(Illustration by Gaich Muramatsu)
So if I want to load up directories from the server I must install the coda-debug-client on it? What I am trying to do is include some directories for a distributed project. I will try to load a client and see what happens when I try to copy something into it. Stephen On Tue, 10 Oct 2000, Jan Harkes wrote: > Hi Stephen, > > I hope you don't mind me CC'ing this message to codalist, because I've > received this question often, so I guess the answer deserves a larger > audience. > > Coda doesn't work like NFS, if you create a file somewhere /coda on the > client the data is stored in a logical volume on the servers that serve > the data for this volume. The metadata is kept in RVM, the contents of > the file are stored in a file in /vicepa. > > I'll try to explain by example, > > echo 1234 > /coda/usr/jaharkes/testfile > > Here at CMU, /coda/usr/jaharkes is the volume vmm:u.jaharkes, a triply > replicated volume stored on the servers verdi, mozart, and marais. > > These server actually handle many volumes (about 100 I believe). And > they all allocate a unique cache file for the data, > > verdi happens to pick /vicepa/00/00/01/FF, mozart uses /vicepa/00/01/00/FE, > etc. They also store in RVM data the information that the root directory > of vmm:u.jaharkes now has a new entry named testfile, and the file's > metadata such as size, mode, owner, creator, timestamps, a versionvector > and which `containerfile' in /vicepa holds the data for this file. > > Some of this metadata could have been stored as attributes on the > container-file, but we don't do this for several reasons. For instance, > I don't have an user account on the servers, so the owner would already > become difficult. Forcing timestamps is messy, and setting the mode > would potentially make files on the server visible to people who > shouldn't have access to them. Also, there is no alternative for the > VersionVector, which is probably the most critical information we have > about a file as it is used to check consistency between copies of the > file in different locations, server-server replication (resolution), and > client-cache validity (f.i. after a disconnection). > > So /vicepa/install.log might exist, but as the server doesn't know about > all the _important_ stuff, it is completely useless to the server and it > simply ignores the fact that it is there. Besides, we really don't want > to have the server scan a N-gig /vicepa tree to figure out whether > someone happened to have added a file there locally. > > To summarize, you can only put files in Coda through a client, and they > can only be (correctly) read back using a Coda client. > > Jan > >Received on 2000-10-12 06:55:55