Nicholas Jones wrote: >> Does anyone here run a /usr/portage mounted over NFS >> over an ADSL link, like 1.5x256? > >> I think this is a good argument for some sort of centralized >> portage hash database. > > Use of ADSL is in no way a good argument for any kind of > remote filesystem.
My goal is a remote portage for distributing binary updates to my various machines in the field. NFS mounting /usr/portage is a means to that end. So far I haven't found a better way to do it. Perhaps I could lower the latency by only NFS mounting /usr/portage/distfiles and /usr/portage/packages instead of the entire /usr/portage and rsync'ing the rest of the portage tree to each remote machine... > Try using something like AFS or CODA > if you wish to do weird things like that. NFS is _very_ > bad for slow/unreliable links. > >> I think portage should try hard to avoid having to search >> the filesystem in a O(N) manner every time an emerge >> operation is run. > > It doesn't search the filesystem. It knows exactly what it's > looking for. Startup requires a listing of all valid packages > and then verification of the stat data on the files to ensure > the cache is current and valid. > >> What is portage doing during that 35 minute >> `emerge --update --deep --pretend world`? >> Please tell me that it isn't reading each individual ebuild > > It's causing disk seeks. A consequence of your NFS setup is > a _very_ high latency per seek. With several thousand ebuilds > this can amount to a very large number of seeks. Right. Changing my choice of network filesystem won't really help that much, will it? The fact that portage needs to perform those disk seeks every time the emerge command runs seems inappropriate to me. > After memory-caching of the portage tree, it takes a second > or two for my system to respond. The initial validations take > up to a couple minutes because of the seeking involved. Your > choice of FS can drastically affect this. I use reiser for > it's small-file benefits. > > A pure-cache 'frozen tree' speedup is on my mind for later, > but it won't be that soon. It will still be dramatically > slower of your system because of your setup. But if it eliminates all of those disk seeks then it should be dramatically faster than the current setup when used over NFS and when used locally. -- Jesse Guardiani, Systems Administrator WingNET Internet Services, P.O. Box 2605 // Cleveland, TN 37320-2605 423-559-LINK (v) 423-559-5145 (f) http://www.wingnet.net -- [email protected] mailing list
