Bug 1027833
| Summary: | grub2-mkconfig does not honor GRUB_DISABLE_LINUX_UUID correctly | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Jiri Benc <jbenc> |
| Component: | grub2 | Assignee: | Peter Jones <pjones> |
| Status: | CLOSED ERRATA | QA Contact: | Release Test Team <release-test-team-automation> |
| Severity: | unspecified | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 7.0 | CC: | jbenc, mbanas, pholica |
| Target Milestone: | rc | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | grub2-2.02-0.11.el7 | Doc Type: | Bug Fix |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2015-03-05 11:12:29 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
According to info pages:
'GRUB_DISABLE_LINUX_UUID'
Normally, 'grub2-mkconfig' will generate menu entries that use
universally-unique identifiers (UUIDs) to identify the root
filesystem to the Linux kernel, using a 'root=UUID=...' kernel
parameter. This is usually more reliable, but in some cases it may
not be appropriate. To disable the use of UUIDs, set this option
to 'true'.
If I get this right, you want to disable lookup by UUID of partition containing kernel and ramdisk? Looking to grub documentation, this can be done by looking for file on partition or by filesystem label.
I'm asking because there is no information how result should look like.
(In reply to Pavel Holica from comment #2) > If I get this right, you want to disable lookup by UUID of partition > containing kernel and ramdisk? Looking to grub documentation, this can be > done by looking for file on partition or by filesystem label. Yes, and the GRUB_DISABLE_LINUX_UUID is exactly for that but it doesn't work. > I'm asking because there is no information how result should look like. I'd expect /dev/sda1 or so. Or (hd0,0) or whatever the correct syntax is at that place. (In reply to Pavel Holica from comment #5) > No, If you read documentation, it's for linux root, which means setting > kernel parameter root=... > The search is for grub to know where /boot is located, so it can load kernel > and ramdisk. Okay, I stand corrected. Nevertheless, the GRUB_DISABLE_LINUX_UUID option is kinda pointless without this. > Grub at this stage doesn't know anything about linux devices, so it needs > some way of looking for such device (using UUID, label or something like > this). > > Anyway, I'm adding qa_ack+, but I don't agree with using this option, I'd > vote for GRUB_DISABLE_UUID or something like this. Works for me. Any solution that allows not relying on UUIDs is okay. When GRUB_DISABLE_UUID is used in /etc/default/grub (and grub config re-generated), there are no UUIDs when specifying device holding kernel and ramdisk. Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHBA-2015-0492.html |
Although /etc/grub.d/10_linux correctly handles GRUB_DISABLE_LINUX_UUID=true specified in /etc/default/grub and generates correct "linux" entry, it's not checked in prepare_grub_to_access_device, generating if [ x$feature_platform_search_hint = xy ]; then search --no-floppy --fs-uuid --set=root xxxxxxxx-... else search --no-floppy --fs-uuid --set=root xxxxxxxx-... fi in grub.cfg (my UUID replaced by xxxxxxxx-...). This makes grub2 output error message, waiting for a key to be pressed (thus fatal on remote machines) if the UUID is changing (which is the reason to use GRUB_DISABLE_LINUX_UUID in the first place).