Re: journaling filesystem

stephen farrell (stephen@farrell.org)
12 Jun 1997 01:43:33 -0500


"Theodore Y. Ts'o" <tytso@MIT.EDU> writes:

> Date: Wed, 11 Jun 1997 14:16:15 +0800 (GMT)
> From: Orlando Andico <orly@gibson.eee.upd.edu.ph>
>
> i just read about the veritas filesystem (well, yeah, it existed a long
> time ago..) and was wondering if journaling is ever going to be added to
> ext2fs. what must be added/modified to the driver code to support an
> intent log? i think basic journaling code would "only" require addition of
> an intent log (where?) and add reading of this log to e2fsck..
>
> Adding journalling isn't so simple. One, you need ordered writes, which
> is something the low-level block device interface doesn't provide.
> Secondly, you have to worry about performance, which is hard to do while
> still having the ordering semantics.
>
> - Ted

How important do you consider a good journaling fs for linux? It
seems to me like journalling would be most important for something
like a huge ftp site.... but ftp.freebsd.org is now 106GB of disk
space. It takes me at least 1 minute to fsck a 1.5 GB partition.
That means to fsck this disk farm at ftp.freebsd.org after a crash,
it's going to take around an _hour_, which seems unacceptable by any
standard.

But somehow they get away with this. Maybe they mount most of the
disks read-only? Perhaps I'll write and ask.

Dunno--just thinking out loud.