Ted Miller wrote: >> I would like to upgrade a CentOS-6.5 home server >> to CentOS-7 on a new partition. >> What is the simplest way to achieve this? > 1. It requires a custom disk layout, but is not particularly hard. > 2. AFAIK, you can share your SWAP partition between the two installations. > 3. Centos 7 uses grub2 as its boot loader. It is significantly different > from "legacy grub" used in Centos 6 and before. > a. It uses a configuration file that is auto-generated, and not > supposed > to be edited. > b. It is capable of finding other installations (including legacy grub > and windows), and creating links to them. > c. 'b' only seems to work IF the other boot partitions are mounted > somewhere in your file tree. What I have done is mount the other > partitions (the /boot partition, if it is on a separate partition, > otherwise /) under /mnt (e.g. /mnt/C6) when you are doing your custom disk > layout. As long as they are mounted somewhere in the file system, grub2 > seems to find them OK, and add them to your boot menu. It is apparently > incapable of looking on unmounted partitions and finding Operating Systems > lurking there. > d. grub2 is (theoretically) capable of booting off of LVM (and I have > done so successfully), BUT that capability is disabled and unsupported in > RHEL/Centos 7. You still have to put /boot on a non-LVM partition. Thanks very much for your response. A couple of comments: 3. Curiously, I see I already have a file /boot/grub2/grub.cfg on my CentOS-6.5 system, though /etc/grub.conf points to /boot/grub/grub.conf . Did I create the grub2 file while experimenting with the system, or is it provided by CentOS-6.5 to simplify upgrading? 3b. When I upgraded another server to CentOS-7 it did not seem to find the old CentOS-6.5, although it found a Windows system OK. However, I was using the old /boot partition for the new system. I'll try mounting the old boot as /mnt/C6 in the custom setup during the new installation, as you suggest. I shall not give a separate partition for the new /boot - hopefully I shall be able to move /boot to a new partition later. I had thought, as an alternative method, of cloning the old system to a new partition, and trying the new CentOSUpgradeTool on this. (I'm running a CentOS-6 KDE system, and note that the documentation for the new tool says it will probably not work with KDE or Gnome - which I would have thought would rule out 95% of systems - but it wouldn't matter too much if I still had the old system.) -- Timothy Murphy e-mail: gayleard /at/ eircom.net School of Mathematics, Trinity College, Dublin 2, Ireland