Topic: creating an array, post-installation

[ltwally]

Scenario:  we  have a functional SME 7.1 server with two mirrored drives.  After the system is already up and kicking, we added a FastTrack controller and 3 more drives.

Question:  How do I use the bundled raid software to put those drives into RAID5?  For the sake of any examples, assume the new drives are hdf, hdg, hdh.

Thanks

[Gaston94]

Hi,
I only know the hard way to do that, and this is not specific to SME, you have to create a partition on your three disk (I suggest sfdisk from the dump of the first one), then create the array, then either create a new LVM structure or directly a FS on that array. The commands should more or less be :

Code: [Select]

# fdisk /dev/hdf
# sfdisk -d /dev/hdf > /tmp/hdf_sfdisk.out
# sfdisk /dev/hdg < /tmp/hdf_sfdisk.out
# sfdisk /dev/hdh < /tmp/hdf_sfdisk.out
#
# mdadm --create /dev/md3 --level 5 --raid-devices=3 /dev/hdf1 /dev/hdg1 /dev/hdh1
#
### follow the raid array status
#
# cat /proc/mdstat
#
### you have to decide here : LVM or not
## no LVM
#
# mke2fs -j /dev/md3
# mount /dev/md3 /mnt/what_ever_youwant
#
## LVM
# pvcreate /dev/md3
# vgcreate vgdata /dev/md3
##the following LV is 10 Gigabyte large - adapt size
# lvcreate --stripes 3  --stripesize 8 --size 10G --name lvdata01 vgdata
# mke2fs -j /dev/vgdata/lvdata01
# mount /dev/vgdata/lvdat01 /mnt/my_lvm_mount_point
#
### if OK add the proper entries in your fstab file
above commands have not been tested, check, control and correct any possible typo
I would recommend the LVM howto reading, many other pages on the web  ...
and before any action a good and verified backup

G.