Karl R. Balsmeier wrote:
> Looking to cluster an FTP server. Right now we do a mix of stuff where
> we use a few separate servers linked through various hacks, that
> utilizes VSFTPd heavily for hundreds of television station news
> websites, where, of course, the current weather maps get uploaded from
> everywhere, all day, from NOAA and the like.
> I'd like to move from the current setup to something that's more HA
> oriented, -is GFS and option in Centos and is it viable to make an FTP
> server setup like this?
>
> (please no responses about SFTP, I use that too on other servers and
> yes, prefer it even if it slows things down). Hardware is not an issue,
> just curious about what some of you sage folk might have experimented
> with, and possibly have put into production. A google search turned up
> relatively empty, so hopefully this isn't one of those questions that
> gets a collective "huh?".
Even mediocre server-quality hardware generally runs for years these
days without problems so I haven't been convinced that something like an
ftp server can be improved by adding complicated redundancy or failover
schemes. They aren't going to help if an operator or some software
error does the equivalent of 'rm -rf /' anyway, which is at least as
likely as a hardware failure. I usually do software RAID1 on drives
with swappable carriers so they can tolerate a disk failure, and I keep
a spare chassis (per several servers) so I can pop the drives over
without much downtime if there is a motherboard/power issue. For the
things that do need redundancy, like a farm of web servers, I'll rsync
the files that need to be updated (like weather maps from the ftp
server...) so each gets its own copy.
> Essentially am just trying to get away from the many separate machines I
> use now where I have to clone entries from /etc/passwd and /etc/shadow
> all over the place.
I've never understood why a multi-master LDAP server with posix and
samba accounts has not been included in linux distributions from the
start. In my opinion that's been the real missing piece for business
acceptance of Linux. For some machines I turn on SMB authentication and
point it at a Windows box, but I always feel a little queasy while doing
that - and I still have to maintain the accounts, just not the passwords.
> Bonus: I have an ISCSI NAS device/promiseraid, so
> perhaps there's an option there instead of doing GFS I could grab a
> slice of space that way and just have one server with a huge amount of
> space? It doesn't answer point of failure totally, but...
Sometimes I keep 'warm spares' around in the form of prebuilt disks or
VMware images of working servers but it always takes some time to update
them with current data if they have to go into service. It could be
really handy to keep fresh data with rsync or something like drdb or a
raid mirror to an iscsi partition that one of these could attach and use
directly as needed.
--
Les Mikesell
lesmikesell at gmail.com