Coda File System

R: coda questions...

From: Andrea Cerrito <>
Date: Tue, 29 May 2001 21:37:09 +0200
> -----Messaggio originale-----
> Da: Jan Harkes []
> Inviato: martedi 29 maggio 2001 17.21
> A: Mourad De Clerck
> Cc:
> Oggetto: Re: coda questions...
> > * i've heard that coda doesn't scale so well - is this true?
> Scalability is relative. A Coda server can currently handle many
> clients, and lots of data, but not a lot of files, or many files per
> directory. The limitations that I've seen hit are around 150000-200000
> files for every 100MB of configured RVM. Because of 32-bit address space
> limitations it is not realistic to run a server with more than 1-2GB of
> RVM, in which case the server would also need at least the same amount
> of virtual memory (real + swap). Extending this, a Coda server would max
> out at around 2 million files. Other problems are likely to hit before
> this time, such as excessively long server-startup times. Directories
> tend to fill up with as few as 4000 names.

About scalability, I have few questions.
We have two coda servers (replicated) with a lot of space: from my tests I
noticed it's a preferrable solution a lot of servers (processes, I mean)
instead of just one.


Pentium XEON 500Mhz, 2Gb RAM, 88 Gb space
13 coda srv (1 main, used only for internal, 12 for services directories,
like /coda/apache, /coda/qmail, and so on)
each servers handle 6gb of space, with 30mb rvm.

It can be a good solution? In such this way, I can add other NIC to load the
traffic between IPS changing only where each coda src is bindind.

> > * is there a specific filesystem recommendation for use with coda?
> > (ext2, reiser, xfs)
> As far as Coda clients are concerned, ext2 has been used the most and
> works well. ReiserFS is not supported by anything but recent Linux
> kernels (2.4.4 and later). I haven't looked at XFS yet, so it could
> still have problems.

I'm running ext3 both client / server, if it can interest :).

And for my point of view, Coda is a stable fs, with a lot of features, and
it can be used in a production environment (with some limitation due to the
hard link not allowed).
Cordiali saluti / Best regards
Andrea Cerrito
Net.Admin @ Centro MultiMediale di Terni S.p.A.
P.zzale Bosco 3A
05100 Terni IT
Tel. +39 744 5441330
Fax. +39 744 5441372
Received on 2001-05-29 15:40:10