[opensuse] Quick question re: new versions of SLES/openSuse and booting
Just out of curiosity - In the past it was usually recommended to have a separate /boot partition, and for that partition to be the first one of the disk. However, I've noticed that in openSuSE 13.2 and SLES 12 that the default now is to not create this partition, and to instead install the bootcode into "/" directly, with /boot being a subfolder of the root partition. Has something changed with regards to "best practices," or is there another reason that this is the default now? Just wanting to make sure that I build my systems correctly with the new versions :) -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On Tue, 2014-11-11 at 15:48 -0600, Christopher Myers wrote:
Just out of curiosity -
In the past it was usually recommended to have a separate /boot partition, and for that partition to be the first one of the disk. However, I've noticed that in openSuSE 13.2 and SLES 12 that the default now is to not create this partition, and to instead install the bootcode into "/" directly, with /boot being a subfolder of the root partition.
Has something changed with regards to "best practices," or is there another reason that this is the default now?
Just wanting to make sure that I build my systems correctly with the new versions :)
I presume (from the top of my head) it has something to do with (u)efi. Some installation create a separate vfat (brrr) partition and mount it upon /boot/efi. Perhaps it is considered too dangerous to leave kernels and initrd visible to windows, hence they moved it elsewhere... hw -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
Hans Witvliet 11/11/14 4:40 PM >>> On Tue, 2014-11-11 at 15:48 -0600, Christopher Myers wrote: Just out of curiosity -
In the past it was usually recommended to have a separate /boot partition, and for that partition to be the first one of the disk. However, I've noticed that in openSuSE 13.2 and SLES 12 that the default now is to not create this partition, and to instead install the bootcode into "/" directly, with /boot being a subfolder of the root partition.
Has something changed with regards to "best practices," or is there another reason that this is the default now?
Just wanting to make sure that I build my systems correctly with the new versions :)
I presume (from the top of my head) it has something to do with (u)efi. Some installation create a separate vfat (brrr) partition and mount it upon /boot/efi. Perhaps it is considered too dangerous to leave kernels and initrd visible to windows, hence they moved it elsewhere... That would make sense then. thanks for the explanation :) One more question - what are all the subvolume objects listed on the disk screen now? Is it a result of the move to btrfs? hw -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 2014-11-11 23:52, Christopher Myers wrote:
Hans Witvliet 11/11/14 4:40 PM >>> On Tue, 2014-11-11 at 15:48 -0600, Christopher Myers wrote:
I presume (from the top of my head) it has something to do with (u)efi. Some installation create a separate vfat (brrr) partition and mount it upon /boot/efi. Perhaps it is considered too dangerous to leave kernels and initrd visible to windows, hence they moved it elsewhere...
That would make sense then. thanks for the explanation :)
No, it does not. It is not related at all.
One more question - what are all the subvolume objects listed on the disk screen now? Is it a result of the move to btrfs?
Yes. Not a result, a feature. -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)
Hans Witvliet wrote:
On Tue, 2014-11-11 at 15:48 -0600, Christopher Myers wrote:
Just out of curiosity -
In the past it was usually recommended to have a separate /boot partition, and for that partition to be the first one of the disk. However, I've noticed that in openSuSE 13.2 and SLES 12 that the default now is to not create this partition, and to instead install the bootcode into "/" directly, with /boot being a subfolder of the root partition.
Has something changed with regards to "best practices," or is there another reason that this is the default now?
Best practice changes? No, Suse changes, yes. :-| (str8-face) As near as I can tell suse pol is to put root on btrfs, and home on xfs. Only two partitions are mentioned... using a "subfolder" (instead of a subdirectory) on btrfs, I believe has separate volume-like features, but btrfs is bit like lvm, in that it's more efficient for there to be 1 vg and allocate lvs's out of that as needed (especially if wanting to use 'thin' volumes, which like btrfs will allows sharing of same content between volumes (or in btrfs, between different folders). This is from incidental contact with btrfs documentation and a bit more lvm contact, but a reading-only contact about thin-volumes using shared pools with lvm. Someone may have more precise (or correct) information as I've only been paying attention the advances on a back burner..
Just wanting to make sure that I build my systems correctly with the new versions :)
I presume (from the top of my head) it has something to do with (u)efi. Some installation create a separate vfat (brrr) partition and mount it upon /boot/efi.
I am not sure, but I thought the suggested layout was the same for standard and uefi boot -- except that uefi will require one or more administratively-required partitions at the beginning of a disk, -- but again, no direct knowledge. -l -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
Cool cool, thanks guys :) Definitely appreciate it, and the chance to build my knowledge about these new changes :) -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
Christopher Myers wrote:
Just out of curiosity -
In the past it was usually recommended to have a separate /boot partition, and for that partition to be the first one of the disk. However, I've noticed that in openSuSE 13.2 and SLES 12 that the default now is to not create this partition, and to instead install the bootcode into "/" directly, with /boot being a subfolder of the root partition.
Has something changed with regards to "best practices," or is there another reason that this is the default now?
