[opensuse-kernel] Using ext4 driver for ext2 filesystem in Factory
Hello, we are figuring out upstream how to eventually get rid of maintaing three code bases of ext2, ext3, and ext4 in parallel. These days ext4 kernel driver is able to handle both ext2 and ext3 filesystems in a backward compatible manner - i.e., you can mount, access, modify the filesystem with ext4 driver and then still be able to use it with the old ext2 driver. So I'd think that we could try changing config of our kernel in Factory so that ext4 driver is used for ext2 filesystem and see whether something breaks or not. Do people have any opinion on this? Honza -- Jan Kara <jack@suse.cz> SUSE Labs, CR -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
On Thu, 7 Apr 2011 20:57:12 +0200, Jan Kara <jack@suse.cz> wrote:
we are figuring out upstream how to eventually get rid of maintaing three code bases of ext2, ext3, and ext4 in parallel. These days ext4 kernel driver is able to handle both ext2 and ext3 filesystems in a backward compatible manner - i.e., you can mount, access, modify the filesystem with ext4 driver and then still be able to use it with the old ext2 driver. So I'd think that we could try changing config of our kernel in Factory so that ext4 driver is used for ext2 filesystem and see whether something breaks or not.
Do people have any opinion on this?
Go for it (American slang for do it). -- Free web mail, POP3, and SMTP http://www.beewyz.com/freeaccounts.php -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
On Thu, 7 Apr 2011 20:57:12 +0200 Jan Kara <jack@suse.cz> wrote:
so that ext4 driver is used for ext2 filesystem and see whether something breaks or not.
Do people have any opinion on this?
Just make sure that no filesystem is converted by accident (not sure if that could happen with the ext4 driver). -- Stefan Seyfried "Dispatch war rocket Ajax to bring back his body!" -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 04/07/2011 03:57 PM, Stefan Seyfried wrote:
On Thu, 7 Apr 2011 20:57:12 +0200 Jan Kara <jack@suse.cz> wrote:
so that ext4 driver is used for ext2 filesystem and see whether something breaks or not.
Do people have any opinion on this?
Just make sure that no filesystem is converted by accident (not sure if that could happen with the ext4 driver).
tune2fs is AFAIK the only way to enable incompatible features (like a journal or extents) on an ext[234] file system. - -Jeff - -- Jeff Mahoney SUSE Labs -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.17 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org/ iEYEARECAAYFAk2eIVUACgkQLPWxlyuTD7KzGQCbBvl0vZssZPp2FE1j6J1smIGO ydAAoKVw0hqBafFeEil+yINulgfWwqlB =SncB -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
On 4/7/2011 2:57 PM, Jan Kara wrote:
Hello,
we are figuring out upstream how to eventually get rid of maintaing three code bases of ext2, ext3, and ext4 in parallel. These days ext4 kernel driver is able to handle both ext2 and ext3 filesystems in a backward compatible manner - i.e., you can mount, access, modify the filesystem with ext4 driver and then still be able to use it with the old ext2 driver. So I'd think that we could try changing config of our kernel in Factory so that ext4 driver is used for ext2 filesystem and see whether something breaks or not.
Do people have any opinion on this?
Honza
Is ext4 driver as fast, stable, small/simple for embedded, matured for over 10 years as ext2 driver ? Everything else might be green but that last is hard to address other than by "Feel free to use old kernel and old anything else that doesn't work on that old kernel.". Also more than one implementation of a core thing is not always bad. It allows a user to discover that a problem seen in one turns out not to exist in the other. I guess neither of these is really worth inhibiting progress. Just thoughts. Same arguments applied when ata took over handling all ide. -- bkw -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 04/07/2011 04:04 PM, Brian K. White wrote:
On 4/7/2011 2:57 PM, Jan Kara wrote:
Hello,
we are figuring out upstream how to eventually get rid of maintaing three code bases of ext2, ext3, and ext4 in parallel. These days ext4 kernel driver is able to handle both ext2 and ext3 filesystems in a backward compatible manner - i.e., you can mount, access, modify the filesystem with ext4 driver and then still be able to use it with the old ext2 driver. So I'd think that we could try changing config of our kernel in Factory so that ext4 driver is used for ext2 filesystem and see whether something breaks or not.
Do people have any opinion on this?
Honza
Is ext4 driver as fast, stable, small/simple for embedded, matured for over 10 years as ext2 driver ? Everything else might be green but that last is hard to address other than by "Feel free to use old kernel and old anything else that doesn't work on that old kernel.".
