DragonFly kernel List (threaded) for 2008-06
Re: HAMMER Update - 28 June 2008
:With pseudo-fs hammer, will i be able to specify size for each pseudo
:filesystem? Is this basically going to eliminate the need for disklabels?
:That would be fantastic. ie. single real hammer filesystem, with a pseudo
:filesystems for /usr, /home and friends and be able to shrink them/expand
:them as needed. Will these pseudo file systems be specified in fstab like
:normal, and able to mount/umount them as needed?
It isn't that complex, at least not for the first release. The
pseudo-fs's are just special subdirectories within a normal HAMMER
filesystem. These subdirectories have special characteristics, such
as having their own inode numbering space, that allows them to be
used as mirroring targets.
I did consider making pseudo-fs's formally mountable but it would
be a real mess to do it. You *can* in fact mount them separately
using NULL mounts (mount_null). In DragonFly null mounts are just as
efficient as normal mounts, and can be specified in /etc/fstab after
the main HAMMER mount.
The pseudo-fs's use the same space management as the primary mount
right now. I am not tracking space use on a per-pseudo-fs basis.