On Oct 21, 2008, at 5:02 PM, [EMAIL PROTECTED] wrote: >>> Anyone installed ubuntu to be >>> dual boot with centos? What do I look out for? >> >> If you wanted to use a shared /boot between the two, it'd be a bit >> messy... For one, Ubuntu uses menu.lst for its grub config, CentOS >> uses >> grub.conf, with a menu.lst symlink to it, so depending on which >> distros >> version of grub is actually installed into the boot sector... >> >> What I'd do is have separate /boot partitions for each. Install >> Ubuntu >> with /dev/sda1 as /boot, with grub installed into the MBR. Then >> install >> CentOS with /dev/sda2 as its boot, and install grub into the >> beginning >> of the partition, instead of the MBR. Now configure Ubuntu's grub to >> chainload CentOS' grub on /dev/sda2. Then both can happily update >> their >> boot menu options without stomping on one another. >> > > I already have CentOS installed on my machine.
Ah. That complicates things, unless you happened to leave a bunch of free space on the disk... Or are using lvm and feel comfortable shrinking partitions... > I don't really understand > your explanation of what to do. I think it is a reflection of my > knowledge in this area rather than your explanation. If there were nothing already installed, 6 partitions is what I'd do: /dev/sda1 -- ~100MB /boot for Ubuntu /dev/sda2 -- ~100MB /boot for CentOS /dev/sda3 -- some appropriate amount of swap (can be used by both) /dev/sda5 -- / for Ubuntu /dev/sda6 -- / for CentOS /dev/sda7 -- /data or some such thing, for data you want shared between the two I'd make /data as /home potentially, but I don't know how well using a shared /home directory would be, given that the versions of gnome differ by about a year and a half between current Ubuntu and CentOS... So you install Ubuntu first, saving space for CentOS. Ubuntu installs grub into the master boot record of the drive. Next, you install CentOS. When it asks about bootloader, choose to customize, and install it into /dev/sda2 instead of the master boot record. Everything else should be the same as usual. Now, when you reboot, only Ubuntu will be available. Boot it, and add a chainloader entry to /boot/grub/menu.lst that points to /dev/sda2 (I forget the exact syntax for this). Now reboot again. If you choose the chainloader option, it'll spin up the CentOS copy of grub, and you can choose which CentOS kernel to boot. (I believe you could also add a chainloader option in the CentOS grub to hop back to the Ubuntu grub). You could also of course flip-flop the two, which is what it sounds like you might be looking at doing, since CentOS is already installed. > What do I need to change in CentOS first? First and foremost, you need disk space free. > How do I alter the Ubuntu install, so I don't hose the CentOS install? Definitely need to do custom partitioning, making sure not to blow away the CentOS partitions. > Why are these linices hostile to each other? Philosophical > question, I > sort of understand your explanation. Many linux distros are > tolerant to a > dual boot with windows, but not as it seems, to other linux distros? Like Bill said, some distros have slightly different flavors of bootloaders, and yeah, they typically only anticipate coexisting with a Windows install. I *think* I vaguely recall seeing openSUSE preserve bootloader configs from another Linux install once. But yeah, even Red Hat Enterprise Linux and Fedora don't cooperate together, the second one installed moves the first's grub.conf out of the way if you use a shared /boot, so you have to actually munge the old grub.conf.rpmsave onto the end of the new grub.conf. Then things pretty much Just Work. Should actually be doable with an Ubuntu/CentOS mix as well, with liberal use of symlinks, I think... -- Jarod Wilson [EMAIL PROTECTED] _______________________________________________ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/