2010.12.03
Šarūnas Burdulis
Department of Mathematics
Dartmouth College
Iomega StorCenter Pro ix4-100 NAS server was originally purchased with four 1TB disks providing 1.8TB of NAS in RAID-10 setup. 1.5 years later four 2TB disks were purchased with an intention to replace the original ones and to double the NAS capacity. Simply replacing the disks didn't work (StorCenter does not boot). It appears that part of its operating system resides on the same NAS disks. Attaching one of the original disks via SATA-USB adapter to a host PC revealed two ‘linux_raid’ type partitions. First partition (1GB in size) was mountable as ext2 and appeared to contain several compressed ROMFS images. This first partition must have been mirrored across the rest of the disks. The second partition could not be mounted directly, which was expected (stripes of RAID-10).
It looked like recreating the original first partition and its data on new, larger disks might result in working StorCenter NAS with upgraded capacity.
StorCenter software version at the time of upgrade: 2.0.15.43099.
Connect the first original disk to a Linux host using SATA-USB adapter.
'fdisk -l' showed a new device with two partitions,
which in our case were /dev/sdd{1,2}.
Backup MBR and partition table:
dd if=/dev/sdd of=d1.mbr count=1 bs=512
Backup the first (“system”) partition:
dd if=/dev/sdd1 of=d1.part1 bs=512
Repeat for the remaining 3 original disks.
Connect a new disk via SATA-USB. Write partition table
from the first original disk to the first new disk:
dd if=d1.mbr of=/dev/sdd; sync; partprobe
Restore “system” partition contents to a new disk:
dd if=d1.part1 of=/dev/sdd1 bs=512; sync
cfdisk to remove the second partition, which is too small for the bigger new disks.
Create a new one using the full capacity.
Repeat for the remaining 3 new disks.
Put new disks into StorCenter, which boots normally. Web management interface is available. Most settings are preserved, except for the network shares, which of course no longer exist. RAID-10 initialization starts automatically for the second partition (it's the only one “visible” in the management interface). RAID initialization completes in several minutes, after which NAS shares can be configured and accessed from the network. At the same time StorCenter starts ‘“Data Protection” reconstruction’, which for the new 3.6TB RAID-10 volume takes roughly 30 hours to complete (NAS clients disconnected in order to speed up the process).