On 11/5/2018 1:05 PM, Chris Miller wrote:
Hi Folks,
I have four servers, henceforth AMANDA clients, that I need to backup
and a lot of NAS space available. I'd like to configure AMANDA to treat
each of the four AMANDA clients as if it were the only client, meaning
each client should have it's own configuration which includes location
for backup storage. I have a 3 TB staging disk on the AMANDA server. I
have reasons for the individual treatment of clients that include
off-site storage requirements and differing data sensitivity, so the
simple solution is to be able to configure AMANDA to treat each client
as a single case, so I can provide for proper security and custody of
the backups. Can this be done?
Yes, just create a separate configuration for each client on the server
(that is, a separate amanda.conf and disklist for each client, with each
pair being in it's own sub-folder of your main amanda configuration
directory). This is actually a pretty common practice a lot of places
(for example, the company I work for has 3 separate configurations that
run at different times overnight and have slightly different parameters
for the actual backups). The only caveat is that you have to explicitly
run dumps for each configuration, but that's really not that hard.
Please refer to the small table below. I have some basic questions, but
the volume of documentation is difficult to grasp all at once, so please
forgive what might seem like trivial questions; they are not yet trivial
to me.
Using 10.1.1.10 from the table below as an example:
1. I think I define the length of my tapes to be the maximum for a
given client backup, which is the size of a level 0 dump, which is
135 GB for the example of 10.1.1.10. Since I want to configure
AMANDA to treat each client as an individual and not part of a
collection of backup tasks, I assume AMANDA will use one vtape per
client per night. Can this be done? How do I qualify configuration
settings per client?
The main part of this should be answered by my comment above (if you
have separate configurations, it's trivial to specify different settings
for each client).
That said, you probably want the vtape size to be _larger_ than your
current theoretical max backup size, because it's very hard to change
the vtape 'size' after the fact, and if you run out of space the whole
backup may fail. Keep in mind that vtapes only take up whatever space
is necessary for the data being stored on them (plus a bit extra for the
virtual label), so you can set this to an arbitrarily large value. As
an example, the vtape configuration where I work specifies 2TB vtapes,
because that's an amount I know for certain we will never hit in one
run, even if everything is a level 0 backup.
2. I have planned for one level 0 and five level 1 backups per week. Do
I call this "a cycle"? I think I need 185 GB storage per "cycle" and
this tells me how many "cycles", in this case, weeks, I can store
before I have to re-use tapes. Does this mean I can plan on a 43
cycle (week) retention of my backups? Will AMANDA append to tapes,
meaning can I put a full week on one vtape?This doesn't _quite_ line up with what Amanda calls a cycle, see my
comments on your next question for more info on that. Also, as
mentioned above, assume you will need more space than you calculated,
failed backups are a pain to deal with.
As far as taping, Amanda _never_ appends to a tape, it only ever
rewrites whole tapes. While it's technically possible to get Amanda to
pack all the data it can onto one tape across multiple runs, it's
generally only a good idea to do this if you need to store backups on a
very limited number of physical tapes because:
* It means that some of your backup data may sit around on the Amanda
server for an extended period of time before being taped (if you're
doing a full week's worth of backups on one tape, that level zero backup
won't get taped until the end of the week).
* Amanda rewrites whole tapes. This means you will lose all backups on
a tape when it gets reused.
Because you don't have any wasted storage space using vtapes, it's
better to just plan on one vtape per run, specify a number appropriate
for your retention requirements (plus a few extra to allow recovery from
errors), and then just let Amanda run. Such a configuration is more
reliable and significantly more predictable.
As another concrete example from the configuration where I work: We do
4 week cycles (so we have at least one level zero backup every 28 days
for each disk list entry), do daily backups, and retain backups for 16
weeks. For our vtape configuration, this translates to requiring 112
tapes for all the current backups. We need to be able to access the
oldest backups during the current cycle, so we have an additional
cycle's worth of tapes as well (bringing the total up to 130). We also
need to guarantee that if an error or two happens, it won't violate that
retention requirement, so we added a couple of extra tapes as well,
giving us a total of 132. This gets specified using the `tapecycle`
parameter in the config.
3. AMANDA will give me at least one level 0 dump per week per client. I
think this means that my backup "cycle" is 7, but I'm not sure what
this is called of where I define it. This can be global, for now,
but I may have occasions where the "cycle" is different from 7.
Yes, your cycle would be 7 days. This is specified with the `dumpcycle`
parameter in the config. The other important one here is
`runspercycle`, which tells Amanda how many times it will _normally_ be
run during that dumpcycle (Amanda actually does handle things reasonably
well if you don't run backups exactly this many times in a cycle, as
long as it's not a very frequent occurrence).
Also, there will be one night a week, when AMANDA will not do a
backup, because I will be doing a disk image backup, so I need to
know how to turn off, say, Saturdays. (If there is a way to include
a disk-image backup in AMANDA discipline, I would be very interested
to read about it.)
Amanda doesn't issue the backups itself, you tell it to run them.
Usually, people do this using cron. So, excluding one day is trivial
(just don't tell Amanda to run a backup on that day).
So, somewhere I have to tell AMANDA "135 GB". "7", "185 GB" and "43",
and I have to do something similar for each of my four clients. What are
the names of the configuration settings, which have the values "135 GB",
"7", "185 GB" and "43", and where do I put them so that they are
qualified per client?
10.1.1.10 10.1.1.11 10.1.1.12 10.1.1.13
Level 0 (GB) /*135*/ 135 40 40
Level 1 (GB) 10 10 5 5
Demand (0) 135 135 40 40
Demand (1) 50 50 25 25
Cycle? Total /*185*/ 185 65 65
NAS (TB)
/nas0/d0 /nas0/d1 /nas1/d0 /nas1/d1
8 6 4 4
Cycles /*43*/ 32 62 62
