Coda File System

Re: Volume write problem

From: Jan Harkes <jaharkes_at_cs.cmu.edu>
Date: Tue, 20 Mar 2007 19:23:59 -0400
On Wed, Mar 21, 2007 at 12:49:10AM +0100, Davor Ocelic wrote:
> Could you shed some light on this ?
> 
> I create a volume and mkmount it, but any write results in "Connection timed out".
> # volutil create /vicepa user.doc
> # bldvldb.sh

Ehh, you created a replica, not a replicated volume. The client will
never write to an individual volume replica because if it is part of a
replicated group every update would result in conflicts.

A replicated volume consists of one or more replicas that are each
created by volutil create their location information is stored in the
VLDB (which is constructed by bldvldb.sh). The replicated volume itself
doesn't have a location as such, but a higher level description in
/vice/db/VRList (which the server uses to build the VRDB, or volume
replication database)

The createvol_rep script does everything necessary to create both the
individual replicas as well as the replicated volume.

> # cfs lv doc/
>   Status of volume 01000004 (16777220) named "user.doc"
>   Offline message is ""
>   Volume type is ReadWrite

Although strange, this is in fact a read/write replica, there is also a
read-only replica which is used for backup volumes. The backup volume
can never be part of a replication group as it is a fixed snapshot in
time. There used to be a third type which was the AFS2 non-replicated
read/write volume.

Jan
Received on 2007-03-20 19:25:36