(Illustration by Gaich Muramatsu)
On 22 May 2000, at 16:16, Jan Harkes wrote: > NFS/Samba have a completely different model, they are block based. If > you read a very large uncached file in Coda, you have to wait until it has > been fetched completely. Once it is in the cache, read/write access is > pretty much similar to local disk speed. So if you are doing several sweeps > through a 500MB file, the others will really suck. > > On the other hand, if you read that file just once and never ever look at > it again (i.e. unpacking a tarball), filesystems like NFS are more likely > to be useful. I think it would be an interesting research project to support "trickle read ahead". Where portions of the file that are requested are returned (if cached), while the file is read from the server by the cache manager in the background. For small files, this probably won't buy much, but for large files it might be useful, especially if the cache manager can request file sections from the server, while trickling in the rest of the file. > We always send back a file that has been opened for writing, any sane > application (except for Win95 ones) only opens for reading if they Is this true even if no write operation has taken place on the file? Perhaps the application opened the file for the possibility of writing, but in the end did not write() to the file at all. Do you send the file back to the server then? Brad Clements, bkc_at_murkworks.com (315)268-1000 http://www.murkworks.com (315)268-9812 Fax netmeeting: ils://ils.murkworks.com AOL-IM: BKClementsReceived on 2000-05-23 09:34:45