EFI and GPT Muddle with RHEL
- A server I recently installed (not Sun, not HP, not Dell, but someone else) was found to have: disks, on which sat, on arrival, GPT — GUID partition tables; but with old-fashioned, non-EFI BIOS.
- GPT is part of the EFI standard and supported by only some old-fashioned BIOSs.
- RedHat have made the decision that (in RHEL at least) they do not support GPT without EFI.
- Fdisk does not support GPT.
- The versions of Parted that come with both RHEL v5.5 and Fedora v13 have some "issues" with GPT — see below.
- PXE-booting RHEL v5.5 (well, SL v5.5 actually), we get to the disk-formatting stage: your boot partition is on a disk using the GPT partitioning scheme, but this machine cannot boot using GPT. Apparently, Anaconda includes some sanity-checks which take the "safe" option of assuming only EFI can boot GPT. Hmmm.
- Ctrl-Alt-F2 out of Anaconda to shell and flatten the GPT stuff:
- Fdisk does not do GPT, though it does report its existence.
- Parted does do GPT, but attempts to use RHEL and later Fedora's parted manifested stack-dumps and all manner of problems.
- dd if=/dev/urandom of=/dev/sda eventually sorted things out, at the second attempt — it seems that one has to run dd long enough to flatten both copies of the GPT tables, otherwise Parted gets very upset, Anaconda attempts to rebuilt what it thinks are accidently-messed up GPT tables. . .
- Finally, SL v5.5 installs fine.