Also more than one implementation of a core thing is not always bad. It allows a user to discover that a problem seen in one turns out not to exist in the other.
This actually ends up not working out that well. What ends up happening is that bugs are fixed in the version that is most current, now ext4 but this happened with ext3 as well, and perhaps not in older versions. - -Jeff - -- Jeff Mahoney SUSE Labs -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.17 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org/ iEYEARECAAYFAk2eIa4ACgkQLPWxlyuTD7JXfgCfezb6BVgaaCg0aswFY0brqM3L a74AmgNhDCQtjI9gMtJdCRdCEh4AMRNN =6zm1 -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
<resend in plain text> On Thu, Apr 7, 2011 at 2:57 PM, Jan Kara <jack@suse.cz> wrote:
Hello,
we are figuring out upstream how to eventually get rid of maintaing three code bases of ext2, ext3, and ext4 in parallel. These days ext4 kernel driver is able to handle both ext2 and ext3 filesystems in a backward compatible manner - i.e., you can mount, access, modify the filesystem with ext4 driver and then still be able to use it with the old ext2 driver. So I'd think that we could try changing config of our kernel in Factory so that ext4 driver is used for ext2 filesystem and see whether something breaks or not.
Do people have any opinion on this?
Honza
I think it is a good idea. It is something easily reverted late in the release cycle, so there is not that much danger from a release cycle perspective. Conceivably it could eat a filesystem or two, but I have often heard it said that factory can do that, especially very early in the cycle like we are right now. fyi: on a smaller scale I will be asking the same thing about a patch to mkfs.ext4 that has been in use for CTERA production for a year or so. It has been tested heavily in that environment, but not in a broad set of environments. Thoughts about doing that in the short term would also be welcome. fyi: Jan, I'm just proposing to package Amir Goldstein's patch for e2fsprogs. My hope is to get the full next4 kernel module into factory with experimental status once factory moves to 2.6.39. Greg -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
Hello,
we are figuring out upstream how to eventually get rid of maintaing
On Thu, 7 Apr 2011 20:57:12 +0200, Jan Kara <jack@suse.cz> wrote: three
code bases of ext2, ext3, and ext4 in parallel. These days ext4 kernel driver is able to handle both ext2 and ext3 filesystems in a backward compatible manner - i.e., you can mount, access, modify the filesystem with ext4 driver and then still be able to use it with the old ext2 driver. So I'd think that we could try changing config of our kernel in Factory so that ext4 driver is used for ext2 filesystem and see whether something breaks or not.
Do people have any opinion on this?
Honza -- Jan Kara <jack@suse.cz> SUSE Labs, CR
Hello Some thoughts on this If filesystem is not in use e.g overnight /out of business hours - tar existing files up to somewhere else provided there is enough free target space - Reformat {ext2, ext3}partition to ext4 - Restore files to the reformatted partition - do the smaller partitions first [df -h] will get the sizes of partitions - unsure if dir/file permissions are preserved though. - Prehaps use cron to assist to do the job Good luck Glenn -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
On Fri 08-04-11 13:15:54, doiggl@velocitynet.com.au wrote:
Hello,
we are figuring out upstream how to eventually get rid of maintaing
On Thu, 7 Apr 2011 20:57:12 +0200, Jan Kara <jack@suse.cz> wrote: three
code bases of ext2, ext3, and ext4 in parallel. These days ext4 kernel driver is able to handle both ext2 and ext3 filesystems in a backward compatible manner - i.e., you can mount, access, modify the filesystem with ext4 driver and then still be able to use it with the old ext2 driver. So I'd think that we could try changing config of our kernel in Factory so that ext4 driver is used for ext2 filesystem and see whether something breaks or not.
Do people have any opinion on this?
Honza -- Jan Kara <jack@suse.cz> SUSE Labs, CR
Some thoughts on this If filesystem is not in use e.g overnight /out of business hours - tar existing files up to somewhere else provided there is enough free target space - Reformat {ext2, ext3}partition to ext4 - Restore files to the reformatted partition - do the smaller partitions first [df -h] will get the sizes of partitions - unsure if dir/file permissions are preserved though. - Prehaps use cron to assist to do the job Yeah, sure you can migrate the filesystem this way and I think it might be desirable for most users (possibly then run ext4 in nojournal mode) but I understand some people might wish to stay with ext2 for legacy reasons.
