[Bug 44609] Re: RAID not implemented (use alternate CD instead)

[ceg]

** Tags added: patch

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RAID not implemented (use alternate CD instead)
https://bugs.launchpad.net/bugs/44609
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Status in “mdadm” package in Ubuntu: Confirmed
Status in “ubiquity” package in Ubuntu: Confirmed
Status in “ubiquity” package in Baltix: New

Bug description:
When trying to install from the Flight 7 Live CD (both Ubuntu and Kubuntu) on a system already running Debian Linux with mirrored partitions, the installer does not recognise the meta devices and insists on working with the underlying disk partitions.

The kernel of the Live CD recognises and starts the meta devices just fine.

I would prefer the installer to offer the use of the meta devices, since using the underlying partitions makes it tricky to encapsulate the partitions later in order to get the mirror structure back. Since Ubuntu aims for the corporate environment, it is imperative to support mirrored setups, even for the desktop! Many organisations, especially in the financial sector prefer it that way.

If you decide to fix this bug, please consider to adjust the grub setup as well, to allow for automatic boot from the mirror disk in case the root disk fails.

Attached you will find the disk layout as used on the system (taken from the installed Debian Sid). Additional information is available upon request.

# /sbin/sfdisk -l /dev/hda

Disk /dev/hda: 158816 cylinders, 16 heads, 63 sectors/track
Units = cylinders of 516096 bytes, blocks of 1024 bytes, counting from 0

   Device Boot Start     End   #cyls    #blocks   Id  System
/dev/hda1   *      0+  31001   31002-  15624976+  fd  Linux raid autodetect
/dev/hda2      31002   38751    7750    3906000   fd  Linux raid autodetect
/dev/hda3      38752   79441   40690   20507760   fd  Linux raid autodetect
/dev/hda4      79442  158815   79374   40004496   fd  Linux raid autodetect

# /sbin/sfdisk -l /dev/hdc

Disk /dev/hdc: 158816 cylinders, 16 heads, 63 sectors/track
Units = cylinders of 516096 bytes, blocks of 1024 bytes, counting from 0

   Device Boot Start     End   #cyls    #blocks   Id  System
/dev/hdc1   *      0+  31001   31002-  15624976+  fd  Linux raid autodetect
/dev/hdc2      31002   38751    7750    3906000   fd  Linux raid autodetect
/dev/hdc3      38752   79441   40690   20507760   fd  Linux raid autodetect
/dev/hdc4      79442  158815   79374   40004496   fd  Linux raid autodetect

# cat /proc/mdstat
Personalities : [raid1]
md3 : active raid1 hda4[0] hdc4[1]
      40004416 blocks [2/2] [UU]

md2 : active raid1 hda3[0] hdc3[1]
      19591168 blocks [2/2] [UU]

md1 : active raid1 hda2[0] hdc2[1]
      3903680 blocks [2/2] [UU]

md0 : active raid1 hda1[0] hdc1[1]
      15623104 blocks [2/2] [UU]

unused devices: <none>

# swapon -s
Filename                                Type            Size    Used    Priority
/dev/md1                                partition       3903672 0       -1

# mount
/dev/md0 on / type ext3 (rw,errors=remount-ro)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
usbfs on /proc/bus/usb type usbfs (rw)
tmpfs on /dev/shm type tmpfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/md2 on /export/home type ext3 (rw)
/dev/md3 on /export/scratch type ext3 (rw)
tmpfs on /tmp type tmpfs (rw,mode=1777,size=2G)
tmpfs on /dev type tmpfs (rw,size=10M,mode=0755)
automount(pid6343) on /net type autofs (rw,fd=4,pgrp=6343,minproto=2,maxproto=4)
automount(pid6351) on /home type autofs (rw,fd=4,pgrp=6351,minproto=2,maxproto=4)
nfsd on /proc/fs/nfsd type nfsd (rw)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
/export/home/dominik on /home/dominik type none (rw,bind)