Christopher R. Hertel
crh at nts.umn.edu
Thu Mar 22 07:38:33 GMT 2001
> Over the last week or so I have been
> trying to
> discover exactly what the issue is with Adobe
> FrameMaker and SAMBA. I think I may be able to
> put my finger on it now. I hope someone of the
> SAMBA developer team will be able to take a look
> at the code and correct this if it is in fact a
> bug in the code.
> Users working on FrameMaker projects served from a
> *NIX box running SAMBA, (only tested this on IRIX,
> linux and Solaris) experience sub acceptable
> performance with page refresh/loads. The same
> projects served from a native NT file server
> allowed users to experience near local
> performance. The same projects served from the
> same *NIX box but via NFS (NFS service installed
> on NT client) seen near local performance.
> Indicating perhaps an application issue.
> The image format of choice by FrameMaker folk tend
> to be TIFFs. SAMBA it seems has a hard time
> opening Tiffs in an efficient manner. Replace the
> TIFFs with almost any other image file format and
> performance shoots threw the roof even if they are
> of the same size. (thankfully microsloth didn't
> use tiffs in any of the benchmarks they
> sponsored). In a high debug mode you can see
> SAMBA stuck in a routine that it seems to execute
> several times per TIF file. I also noticed if you
> reduce the TIF to 256 shades of gray things speed
> up considerably as well.
Which routine? That would help a lot.
My completely wild guess is that the reading of a TIFF file involves a lot
of random access, and that we are crossing some sort of buffer boundary.
I do not know how data is stored in a TIFF file, but the fact that a
change in pixel depth would change the read characteristics suggests to
me that deeper pixel depths require more reads on Samba's part.
Very, very wild guess.
Christopher R. Hertel -)----- University of Minnesota
crh at nts.umn.edu Networking and Telecommunications Services
Ideals are like stars; you will not succeed in touching them
with your hands...you choose them as your guides, and following
them you will reach your destiny. --Carl Schultz
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