Subject: Re: log-structured file system
To: Greg Cronau <>
From: Chris G. Demetriou <cgd@postgres.Berkeley.EDU>
List: current-users
Date: 06/13/1994 14:13:48
>     The EFS(Extended File System???) or "Clustering file system" seems,
> by description, to be an extension of the standard "Fast File System"
> FFS or UFS. Will the clustering file system be able to access old style
> UFS partitions, or will newfs'ing be required?

clustering in the 4.4BSD FS is implemented independent of disk layout;
basically, it tries to lay things out in clusters, but the rest of the
file system looks the same.

Well, that was pretty unclear.  8-)  What i mean is something like:
the locations of the blocks change for performance reasons, but
all the rest of the data structures (e.g. the inodes) stay the same
with clustering and without, so a FFS can be clustered or not w/o
changing the on-disk format.

however, there have been other changes to the file systems that
require that newly-newfs'd fs's be used with newer kernel.  (e.g.
32-bit uid's and gid's.)  You can still use your old file systems
with new kernels with no problems, though once you've decided that
a new kernel is always goign to be running on your machine, you
should 'fsck -c 2' them.