4 ms·

Does anyone know the reasoning for Ext3 to be supported but not Ext4? From the article, "A notable omission is Ext4; read-only functionality is supported for m

by DASD 14y ago

Does anyone know the reasoning for Ext3 to be supported but not Ext4? From the article, "A notable omission is Ext4; read-only functionality is supported for migrating to a different filesystem. Full read-write support is available with the ext4-writeable KMPkernel module from the SLES11-Extras repository, but it is not supported."

andrewcooke 14y ago
that's odd. thought ext4 was supported in opensuse (article is about enterprise suse). in fact just checked - it's the default if i add a new logical vol in yast, in 12.2 (current release).
ars 14y ago
Ext3 is basically the venerable ext2 plus journaling. It's not a dramatic change. Ext4 is more or less a rewrite.
- tytso 14y ago
  That's not true. The changes from ext4 to ext3 are evolutionary, not revolutionary. There is full backwards compatibility, and there's still a lot of the original ext3 code in ext4 (in particular, we still support old-fashioned indirect blocks in ext4, even though it's not the default, and we do that using a copy of the ext3 code). If you look in the git history, you can see all of the changes as we added new features into ext3 during the course of the ext4 development.
- mercurial 14y ago
  > Despite the fact that Ext4 adds a number of compelling features to the filesystem, T'so doesn't see it as a major step forward. He dismisses it as a rehash of outdated "1970s technology" and describes it as a conservative short-term solution. He believes that the way forward is Oracle's open source Btrfs filesystem, which is designed to deliver significant improvements in scalability, reliability, and ease of management. From http://arstechnica.com/information-technology/2009/04/linux-collaboration-summit-the-kernel-panel/ http://arstechnica.com/information-technology/2009/04/linux-...
tytso 14y ago
SLES decided several years ago not to support ext4. Their reasoning was that once they started supporting ext4, they would be committed to support it for ten years (since they are an enterprise distro). At the time, they didn't have the staffing levels to support another file system, and they assumed that btrfs would be coming down the pike soon. As it turns out btrfs took a bit longer for them to stablize than they had counted upon, but that's why they made the decision they did when SLES 11 was first released. And now you know the rest of the story. :-)

by DASD 14y ago

andrewcooke 14y ago

that's odd. thought ext4 was supported in opensuse (article is about enterprise suse). in fact just checked - it's the default if i add a new logical vol in yast, in 12.2 (current release).

ars 14y ago

Ext3 is basically the venerable ext2 plus journaling. It's not a dramatic change. Ext4 is more or less a rewrite.

tytso 14y ago
That's not true. The changes from ext4 to ext3 are evolutionary, not revolutionary. There is full backwards compatibility, and there's still a lot of the original ext3 code in ext4 (in particular, we still support old-fashioned indirect blocks in ext4, even though it's not the default, and we do that using a copy of the ext3 code). If you look in the git history, you can see all of the changes as we added new features into ext3 during the course of the ext4 development.
mercurial 14y ago
> Despite the fact that Ext4 adds a number of compelling features to the filesystem, T'so doesn't see it as a major step forward. He dismisses it as a rehash of outdated "1970s technology" and describes it as a conservative short-term solution. He believes that the way forward is Oracle's open source Btrfs filesystem, which is designed to deliver significant improvements in scalability, reliability, and ease of management. From http://arstechnica.com/information-technology/2009/04/linux-collaboration-summit-the-kernel-panel/ http://arstechnica.com/information-technology/2009/04/linux-...

tytso 14y ago

SLES decided several years ago not to support ext4. Their reasoning was that once they started supporting ext4, they would be committed to support it for ten years (since they are an enterprise distro). At the time, they didn't have the staffing levels to support another file system, and they assumed that btrfs would be coming down the pike soon. As it turns out btrfs took a bit longer for them to stablize than they had counted upon, but that's why they made the decision they did when SLES 11 was first released. And now you know the rest of the story. :-)