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On Tue, Apr 10, 2012 at 6:00 AM, Stroller |
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<stroller@××××××××××××××××××.uk> wrote: |
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> |
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> On 9 April 2012, at 13:04, Canek Peláez Valdés wrote: |
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>>>> … |
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>>>> This means ext4 mandatory if you want to use it, and this (usually) |
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>>>> means GRUB2, which is still considered beta. |
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>>> |
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>> … |
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>> Interesting. Do you have extents enabled in the filesystem? Mine does: |
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>> |
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>> # tune2fs -l /dev/sda4 | grep features |
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>> Filesystem features: has_journal ext_attr resize_inode dir_index |
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>> filetype needs_recovery extent sparse_super large_file uninit_bg |
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> |
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> # df -Th |
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> Filesystem Type Size Used Avail Use% Mounted on |
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> rootfs rootfs 228G 5.8G 211G 3% / |
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> /dev/root ext4 228G 5.8G 211G 3% / |
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> devtmpfs devtmpfs 875M 212K 875M 1% /dev |
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> rc-svcdir tmpfs 1.0M 60K 964K 6% /lib64/rc/init.d |
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> cgroup_root tmpfs 10M 0 10M 0% /sys/fs/cgroup |
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> shm tmpfs 876M 0 876M 0% /dev/shm |
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> # tune2fs -l /dev/root | grep extent |
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> Filesystem features: has_journal ext_attr resize_inode dir_index filetype needs_recovery extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink |
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> |
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>> I was under the impression that GRUB legacy could not read ext4 |
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>> filesystems with extents enabled; that was the primary reason I |
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>> migrated to GRUB2. I believe there is a patch for GRUB legacy which |
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>> adds ext4+extents support, but I don't think Gentoo applies it. |
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> |
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> No idea where it comes from, but you can see for yourself now you know to look. |
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|
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OK, I went out and did my homework. GRUB legacy upstream doesn't |
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support ext4 partitions (using extents, of course; without extents, |
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they can be mounted as ext3), but Gentoo (as almost any other |
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distribution under the sun) applies a patch to support it. Actually, |
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it applies 37 patches, contained in grub-0.97-patches-1.12.tar.bz2, |
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one of them called 850_all_grub-0.97_ext4.patch, which says: |
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|
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Gentoo bug #250829 - Include support for booting from ext4 partitions. |
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|
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This is the respun and tested patch adapted from |
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http://code.google.com/p/grub4ext4/ so that it will apply with the rest of the |
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Gentoo patches. |
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|
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Tested with: |
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/boot on ext2 |
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/boot on ext3 |
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/boot on ext4 |
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/ on ext4 (no seperate /boot) |
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|
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Patch ported by Diego E. Pettenò (flameeyes) |
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Testing by Robin H. Johnson (robbat2) |
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|
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Signed-off-by: Diego E. 'Flameeyes' Pettenò <flameeyes@g.o> |
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Signed-off-by: Robin H. Johnson <robbat2@g.o> |
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|
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So mistery solved: GRUB legacy in Gentoo supports ext4, but it differs |
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from upstream. When I was doing research for converting my filesystem |
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to ext4, everywhere I looked it said that GRUB legacy doesn't support |
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ext4... because it doesn't. Gentoo patches the sources, but upstream |
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GRUB legacy does not support ext4. |
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|
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So I can finally stop telling people to migrate to GRUB2 if they want |
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to use ext4. Thanks Stroller. |
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|
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Regards. |
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-- |
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Canek Peláez Valdés |
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Posgrado en Ciencia e Ingeniería de la Computación |
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Universidad Nacional Autónoma de México |
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