[PLUG] (OT) Backup Software Suggestions (Mark Phillips)

[Brian P. Martin]

I also have used dirvish (dirvish.org) for years, both in my office and 
at my client sites.  Depending on circumstances, I use a variety of 
storage solutions:

- For small sites, I use a USB disk drive, which I automount when needed 
and dismount when it's idle.  Of course, you could do the mounts by 
hand, too.  I usually have 3 or more disks, which I rotate off-site on a 
regular basis.  Rotation means a fire doesn't destroy your machine *and* 
its only back-up.  It also gives you some coverage in case of a drive 
failure on your back-up drive.
- For larger sites, I use a full size hard drive or a collection of 
drives in hot-swap SATA enclosures.  I use the automounter the same, and 
rotate them out as needed.
- For sites that have multiple locations, I have two dirvish 
installations at different locations.  Each backs up the "other" site to 
local, RAID-ed hard disks, which just live there permanently.

I've done full system restores from Dirvish.  There are a few things 
Dirvish doesn't get on the back-ups, and most back-ups don't get these 
either.  These include:
- the boot sector
- partition layouts
- databases. Dirvish backs up database files, but they're probably not 
any good unless the database server was down at the time.  You can use 
the preclient setting in dirvish to shut the database down, or if it 
can't come down then use its native utilities to back it up to a flat 
file, and let dirvish capture that.

I have code that dumps a lot of key information about a system (like the 
partition layout) to the local disk on a weekly basis, and dirvish 
captures that.  That gives me the info I need to, say, rebuild a trashed 
partition layout on an otherwise sound disk.

Dirvish is a "pull" backup approach, in that it runs in one place but 
can pull data from multiple machines if that's of interest to you.

An alternative from a few years back is duplicity.  I'm not sure of the 
current state of it, so you'll have to see if it's still active, but I 
suspect it is.

Duplicity is a push solution, in that it runs on the machine that is to 
be backed up, and stores the data on a remote machine.  Duplicity is 
able to use cloud storage in addition to remote solutions. Push 
solutions are good when your storage is available to you, but you can't 
otherwise manage the remote machine (e.g. can't install your own 
software, set up cron jobs, etc.).  They are fine for small set-ups of 
just a machine or two, but don't scale well because you have to install 
them individually on each machine that needs back-ups.  You also have to 
monitor the job on each machine to make sure it's working.  Pull 
solutions like dirvish can handle an arbitrary number of machines in a 
single run, assuming  you have a large enough back-up window.

Good luck.  Back ups are worth the effort.  They've saved me many times.

                                     -B.

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Brian P. Martin, Chief Consultant
Martin Consulting Services, Inc.
Phone: 503-617-4500
E-mail: Brian at MartinConsulting.com