Comment 64 for bug 569900

Confirmed - after multiple install attempts resulting in /dev/md definition weirdness and a (initramfs) prompt, I finally have 10.04 installed on RAID1 /dev/md partitions. Tried the repartition manually just before installing - no joy. I wiped the disks clean then used the installer and manually set the last partition to be ~1GB smaller than the partitioner was suggesting and _bang_ it worked flawlessly. Here are some details about the setup - you guessed it 2 x 500GB Seagate disks...:

lobo@test:~$ uname -a
Linux test 2.6.32-23-generic #37-Ubuntu SMP Fri Jun 11 07:54:58 UTC 2010 i686 GNU/Linux

/dev/sda:

 Model=ST3500320AS, FwRev=SD15, SerialNo=9QM7HLTS
 Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs RotSpdTol>.5% }
 RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=4
 BuffType=unknown, BuffSize=0kB, MaxMultSect=16, MultSect=16
 CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=976773168
 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
 PIO modes: pio0 pio1 pio2 pio3 pio4
 DMA modes: mdma0 mdma1 mdma2
 UDMA modes: udma0 udma1 udma2 udma3 udma4 udma5 *udma6
 AdvancedPM=no WriteCache=enabled
 Drive conforms to: unknown: ATA/ATAPI-4,5,6,7

/dev/sdb:

 Model=ST3500320AS, FwRev=SD15, SerialNo=9QM63DNQ
 Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs RotSpdTol>.5% }
 RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=4
 BuffType=unknown, BuffSize=0kB, MaxMultSect=16, MultSect=16
 CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=976773168
 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
 PIO modes: pio0 pio1 pio2 pio3 pio4
 DMA modes: mdma0 mdma1 mdma2
 UDMA modes: udma0 udma1 udma2 udma3 udma4 udma5 *udma6
 AdvancedPM=no WriteCache=enabled
 Drive conforms to: unknown: ATA/ATAPI-4,5,6,7

Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000693db

   Device Boot Start End Blocks Id System
/dev/sda1 * 1 132 1060258+ fd Linux raid autodetect
/dev/sda2 133 394 2104515 fd Linux raid autodetect
/dev/sda3 395 60575 483397632 fd Linux raid autodetect

Disk /dev/sdb: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000a1c27

   Device Boot Start End Blocks Id System
/dev/sdb1 * 1 132 1060258+ fd Linux raid autodetect
/dev/sdb2 133 394 2104515 fd Linux raid autodetect
/dev/sdb3 395 60575 483397632 fd Linux raid autodetect

lobo@test:~$ cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md2 : active raid1 sda3[0] sdb3[1]
      483397568 blocks [2/2] [UU]
      [==================>..] resync = 94.6% (457681664/483397568) finish=10.1min speed=41989K/sec

md1 : active raid1 sda2[0] sdb2[1]
      2104448 blocks [2/2] [UU]

md0 : active raid1 sdb1[1] sda1[0]
      1060160 blocks [2/2] [UU]

unused devices: <none>

lobo@test:~$ mount | grep ext4
/dev/md2 on / type ext4 (rw,errors=remount-ro)
/dev/md0 on /boot type ext4 (rw)

lobo@hal:~$ swapon -s
Filename Type Size Used Priority
/dev/md1 partition 2104440 0 -1

Thanks again folks - this was driving me nuts! Hope this helps narrow down the cause.