Journalling FS and Soft Updates comparision

Julian Elischer julian at
Thu Feb 10 14:56:33 PST 2005

uh.. isn't this backwards?

Dan Nelson wrote:

>This is the big drawback to softupdates for me.  You run the risk of
>losing the last `sysctl kern.metadelay` seconds worth of files, because
>of all the state that softupdates keeps in RAM.

kern.filedelay: 30
kern.dirdelay: 29
kern.metadelay: 28

according to this we write the metadata first  and then the directory 
block and
then the file data..

This is just wrong. In softupdates you want to have your data down 
before you do
your metadata write,  and you need to have your directory block written 
last of all.
When I committed the softupdates code for Kirk, I think that the numbers 
data in 10 seconds, metadata in 15 and directory block in 20.
(from memory).

More information about the freebsd-fs mailing list