Coda File System

Re: Need some info on coda server configuration

From: <>
Date: Fri, 4 Jan 2008 19:52:59 +0100
Hello Dhiraj,

On Fri, Jan 04, 2008 at 02:05:28PM +0530, wrote:
> I am new to coda. I have this task to create a large file server of around
> 400 GB for storing images (on an average of 300 KB) for research purpose.
> To achieve this I want to use Coda filesystem for this purpose. I have

While the expected data seems to fit Coda properties and limitations,
I am not sure whether you are sufficiently prepared to make the decision
to deploy Coda. Nevertheless, trying to answer your questions:

> 1.) Does coda client also shares its disk space to store data? I mean, I


> have to create a large file space of 400 GB using 4 terminals with 120 GB
> harddisk each. So do how many servers and clients do I need to create to
> have 400 GB space.

You need one or more servers with the total amount of at least 400GB
of storage. As you may have read on the wiki or otherwise, it is
best to avoid using servers as clients or vice versa.

> 2.) Also, I read some of the older threads, which says to create multiple
> servers to have large disk space. How do I create those? Are there any
> proper steps given somewhere in the documentation.

Somewhere (probably scattered across many places) in the list archive
or on the wiki.

> 3.) How can I relate rvm metadata size and disk space size? Now as I want
> a 100 GB disk space on terminal, what rvm configurations should I do to
> achieve this?

This has been discussed many times. Skipping this one. See below.

> 4.) Do I need to create 3 partitions on coda server or 2, i.e. one for rvm
> logs, one for rvm metadata and one for data files OR one for rvm logs and
> other for both rvm metadata and data files in single partition?

No, use files for rvm. More or less, there is no need to bother about extra
partitions. As for rvm, there is no efficiency gain from putting it on
partitions, rather a loss, at least on Linux.
For data, there is no longer a need for an extra partition either.

> 5.) During configurations of coda server, the script asks for a question
> What is the size of you data partition (or file)
> [22M, 44M, 90M, 130M, 200M, 315M]:
> which relates to some disk space as i understand. Now 315 M stands for
> some 8 GB space. Does that mean I can use at max only 8 GB of my disk
> space? What exactly does this mean?

I personally find this script confusing as well.

As for the answer, try searching for "rvm size calculation" or similar...
Roughly, rvm size corresponds to the number of objects on the server, not
to the _size_ of those. Ca 1G RVM should be enough for your ca 1M files.
If the files will be spread between several servers (note, this does not
happen automagically, and has nothing to do with replication), each server
will have a smaller number of objects to keep track of, hence may do with
a smaller RVM.

Best regards,
Received on 2008-01-04 13:54:43