[OpenAFS] Salvager did not run automatically on solaris 9, 1.4.1-rc10

Rainer Toebbicke rtb@pclella.cern.ch
Tue, 18 Apr 2006 10:18:28 +0200


Jeffrey Hutzelman wrote:

> 
> 
> I have to admit I'm a little curious why you switched from inode to 
> namei on a Solaris server...
> 

A little bit off-topic:

Admittedly I frowned myself for years at voices promoting the use of 
the namei fileserver in favour of the inode one, until...

on the inode fileserver the inc(), dec() operations always translate 
into real I/Os. You cannot do a lot such operations per second, at 
least I did not find out how.

This means that cloning (and therefore moving, backing up, ...) 
volumes is intrinsically slow. With the namei fileserver the speedup 
is tremendous once you group the intervening fsyncs(). This is 
relevant for operating a service where people think in volumes of 
several hundred thousand files. I am still frowning at the otherwise 
unproductive overhead the namei fileserver induces at every operation.

Hence only our 1.2.X Solaris servers are still running the inode 
fileserver, the 1.4.X were switched to namei with up to now (touch 
wood) no ill effects.

Now, strictly speaking this is an argument in favour of the link count 
file that the namei fileserver uses instead of using the inode 
reference counts. I could well imagine the same technique in the inode 
fileserver.


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Rainer Toebbicke
European Laboratory for Particle Physics(CERN) - Geneva, Switzerland
Phone: +41 22 767 8985       Fax: +41 22 767 7155