Honza -- Jan Kara <jack@suse.cz> SUSE Labs, CR -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 04/07/2011 11:15 PM, doiggl@velocitynet.com.au wrote:
Hello,
we are figuring out upstream how to eventually get rid of maintaing
On Thu, 7 Apr 2011 20:57:12 +0200, Jan Kara <jack@suse.cz> wrote: three
code bases of ext2, ext3, and ext4 in parallel. These days ext4 kernel driver is able to handle both ext2 and ext3 filesystems in a backward compatible manner - i.e., you can mount, access, modify the filesystem with ext4 driver and then still be able to use it with the old ext2 driver. So I'd think that we could try changing config of our kernel in Factory so that ext4 driver is used for ext2 filesystem and see whether something breaks or not.
Do people have any opinion on this?
Honza -- Jan Kara <jack@suse.cz> SUSE Labs, CR
Hello Some thoughts on this If filesystem is not in use e.g overnight /out of business hours - tar existing files up to somewhere else provided there is enough free target space - Reformat {ext2, ext3}partition to ext4 - Restore files to the reformatted partition - do the smaller partitions first [df -h] will get the sizes of partitions - unsure if dir/file permissions are preserved though. - Prehaps use cron to assist to do the job
This is actually unnecessary unless you want to do things like use extents on existing files. The format is forward-compatible so you can use tune2fs to enable the features added by newer versions. - -Jeff - -- Jeff Mahoney SUSE Labs -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.17 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org/ iEYEARECAAYFAk2jEL4ACgkQLPWxlyuTD7L/kgCfSTvh26xJZULEtQdzc/jSMDgs q4kAniEK0bb885cxv7Vk9YSZQNs1pF6u =GXDe -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
Hi Jan, On Thursday 07 April 2011 08:57:12 pm Jan Kara wrote:
Hello,
we are figuring out upstream how to eventually get rid of maintaing three code bases of ext2, ext3, and ext4 in parallel. These days ext4 kernel driver is able to handle both ext2 and ext3 filesystems in a backward compatible manner - i.e., you can mount, access, modify the filesystem with ext4 driver and then still be able to use it with the old ext2 driver. So I'd think that we could try changing config of our kernel in Factory so that ext4 driver is used for ext2 filesystem and see whether something breaks or not.
Do people have any opinion on this?
Wouldn't it be a safest path to replace the use cases of ext2 with ext_3_? It's way more mature than ext4, and presumably people have already been using ext3 to mount ext2 partitions for years. As you didn't mention a plan to drop the ext3 driver, I'd use it for ext2. IMHO it only makes sense to use the ext4 driver for ext2 partitions if we plan to drop the ext2 _and_ ext3 drivers, and use the ext4 driver for all three partition types. Just my two I-don't-know-a-thing-about-file-systems cents. -- Jean Delvare Suse L3 -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
On Thursday 07 April 2011 08:57:12 pm Jan Kara wrote:
Hello,
we are figuring out upstream how to eventually get rid of maintaing three code bases of ext2, ext3, and ext4 in parallel. These days ext4 kernel driver is able to handle both ext2 and ext3 filesystems in a backward compatible manner - i.e., you can mount, access, modify the filesystem with ext4 driver and then still be able to use it with the old ext2 driver. So I'd think that we could try changing config of our kernel in Factory so that ext4 driver is used for ext2 filesystem and see whether something breaks or not.
Do people have any opinion on this?
Wouldn't it be a safest path to replace the use cases of ext2 with ext_3_? It's way more mature than ext4, and presumably people have already been using ext3 to mount ext2 partitions for years. There's a problem with ext3 replacing ext2 as ext3 adds journaling which adds visible performance overhead. I suppose people who had not migrated from ext2 to ext3 by now either care about the performance difference or just don't care about anything all :). In both cases ext4 should be OK with
As you didn't mention a plan to drop the ext3 driver, I'd use it for ext2. IMHO it only makes sense to use the ext4 driver for ext2 partitions if we plan to drop the ext2 _and_ ext3 drivers, and use the ext4 driver for all three partition types. Well, there are plans for dropping ext3 as well. I just want to do it step by step. And ext3 is used by *much* more users than ext2 these days so
Hi Jean, On Fri 08-04-11 19:36:56, Jean Delvare wrote: them. I agree that ext3 is more mature than ext4 but by now ext4 is pretty stable as well so I wouldn't be afraid to offer it to openSUSE users as a replacement. In fact, ext2 codebase bitrots slowly because noone really cares about it so migrating to ext4 is not that bad idea from stability POV either. that's why I want to be extra careful there... Honza -- Jan Kara <jack@suse.cz> SUSE Labs, CR -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
Hi Jean,
On Fri 08-04-11 19:36:56, Jean Delvare wrote:
On Thursday 07 April 2011 08:57:12 pm Jan Kara wrote:
Hello,
we are figuring out upstream how to eventually get rid of maintaing three code bases of ext2, ext3, and ext4 in parallel. These days ext4 kernel driver is able to handle both ext2 and ext3 filesystems in a backward compatible manner - i.e., you can mount, access, modify the filesystem with ext4 driver and then still be able to use it with the old ext2 driver. So I'd think that we could try changing config of our kernel in Factory so that ext4 driver is used for ext2 filesystem and see whether something breaks or not.
