https://www.howtoforge.com/replacing_hard_disks_in_a_raid1_array

Xenserver / linux software raid

I want my Storage Repository (SR) run under the software RAID (RAID1). My xenserver version 6.5. XenServer 6.5 do not load soft raid kernel modules on boot. To load soft raid manually run :

modprobe raid1

To load the soft raid module on boot, we can follow this steps : http://discussions.citrix.com/topic/360943-software-raid-mdadm-on-xenserver-65-unexpected-failure/?p=1855912

To build the RAID array :

 
mknod /dev/md1 b 9 1

mdadm --create /dev/md1 --level=1 --raid-devices=2 /dev/sdb1 /dev/sdc1

/dev/sdb1

and

/dev/sdc1

is using linux raid autodetect as the partition type. Use fdisk to create those partition.

To check the RAID building process :

cat /proc/mdstat

reference :

•  https://staff.ie.cuhk.edu.hk/~sfluk/wordpress/wp-content/uploads/2010/06/Software-RAID-on-XenServer.doc
• http://discussions.citrix.com/topic/360943-software-raid-mdadm-on-xenserver-65-unexpected-failure/?p=1855912