On 06/05/2016 04:40 AM, Mark Fletcher wrote:
> ... Any clever ploys to deal with [changing UID's and GID's after a
> fresh install]?
For users, I track usernames, UID's, and GID's, and refer to that when
creating accounts.
For services, I restore and chown -R if needed (I don't run many
services, and the Debian project seems to have kept service UID's/GID's
fairly stable over the years).
David
In the end I successfully completed this. I removed the 1TB hard disk which I had already migrated, moved the replacement SSD to where it had been, and plugged in the other SSD which was to replace the 500GB main hard disk. Booted as normal, and the trick was to mount the hard disk (/dev/sda1,sd5,sda6,sda8 and sda9 ) to separate places on the filesystem.
So I created mount points under mnt for newroot, newhome, oldroot, oldusr, oldvar, oldhome, mounted the partitions of the hard disk in those mounts, (in addition to where they were mounted as part of the boot process, eg /, /tmp, /usr etc) and the partitions of the new SSD (which I first had to make) in newroot and newhome. Then it was fairly simple cp -a jobs to copy everything over from there. Doing it that way, I copied what was on the disk surface but didn't inadvertently grab anything that was actually in a virtual file system.
I tried to be clever and use GPT partitions on the first SSD, thus proving I wasn't in fact clever when I tried to install grub and found I needed to have a "BIOS boot partition" (whatever that is) and didn't. So rather than eff around unnecessarily with getting MBR boot to work on a GPT partition I used parted to wipe the label and go back to a "msdos" partition scheme, recreated the partitions and the file systems, and copied everything a second time.
Then, install grub to the SSD using grub-install --boot-directory=/mnt/newroot/boot /dev/sdc and then a grub-mkconfig -o /mnt/newroot/boot/grub/grub.cfg.
Then reboot, and tell the BIOS setup to boot from the SSD first not the hard disk. That fired up grub and I was able to select the SSD-installed Linux. That booted successfully and that's what I'm using to write this.
Because I worked that way I had no file ownership problems, but I did notice messed up permissions on the directories under / that had previously been mount points, eg /usr, /tmp etc. Although /var was OK. For example /usr was world writable which VirtualBox was none too impressed with. Easily fixed, but I don't know why it happened.
Just one thing I wasn't sure about -- what should the permissions of the /media directory be?
Apart from fixing that, what's left to do is to disconnect and remove the 500GB hard disk, move the SSD to the hard disk's SATA port so it is /dev/sda, modify grub.cfg to reflect the move and to remove the hard-disk boot menu items which grub-mkconfig, trying to be helpful, generated.
But I'm basically there apart from my question above about the permissions of /media.
Thanks all for the advice -- was very helpful.
Mark