On 12/7/05, Denis Croombs denis@croombs.org wrote:
On 12/6/05, Jonathan Darton jdarton@ibigroup.com wrote:
I want to build 2 servers (both running samba) to provide file storage to 2 offices (approx 100 miles apart, linked via DSL) but all data writen to 1 server must also be saved to the other server. Both servers would also allow users to access the data via a VPN thus allowing 1 office with a failed server to access the other server via the vpn and still see the data from both offices. I currently have 1 server working but we want to add the second office to the system. (Currently 1 office has 10 users and the second office has 1 user connected via VPN ) but the second office will have 20 within 12
months
and the first will have 35 soon ))
Has anyone done anything like this ?
I am currently synchronizing multiple office locations using a program called unison. Unison (http://www.cis.upenn.edu/~bcpierce/unison/) is a very well written program that can perform 2 way file synchronization. There are many configurable options with unison and I
recommend that you check it out.
In each office I have a PII350 128RAM Fedora or CentOS server running unison and the files are accessed via samba. I also configure samba to hide (veto) all of the temporary files used during synchronization. For redundancy I place a slave server with each master server that backs up all the user data / file system using rsync. This way if one of my $5 PII servers catches fire I can automatically switch over with no
downtime for the users.
The only downfall I have encountered is with Autocad files not properly reading the synchronized .dwl lock file and more than one user working on the same file. As a work around for this I have configured Unison to keep a backup of the last 20 versions of a file. This way I can always hit my backups to retreive lost data. As a side note, if anyone knows a work around for the stubborn autocad dwl lock
file let me know :))!
In any case my implementation has allowed me to synchronize file systems between 4 offices (3 in Canada, 1 in USA), using recycled hardware that was otherwise going to be donated/trashed.
Let me know if you have any further questions.
I'm about to do a Unison setup on two CentOS servers, so I'm thrilled to
see this response. I also work with Architects >>sometimes, so I'm interested to hear about the dwl lock file issue.
My one compound question: how are you invoking Unison? In batch mode, with
cron? How often? Wat other options did you
consider before settling on the scheme you use?
I see the project is no longer supported, do you have rpms for it ?
Thanks
It's not that it's no longer supported, really, just that the project that initiated it is not an officially-funded academic project. It has actually been updated since the termination of the project, it looks like.
I haven't installed it on CentOS yet but I got FC4 rpms from fedora extras (I just typed 'yum install unison' and it worked). I think it's in pretty common usage in RHEL too, so it can't be too hard to find for CentOS, right? (But let us know what you turn up :-)).