We tried all sorts of things (and when I say "we", jmbach did all the heavy lifting, I pretty much just followed instructions), moving around partitions, coalescing them, and so forth, and were unsuccessful. This method, along with a recompiled mfslive to accommodate bigger drives, was what finally worked. At the very end, it took almost 15 minutes for the last "divorce", and the TiVo had to reboot a couple of times to get everything arranged the way it liked it, but in the end, everything was preserved.
Here is the original post from MFSLive.org:
Guide to consolidating a Series 3 without losing recordings
Postby Thom » Sat Jul 12, 2008 5:06 pm
I have now consolidated 3 different Series 3 machines from a 250GB+750GB configuration to a single 1TB configuration without losing any recordings.
To do this, you will need the MFSLive v1.4 CD.
In my examples below from my Series 3 backups and restores, my system uses the following drive assignments:
hdg = cdrom
sda = destination A drive (1TB)
sdb = source A drive (250GB)
sdc = source B drive (750GB)
Attach all your drives to your computer and boot from the MFSLive CD.
Personally, I like to run a couple of quick tests before I begin the actual copy process, which took about 8 hours on my machine.
My first quick test to make sure I can read the source hard disks:
backup -o /dev/null /dev/sdb /dev/sdc
If successful, my second quick test to make sure I can write the destination hard disk:
backup -qo - /dev/sdb /dev/sdc | restore -zi - /dev/sda
If successful, my actual full copy command (which took about 8 hours):
backup -qTao - /dev/sdb /dev/sdc | restore -zi - /dev/sda
Once the copy is complete, the new drive is still not ready for use. If you were to install it now, you would get a Wrong External Storage Attached message on your Series 3.
Use pdisk on the hard disk to modify the partitions:
pdisk /dev/sda
Press lowercase p to display the partitions on the hard disk. You should see 16 partitions, with Apple_Free being the 16th partition.
Write down the length of the Apple_Free partition (partition 16). This will be referred to as length16.
Now delete partitions 15, 14, and 13:
d 15 d 14 d 13
You can delete them all on one line like above, or you can delete them individually. Start with 15 and work your way to 13.
Now display your partitions with lowercase p again. The Apple_Free partition is now partition 13.
Write down the new length of the Apple_Free partition (partition 13). This will be referred to as length13.
Subtract length16 from length13, and write it down. This will be referred to as length14.
Press uppercase C to create a new partition. Do not use lowercase c as it will not allow you to specify the partition type.
13p will be the starting block. (13p just means use the start block currently assigned to partition 13.)
The length will be the length14 number you calculated.
"Second MFS media region" will be the name of the partition, INCLUDING the quotation marks. If you don't include the quotation marks, only the word Second will be used, and the rest will be discarded.
MFS in uppercase letters will be the type of partition.
Now press p to display your new partition info.
Compare the length of the current Apple_Free partition (should be partition 14) to the length16 number. They should be identical. (Basically, you are checking to make sure that you made the new partition 13 exactly the same length as the old partitions 13, 14 and 15 combined.)
If they are not identical, you made a mistake somewhere. Exit pdisk with a q command, then start pdisk again and try again.
If they are identical, then press lowercase w to write the new partition layout to the hard disk. You will have to answer y to the warning message.
Press q to exit pdisk.
You are done with the hard disk. Install it in your Series 3.
When your Series 3 boots for the first time on the newly consolidated and repartitioned hard disk, you will see a Missing External Storage message. This is expected. Simply follow the on-screen prompts to press the clear button, then to press the thumbs up button three times and to press the enter button.
It will take about 5 minutes to remove all reference to the external drive and reboot.
You will not lose any recordings. They are are still on the newly expanded partition 13 of the A drive.
[EDIT] Automatic expansion by connecting an external drive to the Series 3 will not work after consolidating. It will detect the drive and prompt you as to whether you want to configure the external drive for use by the Series 3, but after it goes through all the preparation steps the external drive will not marry to the internal drive.
[EDIT] You can expand from a single drive Series 3 to a dual drive Series 3 by first running fixdivorce on the single drive, then using mfsadd to add the second drive.
[EDIT] Removed references to "s3backup" and replaced them with "backup" since MFSLive v1.4 works with dual-drive Series 3 machines (v1.3 did not). Added "z" flag to restore command since (I'm told) there is a bug in restore regarding partition boundaries when "z" is not used, but no bug when "z" is used.
- Thom