--On Thursday, October 30, 2003 14:47:41 +0000 Neil Robinson <neilr AT
superbase.co DOT uk> wrote:
> I have been reading the documentation online plus the configuration files
> and searching Google for several days now. I am to the point where I
> basically understand what Amanda does. A few questions still lurk, however.
> I apologize if any of these questions seem obvious, but to me they are not.
>
> To start with, I am trying to get my head around the concept of a run. Is a
> run a single line in the disklist or is it the entire disklist?
A run is a single day's backup. It includes your entire disklist.
> The reason that I ask, is that I have to construct a backup strategy under
> Linux for an office that has the following configuration:
>
> Web, private news, mail server:
> Dual P3-1000
> Linux Soft RAID5 with 3 36GB drives plus 1 36GB drive for the OS
>
> File and tape server:
> Dual P3-1000
> Linux Soft RAID5 with 9 36GB drives (also the tape host) plus 1 36GB drive
> for the OS
> HP Surestore DDS-4 drive
>
> Eventually also backup of various Windows hosts, the Linux firewall, and the
> Linux DNS server.
>
> To start with I just want to get the file server backup working. The problem
> is understanding what to configure. I have a 280GB RAID that is currently
> running at around 160GB in use. From what I understand after reading the
> docs, Amanda won't split a run across tapes. So, how do I define the system
> to do a full dump? The daily incremental backups apparently will each always
> require a single tape (I doubt any daily will ever exceed the capacity of
> even a DDS-3 tape of which I also have around 20). I am merely wrestling
> with the concepts here. I assume that I would need to define a run as never
> exceeding the capacity of a tape. Does that mean a separate directory and
> amanda.conf for each area, or does this mean a different line in the
> disklist file? If just a different line, that's fine, but does that mean
> that multiple runs will be stored on one tape if they fit?
Yes, a single disklist entry must be able to fit on a single tape (although
someone is currently working on patches to get around that). If your disk
is larger than a tape you need to specify subdirectories in your disklist
that can fit. You can either list them idividualy or use includes and
excludes with wildcards to cover them all. Amanda will put as many disklist
entries as will fit on a tape (from the same daily run), but will not
append onto a previous day's run. Note you can't really run Amanda more
than once per day, it will get confused on the scheduling and restores
since much of it seems to only deal with month-day-year and not hours.
> Also, I would prefer to get an email if a tape needs changing (in advance
> and if in error), but am not 100% sure where that information goes (do I
> change chg-manual or do I modify something else that is read by chg-manual)?
Each amdump run sends an email saying what was backed up and how long
each part took (among other things). It says what tape(s) was used and
what tape(s) it will look for on the next run. You can (should?) also
run amcheck during the day, it will tell you if the correct tape is in
the drive (and put it there if you have a changer).
If you have plenty of holding disk space and no changer you might
prefer to not use chg-manual and lie about your tape length. I'm sure
someone will correct me if I'm wrong (I don't use chg-manual), but I
think with chg-manual and a small holdingdisk Amanda pauses the backups
while it waits for a new tape. If you run it overnight and don't change
tapes until the morning, part of your backups will be run after you
change the tape, and you may not want the load on your servers and network
during the day (plus your filesystems may be more active). If you say
your tape is much longer than it is, Amanda will hit EOT and continue
doing the backups to holdingdisk. You can then run amflush the next
morning after changing tapes without impacting any other servers.
>
> Sorry for all the questions but for someone whose previous tape backup
> experiences were primarily Windows-based (although I have used Arkeia on
> Linux), a lot of this is fairly impenetrable.
Have you read 'the chapter' from Unix Backup & Recovery'? A link to an
online version is on the Amanda web site, but the book is worth buying.
Frank
>
> Thanks in advance.
>
> Ciao, Neil
--
Frank Smith fsmith AT hoovers DOT com
Systems Administrator Voice: 512-374-4673
Hoover's Online Fax: 512-374-4501
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