RE: search by PARTUUID
Hi Matt > I wrote a patch a while ago for this. I ended up creating an add-on command, > that uses the partition UUID/GUID, to search (--pt-uuid) and > an accompanying module search.pt_uuid. These two commands mirror the search > --fs-uuid and search.fs_uuid where given a uuid it will > return the device. When given a disk/partition UUID/GUID that corresponds to > a disk that is either a biosdisk or efidisk, or a partition with > a partmap name of either "msdos" or "gpt" on one of the previous disks it > will return that device. I checked it against the master and it > applied cleanly. I can post it in a day. That's exactly what I'm looking for. I appreciate if you can post the patches. Did you try to upstream them? Many Thanks Urs > -Original Message- > From: mat...@protonmail.com [mailto:mat...@protonmail.com] > Sent: Freitag, 13. April 2018 07:33 > To: help-grub@gnu.org; Ritzmann Urs > Subject: Re: search by PARTUUID > > I wrote a patch a while ago for this. I ended up creating an add-on command, > that uses the partition UUID/GUID, to search (--pt-uuid) and > an accompanying module search.pt_uuid. These two commands mirror the search > --fs-uuid and search.fs_uuid where given a uuid it will > return the device. When given a disk/partition UUID/GUID that corresponds to > a disk that is either a biosdisk or efidisk, or a partition with > a partmap name of either "msdos" or "gpt" on one of the previous disks it > will return that device. I checked it against the master and it > applied cleanly. I can post it in a day. > > Best regards, > > Matt > ___ Help-grub mailing list Help-grub@gnu.org https://lists.gnu.org/mailman/listinfo/help-grub
Re: search by PARTUUID
I wrote a patch a while ago for this. I ended up creating an add-on command, that uses the partition UUID/GUID, to search (--pt-uuid) and an accompanying module search.pt_uuid. These two commands mirror the search --fs-uuid and search.fs_uuid where given a uuid it will return the device. When given a disk/partition UUID/GUID that corresponds to a disk that is either a biosdisk or efidisk, or a partition with a partmap name of either "msdos" or "gpt" on one of the previous disks it will return that device. I checked it against the master and it applied cleanly. I can post it in a day. Best regards, Matt Original Message On Apr 12, 2018, 17:21, Pascal Hambourg wrote: Le 12/04/2018 à 09:17, Urs Ritzmann a écrit : > >> From: Pascal Hambourg [mailto:pas...@plouf.fr.eu.org] >> >> Le 11/04/2018 à 10:00, Urs Ritzmann a écrit : >>> >>> Currently, the filesystem UUID is used in the search. It works, but the fs >>> UUID has to be updated after an image update which is a bit >> ugly. A constant PARTUUID pointing to current image would be more clean. >> >> Can't the same UUID be used when creating a new image ? > > The same image can be installed to different partitions (e.g. in a fail-safe > dual-copy approach, the currently active image always updates another, > inactive image, then toggles the boot to the new one). > > In case the same image is installed twice (to different partitions), I would > end up with both images having the same UUID. And that would be a bad thing, because UUIDs are supposed to be unique. You wrote that rewriting the filesystem UUID was a bit ugly, but IMO not doing it and having duplicate UUIDs is much more ugly. Looking at the grub-devel mailing list archives, I found out that some patches have been submitted to add support for partition UUIDs in GRUB. But I don't know their status nor whether that is exactly the kind of support that you are looking for. IIUC, the submitter seemed more interested in using PARTUUID in the Linux kernel root parameter than in search commands. ___ Help-grub mailing list Help-grub@gnu.org https://lists.gnu.org/mailman/listinfo/help-grub ___ Help-grub mailing list Help-grub@gnu.org https://lists.gnu.org/mailman/listinfo/help-grub
Re: search by PARTUUID
Le 12/04/2018 à 09:17, Urs Ritzmann a écrit : From: Pascal Hambourg [mailto:pas...@plouf.fr.eu.org] Le 11/04/2018 à 10:00, Urs Ritzmann a écrit : Currently, the filesystem UUID is used in the search. It works, but the fs UUID has to be updated after an image update which is a bit ugly. A constant PARTUUID pointing to current image would be more clean. Can't the same UUID be used when creating a new image ? The same image can be installed to different partitions (e.g. in a fail-safe dual-copy approach, the currently active image always updates another, inactive image, then toggles the boot to the new one). In case the same image is installed twice (to different partitions), I would end up with both images having the same UUID. And that would be a bad thing, because UUIDs are supposed to be unique. You wrote that rewriting the filesystem UUID was a bit ugly, but IMO not doing it and having duplicate UUIDs is much more ugly. Looking at the grub-devel mailing list archives, I found out that some patches have been submitted to add support for partition UUIDs in GRUB. But I don't know their status nor whether that is exactly the kind of support that you are looking for. IIUC, the submitter seemed more interested in using PARTUUID in the Linux kernel root parameter than in search commands. ___ Help-grub mailing list Help-grub@gnu.org https://lists.gnu.org/mailman/listinfo/help-grub
RE: search by PARTUUID
Hi > From: Pascal Hambourg [mailto:pas...@plouf.fr.eu.org] > > Le 11/04/2018 à 10:00, Urs Ritzmann a écrit : > > > > Currently, the filesystem UUID is used in the search. It works, but the fs > > UUID has to be updated after an image update which is a bit > ugly. A constant PARTUUID pointing to current image would be more clean. > > Can't the same UUID be used when creating a new image ? The same image can be installed to different partitions (e.g. in a fail-safe dual-copy approach, the currently active image always updates another, inactive image, then toggles the boot to the new one). In case the same image is installed twice (to different partitions), I would end up with both images having the same UUID. -- Many Thanks Urs ___ Help-grub mailing list Help-grub@gnu.org https://lists.gnu.org/mailman/listinfo/help-grub
RE: search by PARTUUID
> What would be the use case ? Ok, let me elaborate my motivation. It's an embedded setup with the following characteristics: - The kernel is part of the root filesystem and loaded from there. - There are multiple (redundant) root filesystems (each including its own kernel). - Updates are always performed on a full image, meaning that one of the root filesystems is completely re-written during an update. - PARTUUID would point to the most recently updated Image (partition containing rootfs/kernel). The thing is that when rewriting the filesystem during an update, the filesystem UUID changes, where in contrast, the partition UUID stays constant. So using the PARTUUID would be a better solution. > IOW, why can't you use another search option ? Currently, the filesystem UUID is used in the search. It works, but the fs UUID has to be updated after an image update which is a bit ugly. A constant PARTUUID pointing to current image would be more clean. -- Many Thanks Urs ___ Help-grub mailing list Help-grub@gnu.org https://lists.gnu.org/mailman/listinfo/help-grub
Re: search by PARTUUID
Le 10/04/2018 à 16:25, Urs Ritzmann a écrit : Is there any way to search for the device name by GPT partition UUID or by partition label from the GRUB command-line? I'd like to search and boot a kernel by GPT partition UUID or partition label. What would be the use case ? IOW, why can't you use another search option ? ___ Help-grub mailing list Help-grub@gnu.org https://lists.gnu.org/mailman/listinfo/help-grub
