On Sat, 2006-04-22 at 03:39, Tomas ?gren wrote: > > OK, so without much effort I can halve the disk IO from 6.5G to just > > over 3G, and cut the zone package install time from over 6 minutes to > > under 4. Given the crudeness of the hack, I wouldn't be surprised if it > > could > > be improved further. > > My question is: Why the ... should the entire file be rewritten over and over > again when only a small fraction of it is changed (when you install another > package)? If the same format is needed at the end of the install, why not let > each package install put its contents into separate files and when it's all > done, merge them. Writing 6.5GB for a file that is about 1/1000th of that is > just insane..
Well, yes, that's definitely not optimal. However, there are a couple of things to bear in mind: (1) the actual cost of this insanity is relatively small (which certainly surprised me), and (2) doing it this way allows certain optimizations elsewhere in the packaging system, so that doing it some other way has a cost that needs to be quantified. Handling a thousand separate files (as an example) involves more overhead than looking after just the one and - as currently structured - installing a package involves checking all the contents of all currently installed packages. Currently, that would be significantly more expensive than the current lunacy, although that doesn't have to be the case. > For instance Debian has a separate file for each package and that seems to > work just fine.. (and the install time is just a fraction of Solaris install > time) The contents file isn't the difference - it's a 10% effect. It would, however, be interesting to see a breakdown of where the installation time in debian is being spent. -- -Peter Tribble L.I.S., University of Hertfordshire - http://www.herts.ac.uk/ http://www.petertribble.co.uk/ - http://ptribble.blogspot.com/
