[OpenAFS-devel] more on the 2.2.18pre17 SMP cpu hog/etc.

Nathan Neulinger nneul@umr.edu
Fri, 01 Dec 2000 16:09:51 -0600

"Patrick J. Hennessey" wrote:
> On Thu, 30 Nov 2000, Nathan Neulinger wrote:
> > After a very long time, it actually finished and mounted /afs.
> The first time afsd runs it has to create a bunch of inode cache entries
> and dirs.  This is noticably inefficient, especially if you configure a
> large cache.  If you wait it out afsd will start much quicker the second
> time around.

I've been running AFS for years. The cache was already built, and even
if it hadn't been, the cache creation has never (on any platform I've
used afs on - even slow p.o.s. aix boxes) driven the machine into the
ground. Starting afs on my home box manually results in X being
virtually unusable - and this is on a dual-850-piii w/ 512MB of memory.

In any case, the slowdown occurs AFTER the cache files are created,
during the second pass through the cache activating the cache inodes -
where it potentially creates/checks the contents of the cache files. 

BTW, this is on reiserfs, I've got linux x86 machines at work that
create 350 MB afs caches from scratch (empty filesystem) in a matter of
30-40 SECONDS. This slowdown resulted in afsd w/ a 3.5MB afs cache
taking 10 MINUTES to start.

-- Nathan

Nathan Neulinger                       EMail:  nneul@umr.edu
University of Missouri - Rolla         Phone: (573) 341-4841
CIS - Systems Programming                Fax: (573) 341-4216