hpr-knowledge-base/hpr_transcripts/hpr0030.txt

Episode: 30
Title: HPR0030: Network Backups
Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr0030/hpr0030.mp3
Transcribed: 2025-10-07 10:28:09

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Hello and welcome to another edition of Hacker Public Radio.
Today I'm your host, D.J. Dawesman, and today we're going to be talking about backups.
I'm going to kind of dive into a couple of different types of backups.
I'm going to cover a couple of different pieces of software for one type of backup.
I'm going to cover and talk about the hardware setup and then kind of go over some other
concepts and such.
First, the backups that I used to make early on of my systems were basically you power
the system down, you boot it off in floppy disk with Norton Ghost or Clonezilla or something,
and then you either burn it to a local CD or DVD or you can shoot it over the network
to your ghost cast server or whatever you're going to do with it.
That's nice.
That gets a full complete backup of your system.
However, the downside to that is it's pretty manual and your system has to be down for
this to happen.
Because of that, I don't think a lot of people do those often enough.
I know I don't.
What I really like and what I've come to really appreciate about what we use at work is
an online backup system that backs up stuff over the network and automatically tracks
incrementals and runs while the system's up, so your production system so I have to
be down.
I started looking around for an open source way to do this on my own systems at home.
What I came across were two different packages, one is called Amanda and that's been the
good old standby for, I don't know, 15, 20 years now, and basically it's called Amanda
for originally created by the University of Maryland, I believe, and basically it's
a loosening collection of different scripts and programs, all packaged together with
a server and basically it runs as a Damon and so when it runs, just every night, it
just gains your system for files that have changed and that's your incremental backup
because it shoots off files that have changed on each of your servers over to a central
storage backup system.
Of course, the server component on the backup system then saves automatically manages writing
all the backups to tape for you, typically with a larger installation you're going to have
a array of multiple tape drives and a tape library, a robot moving tapes in and out.
You can also do that, they can store, I don't know if Amanda does this yet, stores to local
storage pools on online hard drives basically, so you don't have to have the tape drives for
the backups, but Amanda has been the standby for people doing stuff like that and it mostly
is intended for working with Unix or Linux systems, Windows systems, I think there's kind
of a hack way to do that using SMB shares and so on, to get backups of your Windows systems
using Amanda, I really wanted something a little less clumsy and I finally stumbled
across another package called Backula and their slogan is, it comes by night and sucks the
vital essence from your computers and it's only, it came about in 2000, 2001 or so I think
and it's, all of a sudden it has some very strong development behind it and a surpassed
Amanda quite a bit by its features, capabilities and robustness I think, which is kind of
unfortunate for the Amanda folks, it's a good, Amanda's a good thing, but anyway this
is Backula product, it's basically all completely distributed so you can have like a single
tape drive on each, you know, of several different computers and you can have those act as
agents that receive, you know, you have a central backup server that kind of, you know,
pulls the strings and manages all the backups to these other systems that have the storage,
all your client systems back up to the main Backula server and you could also just have
a standalone Backula system if you have multiple tape drives hanging off this one system
or a tape library, so that's what it does.
