Xref: utzoo comp.unix.ultrix:6312 comp.protocols.nfs:1812 Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!helios!bcm!convex!thurlow From: thurlow@convex.com (Robert Thurlow) Newsgroups: comp.unix.ultrix,comp.protocols.nfs Subject: Re: Ultrix 4.1 NFS bug Message-ID: Date: 21 Feb 91 21:48:39 GMT References: <1991Feb21.172023.19905@cimage.com> Sender: usenet@convex.com (news access account) Organization: Convex Computer Corporation, Richardson, Tx. Lines: 29 Nntp-Posting-Host: dhostwo.convex.com In <1991Feb21.172023.19905@cimage.com> brian@cimage.com (Brian Kelley) writes: >Ultrix NFS seems to cache inodes (at least that's what I would call it). NFS clients may indeed cache the meta-data associated with the file (a.k.a. the attributes) for a period of time. (It doesn't have, need or want all of the inode data, but does have stuff like the mod time, size, permission bits, etc.) This time period is normally adjustable on a per-mounted-fs basis, and can be tuned to be different for file and directory objects if desired, and may be turned off (which might even work now in 4.1 - it didn't in SunOS 4.0). Now, that won't help you, because you're outsmarting the algorithm. Read on. After this 'cache attributes' time limit has passed, many operations over NFS will fetch a new set of attributes. If the new attributes carry a newer modification time, the attributes will be installed and the cached bages in the buffer cache will be burned. Your test case sets the server attributes _older_ than the client version, so the client will not flush attributes at all. If you do a normal 'touch' on the server, you should see the client pick up the change within a few seconds, depending on your mount options. Since most makefiles don't hammer a phony date into the mod time, this works reasonably well, but it is something to remember. If it's a real problem, you should be able to bypass the attribute cache with a mount option. Rob T -- Rob Thurlow, thurlow@convex.com An employee and not a spokesman for Convex Computer Corp., Dallas, TX Brought to you by Super Global Mega Corp .com