Apparently, though unproven, at 23:59 on Wednesday 17 November 2010, James did opine thusly:
> Hello, > > I have a ~250 gig sata disk I want to migrate to a 2T > Sata disk. This is simple, but, I have a few caveats. > > old disk: > > Disk /dev/sda: 320.1 GB, 320072933376 bytes > 255 heads, 63 sectors/track, 38913 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: 0x000a1ff7 > > Device Boot Start End Blocks Id System > /dev/sda1 * 1 6405 51448131 7 HPFS/NTFS > /dev/sda2 6406 6431 208845 83 Linux > /dev/sda3 6432 14080 61440592+ 83 Linux > /dev/sda4 14081 38913 199471072+ 5 Extended > /dev/sda5 14081 14861 6273351 82 Linux swap / > Solaris /dev/sda6 14862 26335 92164873+ 83 Linux > /dev/sda7 26336 38913 101032753+ 83 Linux > > > /dev/sda2 /boot reiserfs defaults 1 2 > /dev/sda3 / reiserfs defaults 0 1 > /dev/sda5 none swap sw 0 0 > /dev/sda6 /usr/local reiserfs defaults 0 1 > /dev/sda7 /usr/local/video reiserfs defaults 0 1 > none /proc proc defaults 0 0 > none /dev/shm tmpfs defaults 0 0 > /dev/fd0 /mnt/floppy vfat noauto,user,umask=000 0 0 > #/dev/fd0 /mnt/floppy auto noauto, 0 0 > /dev/cdrom /mnt/cdrom auto noauto,rw,user 0 0 > #/dev/sda1 /mnt/windows ntfs-3g 0 0 > > Disk /dev/sdb: 2000.4 GB, 2000398934016 bytes > 255 heads, 63 sectors/track, 243201 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: 0x5f61c272 > > Device Boot Start End Blocks Id System > > <needs formatting and file systems installed> > > OK, so I format using fdisk <no big deal> No you don't. You will partition it with fdisk and format the filesystems with mkfs* > <new disk will just have /(200G), swap, boot(250M) and one > bit fat /usr/local (1.8T) > > > Ok now I was going to use same reiserfs < no big deal> I dropped my beloved reiserfs systems of many years in favour of ext4. I was seeing ext4 (and the much-hyped btrfs) racing forward into the distance with improvements, useful features and more, while reiser3 languished. The last straw was when I started getting fs errors for no good reason. Let's face it, reiser was Hans. The team he left behind can do maintenance and bug-fixes, but how many features have you seen added in two years? > unless I can use reiser4? good idea? <discuss-caveats> Yuck. It's not in mainline and will never go in mainline. It's not in the tree and will never go in the tree. My understanding is it never actually got finished; and with all those plugins it is just not possible to write a *real* fsck. I would not touch it myself with your bargepole. > > OK now I want the new fstab to use disklabels > <old dog learning new trick here> > > like this simple (few) partition scheme: > /dev/sdb3 200G 52G 42G 55% / > udev 10M 224K 9.8M 3% /dev > /dev/sdb1 250M 47M 189M 20% /boot > /dev/sdb4 1800G 125G 12G 92% /usr/local > > Current <non disklabel fstab> > > /dev/sda1 /boot reiserfs defaults 1 2 > /dev/sda2 none swap sw 0 0 > /dev/sda3 / reiserfs defaults 0 1 > /dev/sda4 /usr/local reiserfs defaults 0 1 > /dev/cdrom /mnt/cdrom auto noauto,ro,user 0 0 > /dev/fd0 /mnt/floppy vfat noauto,user,umask=000 0 0 > shm /dev/shm tmpfs nodev,nosuid,noexec 0 0 > none /proc proc defaults 0 0 > > so what does new fstab using disk labels look like? First you need to mkfs the filesystem with -L <label> fstab looks like this: LABEL=MY_BIG_DISK / reiserfs defaults 0 1 > Last, just dd it over like this? > dd if=/dev/sda of=/dev/sdb bs=32768 Ahem no. That will give you the *identical* filesystems on the new disk as were on the old disk. Which means you have 250G used on a 2T disk with 1.75T unpartitioned, plus the devil's own task of then getting it to be how you actually want > What did I miss? The bit where you use a LiveCD :-) The rub is, that you will be copying files that are subject to being changed, especially /. It's a complete ball-ache trying to deal with this and it involves multiple rsync's and holding of thumbs. A LiveCD lets you do it once in complete confidence. So install the new disk, fdisk it, mkfs it. Then boot off a LiveCD. If you picked a good one, it will mount your disks at /mnt/sda and /mnt/sdb. Now just rsync everything in /mnt/sda* to the right place in /mnt/sdb You do not have exactly the same mount layout on sdb, so some intelligence is needed to do it in the right order, such as in the case of /usr/local and /usr/local/video Reboot. Share. Enjoy. > > Discussion, corrections or caveats are most welcome. -- alan dot mckinnon at gmail dot com