ISTR that way back in time, boot loaders had trouble reading past the first 1024 cylinders of the disk. That limitation was lifted long ago, but having a separate /boot partition was a way of working around it. -- Per Jessen, Zürich (7.2°C) http://www.hostsuisse.com/ - virtual servers, made in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On Wed, 2014-11-12 at 07:20 +0100, Per Jessen wrote:
Christopher Myers wrote:
Just out of curiosity -
In the past it was usually recommended to have a separate /boot partition, and for that partition to be the first one of the disk. However, I've noticed that in openSuSE 13.2 and SLES 12 that the default now is to not create this partition, and to instead install the bootcode into "/" directly, with /boot being a subfolder of the root partition.
Has something changed with regards to "best practices," or is there another reason that this is the default now?
ISTR that way back in time, boot loaders had trouble reading past the first 1024 cylinders of the disk. That limitation was lifted long ago, but having a separate /boot partition was a way of working around it.
What you wrote is _ONE_ reason for having /boot on a separate partition. The 1024 cylinder limitation is indeed a old relic. However, there is still a good reason for doing so: If you need full disk encryption (as in: root + swap), you still need /boot in an unencrypted area, because grub needs access to the kernel and initrd Hans -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
В Wed, 12 Nov 2014 23:58:35 +0100 Hans Witvliet <suse@a-domani.nl> пишет:
On Wed, 2014-11-12 at 07:20 +0100, Per Jessen wrote:
Christopher Myers wrote:
Just out of curiosity -
In the past it was usually recommended to have a separate /boot partition, and for that partition to be the first one of the disk. However, I've noticed that in openSuSE 13.2 and SLES 12 that the default now is to not create this partition, and to instead install the bootcode into "/" directly, with /boot being a subfolder of the root partition.
Has something changed with regards to "best practices," or is there another reason that this is the default now?
ISTR that way back in time, boot loaders had trouble reading past the first 1024 cylinders of the disk. That limitation was lifted long ago, but having a separate /boot partition was a way of working around it.
What you wrote is _ONE_ reason for having /boot on a separate partition. The 1024 cylinder limitation is indeed a old relic.
However, there is still a good reason for doing so: If you need full disk encryption (as in: root + swap), you still need /boot in an unencrypted area, because grub needs access to the kernel and initrd
grub2 used in 13.2 may be able to read it (it supports LUKS encryption). -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 2014-11-13 04:34, Andrei Borzenkov wrote:
В Wed, 12 Nov 2014 23:58:35 +0100 Hans Witvliet <suse@a-domani.nl> пишет:
grub2 used in 13.2 may be able to read it (it supports LUKS encryption).
LOL. When will we have a Linux in grub area competition? ;-p -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)
On 2014-11-12 23:58, Hans Witvliet wrote:
On Wed, 2014-11-12 at 07:20 +0100, Per Jessen wrote:
What you wrote is _ONE_ reason for having /boot on a separate partition. The 1024 cylinder limitation is indeed a old relic.
However, there is still a good reason for doing so: If you need full disk encryption (as in: root + swap), you still need /boot in an unencrypted area, because grub needs access to the kernel and initrd
The OP asked about «separate /boot partition, and for that partition to be the first one of the disk.» The reason you mention, which I also posted about this morning, doesn't care if it is the first or the last partition. -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 2014-11-11 22:48, Christopher Myers wrote:
Just out of curiosity -
In the past it was usually recommended to have a separate /boot partition, and for that partition to be the first one of the disk.
That recommendation is over a decade obsolete and invalid. Specially that about being the first partition. The old need for /boot being at the start of the disk was that some earlier bioses could not boot beyond the track number 1024, or beyond certain size. There have been several limitations over the decades of PC history. So the trick was to place /boot as a small partition snugged out from somewhere before that point: not necessarily the first partition.
However, I've noticed that in openSuSE 13.2 and SLES 12 that the default now is to not create this partition, and to instead install the bootcode into "/" directly, with /boot being a subfolder of the root partition.
And that has been the default for a over a decade now, and has not changed. With some exceptions⁽¹⁾
Has something changed with regards to "best practices," or is there another reason that this is the default now?
No. At least not in openSUSE. (1) Exceptions for needing a /boot partition: a) some configurations with LVM, RAID, and/or encryption. b) some partition types had problems embedding grub inside; XFS had this problem, later solved it. c) some partition types lost the ability to be valid for certain features; for instance, root on reiserfs takes a very long time to replay the journal on memory on recovery from hibernation. Grub since certain update takes minutes to start the hibernated system in this case. d) btrfs now may have some problems embedding grub2 code, apparently when the disk has a layout that starts the first partition on sector 63 instead than on the first megabyte as is the current system. This is a problem on some 13.2 installs on disks shared with some windows partitions (there should be a note in the release notes about this) All the above is with traditional MBR partitions, not with GPT and/or UEFI. In that case, the layout is somewhat different. That is, there is a special "boot" partition of a special fat type needed by uefi, one or more, shared or not between different oses, there may be, or not, a linux "/boot" partition, and the normal "/" root partition. I will not describe that layout in detail, not my area of knowledge. - -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar) -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iEYEARECAAYFAlRjcL4ACgkQtTMYHG2NR9Ut+wCffthiENtonFISALGe1fPp5gpI 4ccAn34wCqMUDjXljP/0OvCRv9yd2JQl =ljjE -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
participants (7)
-
Andrei Borzenkov -
Carlos E. R. -
Carlos E. R. -
Christopher Myers -
Hans Witvliet -
Linda Walsh -
Per Jessen