Coda File System

Re: practical limitations for file size/number in Coda

From: Stephen J. Turnbull <>
Date: Sat, 01 Nov 2003 21:34:13 +0900
I'll take a quick hack at an overview, but authoritative answers will
come from somebody else (probably Jan Harkes; Ivan Popov is a
reliable experienced user and there are a couple others whose names I
forget, mea culpa).

>>>>> "Michael" == Michael James <> writes:

    Michael> What are the limits of Coda?

Rather complicated as compared to normal file systems, or even
familiar network file systems.  Coda limits come in two flavors,
RVM-related and cache-related.  Basically, file size and things like
that are limited to the size of the client cache.  File system
complexity (for want of a better word) is limited by the way things
are organized in RVM.  All meta data (ie, the entire directory
hierarchy for all volumes, and some file attributes and maybe ACLs)
must fit into RVM.  Also, there are some arbitrary limits like the
number of files per directory.

    Michael> What is the biggest file it can handle?

The size of the local cache, or the maximum int (unsigned int?).  I
don't think Coda groks large files yet.

    Michael> What is the biggest Coda volume?

I don't think there's a limit in bytes.

    Michael> What other limits might bite a user with lots of big files??

The main one I would think of in your application is that you do not
get online access to the file.  If the file is not in the cache
already, the program will block in the open call until the file is in
cache.  This is different from other networked file systems where you
have access to any data that has already been transferred.

On the other hand, you probably will never run into any of the
RVM-based limits: 400GB/2GB = only 200 files.

    Michael> I looked and couldn't find answers to these basic
    Michael> questions on the Coda site.

Documentation has been an issue for while.  Really there isn't much
alternative for this kind of question to browsing the mailing list
archives, or asking on the mailing list.

Institute of Policy and Planning Sciences
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Received on 2003-11-01 07:44:29