Email delivery (sendmail->procmail->$HOME/mbox) with fallback

[Tim Alberts]

John Summerfield wrote:
>
> Are you serious? You are running mission-critical applications on the 
> second least reliable software offering from the RHL family?
I'm guessing you don't work in advertising for Red Hat, Fedora, or Linux 
in general?


>
> Use good hardware, good software (RHEL or a clone), IMAP and not POP3, 
> and use one of the reliable RAID (1, 4 or 5) choices for your mail 
> (and other critical data) storage.
Been using POP3 forever with no problems (except some Mac problems with 
Dovecot).  Have RAID1 software setup for years as well.  Keep getting 
drive failures and looking back into hardware RAID with high quality 
equipment (as mentioned before).

>
> Even if a dodgy Fedora software update doesn't get you, you still have 
> to contend with frequent upgrades of the software.
Yes, I've dealt with 'dodgy' updates and config files being lost by auto 
updates, and bug fixes that mess things up that worked fine.  For the 
price, it has been acceptable (at least to the people in charge of the 
purse strings).

>
> Note that RAID _can_ include a network block device (nbd or enhanced 
> nbd drivers), and drbd also provided RAID1 over a network, and is 
> tolerant of breaks in connectivity.
>
> note that LVM can provide hot backups.


>
> One trick I've hard of is to define a firewire drive (presumably USB 
> or other hotplug drive) would do as part of a mirror pair. Backup goes 
> something like this:
> Plug it in
> Resync.
> Detach (I don't recall the fine details here)
> Unplug.
Used removable drive trays for rsync backups without the RAID. Now we 
got backup systems that are rsync backed up and ready to run in 
failures.  However, any email that was delivered between the last rsync 
and the failure gets lost temporarily or permanently.  Hence my idea for 
NFS mount to quality RAID1

>
> Google for terms such as "reliable linux" "high availability linux" 
> "linux cluster" etc for more details.
Google'd and Yahoo'd...seen hundreds of ideas mostly based on 
heartbeat.  In fact I most recently was looking into Red Hat's Global 
File System and clustering:

http://www.redhat.com/gfs/
http://www.redhat.com/cluster_suite/

Trying to figure out how Red Hat is accomplishing these things with open 
source, or if they are adding their own proprietary background stuff.



All-in-all, fun discussion, but completely off topic from my original 
post and still doesn't answer my question.