Do people have any opinion on this?
Wouldn't it be a safest path to replace the use cases of ext2 with ext_3_? It's way more mature than ext4, and presumably people have already been using ext3 to mount ext2 partitions for years.
There's a problem with ext3 replacing ext2 as ext3 adds journaling which adds visible performance overhead. I suppose people who had not migrated from ext2 to ext3 by now either care about the performance difference or just don't care about anything all :). In both cases ext4 should be
Or are using flash cards :-). -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
On Fri 08-04-11 19:36:56, Jean Delvare wrote:
On Thursday 07 April 2011 08:57:12 pm Jan Kara wrote:
Hello,
we are figuring out upstream how to eventually get rid of maintaing three code bases of ext2, ext3, and ext4 in parallel. These days ext4 kernel driver is able to handle both ext2 and ext3 filesystems in a backward compatible manner - i.e., you can mount, access, modify the filesystem with ext4 driver and then still be able to use it with the old ext2 driver. So I'd think that we could try changing config of our kernel in Factory so that ext4 driver is used for ext2 filesystem and see whether something breaks or not.
Do people have any opinion on this?
Wouldn't it be a safest path to replace the use cases of ext2 with ext_3_? It's way more mature than ext4, and presumably people have already been using ext3 to mount ext2 partitions for years.
There's a problem with ext3 replacing ext2 as ext3 adds journaling which adds visible performance overhead. I suppose people who had not migrated from ext2 to ext3 by now either care about the performance difference or just don't care about anything all :). In both cases ext4 should be
Or are using flash cards :-). Oh yeah, that's a good point (for other readers, some flash cards tend to have "interesting" properties invalidating assumptions any sane journalling filesystem has about the behavior of underlying device. Thus crashing in
On Fri 15-04-11 18:29:49, Pavel Machek wrote: the middle of write is going to corrupt filesystem on these regardless of journalling). But ext4 in nojournal mode should be fine in this case either :) Honza -- Jan Kara <jack@suse.cz> SUSE Labs, CR -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
On 4/15/2011 12:29 PM, Pavel Machek wrote:
Hi Jean,
On Fri 08-04-11 19:36:56, Jean Delvare wrote:
On Thursday 07 April 2011 08:57:12 pm Jan Kara wrote:
Hello,
we are figuring out upstream how to eventually get rid of maintaing three code bases of ext2, ext3, and ext4 in parallel. These days ext4 kernel driver is able to handle both ext2 and ext3 filesystems in a backward compatible manner - i.e., you can mount, access, modify the filesystem with ext4 driver and then still be able to use it with the old ext2 driver. So I'd think that we could try changing config of our kernel in Factory so that ext4 driver is used for ext2 filesystem and see whether something breaks or not.
Do people have any opinion on this?
Wouldn't it be a safest path to replace the use cases of ext2 with ext_3_? It's way more mature than ext4, and presumably people have already been using ext3 to mount ext2 partitions for years.
There's a problem with ext3 replacing ext2 as ext3 adds journaling which adds visible performance overhead. I suppose people who had not migrated from ext2 to ext3 by now either care about the performance difference or just don't care about anything all :). In both cases ext4 should be
Or are using flash cards :-).
Yeah I've been using ext2 for /boot on usb thumb drives but in my case that's just /boot, written so rarely and taking so little space I have to admit that for me it hardly matters what fs is used as long as grub can read it and linux can write it. -- bkw -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-kernel+help@opensuse.org
participants (9)
-
Brian K. White -
doiggl＠velocitynet.com.au -
Greg Freemyer -
Jan Kara -
Jean Delvare -
Jeff Mahoney -
Pavel Machek -
Stefan Seyfried -
Trifle Menot