Commercial products in the same area of course if you're familiar with TSM or Legato
network or ArcServe backup exec, these are all very, very expensive commercial products
that basically do what I just described network backups with your systems online, so anyway
I decided I wanted to do something like this on my own for my own systems because after
a while you get so many different laptops, computers running and stuff, you don't keep
good backups of them and so I also just happen to have an XABXB210 dual drive 10 cartridge
didn't tape auto-changer that I acquired and I still got to get some tape drives to put
into it but basically any 8 millimeter tape drive will work with this thing that will
be compatible with the robot, the gripper, it's pretty slick, I finally, I've had it for
a couple of years but when I decided I never actually hooked it up and actually I like
used it and so I sat down and basically to get an auto-changer to work with Linux, there's
a couple things you're going to have to do, obviously you've got to get your scuzzy card set up,
I was using a future domain PCI card which worked fine under Fedora Linux, Fedora 5 and it's
pretty old but I've got a system that I'd use that's Fedora 5 and for experimentation and stuff
and at work fine I could control the accessor but under sent OS 5 which is basically Red Hat
Enterprise Linux, I have not been able to get the thing to work and the driver keeps crashing
anytime I try to use it, I don't know if it's an application problem or driver problem on
kind of suspecting it's a driver problem at this point because sent OS didn't come with this
driver by default whereas Fedora did, I was able to get it to compile but anyway some problems I've
had, so basically how do you use an auto-changer with Linux? Of course you mod probe your scuzzy card,
most tape libraries use the scuzzy generic Linux device driver set and so that rides on top of
your above your scuzzy card stack and then also you're going to have to have a scuzzy tape or ST
driver for your tape drive and your scuzzy changer is going to be a scuzzy idea on your scuzzy bus,
your tape drives will be separate IDs also on the same bus so basically you can
cat slash proc slash scuzzy slash scuzzy and if your scuzzy drivers initialize properly you'll see
both the auto-changer and the scuzzy tape drive and from that point you're good to go to try
with the MTX command and you can check out the man page on that for flags and how to use it
obviously and you'll reference the scuzzy generic device. Once the SG module is initialized into
the kernel you'll have a couple of devices out in your dev file system and usually like you'll
have at least SG zero and SG one those will represent the auto-changer and the scuzzy tape even
though you won't access the tape with the scuzzy generic interface to it. You'll use your regular RRMT
or whatever little device you have that your OS provides for that. The thing about scuzzy generic
is basically just very low level scuzzy interface so it just lets commands throw data at the scuzzy
bus, throw commands and stuff and so that's how that's why auto-changers are typically accessed
with the scuzzy generic. So once you get those things working then the next layer the actually user
commands is going to be MTX and there's a couple different user space commands for accessing
your tape-changer but MTX is pretty much the good old standby that I think everyone uses Amanda
uses MTX in order to manipulate the auto-changer or backulate uses MTX and I think they can use some
other utilities too but MTX that's that's the good way to go and it'll do some verification you
can do some basic status information from your library. I've got a little script when I had it
working under Fedora I could have it just you know run the move the robot back and forth and move
tapes automatically just kind of an exercise so that was a lot of fun to see working. So like I
said you were talking describe some of the applications software that writes on top of it so so
anyway once you get these layers of things set up and you get your your applications software
up either Amanda or backulate or possibly something else then basically you should be able to have
nightly incremental backups of all your files. I for most part I you know I've got a lot of like
text notes that I have personal documentation that I write for myself. I've had a growing library
of like video and photo photos and stuff that need to be archived a little bit better than I
currently do. So that's that's some of the things that I intend to use with it. I currently
I'm having some problem. I haven't actually gotten backulate up and running yet but that's mostly
because I once I I switched mid-mid process to a new system I got a dedicated piece of hardware
just to run backulate on and unfortunately like I said I've been having some problems with sent
who has but once I can get those issues resolved and I'll go ahead and start working again with
backula and the thing with with Amanda and backula and the I mean these the trade-off of having
a very convenient nice backup server is it takes quite a bit of configuration and massaging
to get these things to work right. You've got you know exclude lists like there might be certain
directories on your system that you don't want backed up. I don't know things like obviously
you don't want it to mess with proc there's no reason for it to be touching anything under there
and other other file systems and such. So it's going to take some tuning there's going to be quite
a few concepts you're going to have to I get your your head wrapped around and backula try is
pretty hard to explain these concepts early on to help you make the right decisions to configure
the system what you need. Some of the Amanda documentation really seems to be kind of they're
switching from their older style of documentation to a wiki and it seems like there's a lot of stuff
it is just really in the middle of a transition right now. My apologies to the Amanda folks if
they've worked out all those issues since I've looked at it but it seems like they're unfortunately
they were kind of overtaken it seems like with the functionality and backula there but it so that's
basically a good robust backup system how you would use it how to set it up. I'll have some
notes on the hacker public radio for some of these different things I've talked about.
So anyway have a good day enjoy and I'll see you later.
Thank you for listening to hacker public radio. HPR is sponsored by caro.net so head on over to