"Logging" or "Log structured" file systems with news spool.

"Logging" or "Log structured" file systems with news spool.

Post by Bill Davids » Sat, 22 Apr 1995 04:00:00

(I've included comp.arch.storage and comp.databases in hopes of getting
info from people who know about large file systems with lots of small

We're putting together a new news machine since our old one, which was
a large general server is going to be retired in a few months.  Instead
of burdening our newer servers with news, we want to set up a
workstation (Sparc 5 w/Solaris 2.4) dedicated to news.

I figure that anything I can do to speed up disk performance in the
news spool disk is worth a fair amount of effort.  News is pretty close
to a worst case scenario for disk performance due to the small files
(3.5KB average, 2KB typical) and the fact that news requires tons of
random seeking.  I'd like to plan this system so that it can easily
handle the news load for several years as well as support about 100
readers.  Right now my news spool contains about three-hundred-
thousand files and I expire news after 5 days.

I plan to move to the INN transport software with this new news server.

I've been researching things and I believe that using a log structured
file system (provided by Veritas Volume Manager) can probably buy me
some extra performance, particularly during news reception (lots of
small writes).  Is this correct?  I believe Sun's Online: Disksuite 3.0
provides a logging UFS.  Might this increase performance if I decide
not to use Veritas for some reason?

Also, we'll be using multiple 1GB disks.  I suspect that using multiple
disks with large stripe (interlace) sizes will also be a win since
individual articles end up on one disk or another but not spread over
each except for the relatively rare large article.  I'm hoping this
will reduce the individual seeking that has to be done on each disk.
Even if it doesn't buy me any performance (though I hope it will) I'm
hoping this will at least reduce wear on the disks by distributing the

I'd appreciate any comments or advice on this subject.

--Bill Davidson