Thomas,
Not sure where to begin, so I will try to begin at the beginning.
Amanda is designed to run daily, for purposes of my site that
usually means 5 days per calendar week, since we don't have
staff to change tapes on the weekend and only some of our
tape drives are in jukeboxes/libraries.
Amanda is not normally run more than once/day, though it can,
separate discussion for another time.
Amanda wants to backup each of the DLEs, DiskList Entries, in
the disklist file at each run. As amanda gets the lay of the
land it begins to schedule the dump levels so as to try and
backup similar volumes of data in each run.
Amanda will dump level 0 _at least_ once every dumpcycle days.
For most configs at my site, dumpcycles is "weekly" meaning
I get at least one level zero of each file system each week.
We typically have a tapecycle, of 20 tapes. This gives me a
4 week tape rotation with at least 4 level 0 dumps and the
rest are at higher dump levels.
The tape savings, the, don't waste a lot of tape on static
files is handled for me by the dump levels as scheduled
by the amanda server. [Discusson how how it does that
withheld for another time, see 'estimate phase']
There is no longer any
- "select a system for fulls M and Thursday and
other systems T and Friday",
all of that static control is usually released to Amanda
and freeded by you. This sometimes takes takes a bit of
getting used to.
All of this takes place for a given amanda server (has amanda
work/spooling area and an output unit, tape drive or library
of some type) and a set of clients.
We have multiple amanda servers with non-overlapping client
pools but not because of scheduling. We have multiple amanda
servers because of 1) server/tape capacity 2) geographic location
3) political and/or funding domains 4) security requirements.
I have an amanda server that has little on it other than an OS
and samba shares, that system has 200+ gig worth of samba shares
but the nightly output to tape is less than 30 Gig per day.
Its a lot to take in, please feel free to ask additional questions.
Brian
On Thu, Oct 21, 2010 at 03:50:34PM -0400, Jon LaBadie wrote:
> On Wed, Oct 20, 2010 at 12:10:16PM +0200, Thomas Marko wrote:
> > Hi!
> >
> > I want to setup amanda to backup some important data, but I am afraid
> > that I do not understand correctly how amanda works inside. I am not
> > sure if I am doing right or in a best practice way.
> >
> > As the amount of data is very large (630GB), thus the backup time would
> > be very long (especially L0's) I divided the data into data which
> > changes fast and should be backed up daily (DailySet1) and data which is
> > very static and should be backed up weekly. The weekly data I also
> > divided into 4 parts (WeeklySet1-4) so that the runtime of the backup is
> > shorter.
>
> I'm not sure if it is best to make up 5 distinct Amanda configs, or just
> one config with customized DLEs and dumptypes. I'd probably try the
> latter first. I think it would make the best use of your storage media
> rather than targeting specific amounts for each config.
>
> Maybe others will add their views.
>
> There are a few things I will comment on below:
>
> >
> > The parameters for DailySet1 are:
> >
> > dumpcycle 4 weeks
> > runspercycle 28
> > tapecycle 30 tapes
> > runtapes 4
> >
> > tapelength 10 gbytes
> > tape_splitsize 1000 mbytes
>
> You are only asking for a single lvl 0 dump every 4 weeks. Dangerous
> in my view. The days the lvl 0 is done for Documente and WindowsHomes
> would take 2 and 4 tapes respectively. Some other days may also take
> multiple tapes. Your 30 tapes will be used before your dumpcycle is
> finished. And even if you add just a couple of tapes, it is likely
> that the next lvl 0 will overwrite the older one. If anything happens,
> (eg. network connection lost, system crash, disk errors, etc.)
> you will have no lvl 0 remaining.
>
> You don't seem to be using a holding disk so you will be writing
> directly to the vtapes. That increases the likelyhood of trashing
> something on problems. It also eliminates dumping multiple DLEs
> in parallel. Rather one after the next will have to run.
>
> >
> > The parameters for the WeeklySet1-4 are:
> >
> > dumpcycle 4 weeks
> > runspercycle 4
> > tapecycle 6 tapes
> > runtapes 4
> >
> > tapelength 50 gbytes
> > tape_splitsize 10000 mbytes
> >
>
> Mostly the same comments about the number of tapes.
>
> Even if you want Daily and Weekly to be different configs, rather
> than DLEs of one config, consider putting the DLEs from the four
> weekly configs into a single config. First benefit you get is
> 24 tapes of the current size. The dumptype could be set to
> "strategy nofull" (or is it "strategy incronly" ?) and use
> amadmin "force" commands (from cron) to specify when to do fulls.
>
> > I am using Amanda 2.6.1p1-2 on a Ubuntu Lucid distro.
>
> Seriously consider moving to the 3.x versions.
>
> >
> > The largest DLE in the daily set is about 30G, that's the reason why I
> > used 10G tapes and let amanda run 4 tapes. I split the tapes into 1G
> > chunks to fill the tapes better.
> >
> > The largest DLE in the weekly sets is about 180GB, that's the reason why
> > I used 50G tapes and let amanda run 4 tapes. I split the tapes into 10G
> > chunks to fill the tapes better.
> >
> > I chose to use 30 tapes * 10GB + (6 tapes * 50GB) * 4 to fit the disk
> > space of 1,8T.
> >
> > The keep time of the data does not need to be very long (I do not need
> > many old versions of specific data). It should be enough to have 2 week
> > old versions of the backed up data (two runs in WeeklySets and 14 runs
> > in DailySet).
>
> > In my understanding I would need at least L0 dumps every two weeks. To
> > keep the amount of data small and the time to backup short the amount of
> > incrementals should be as large as possible.
>
> If you want lvl 0's every two weeks, then should to set the dumpcycle
> to two weeks and the runspercycle appropriately.
>
> >
> > How do I accomplish all my needs with the resources I have?
> > Is the way I am thinking completely nonsense?
> > Are there any best practice rules tipps or recommendations for me?
> >
> > Beyond I attach my configurations. I removed some default lines, not
> > needed dumptypes and disktypes and the comments for better readability.
> > Also I attach the disklists for all my sets.
> >
> > I hope that anyone can help me :-)
> >
> > Any comments are appreciated. Thanks in advance!
>
> If you run your backups on the "ragged edge" of sufficient storage,
> I would say your (i.e. your mgmt) do not value highly the data
> that is being backed up. An extra pair of 1-2TB drives would cost
> about $125-$250. Isn't extra safety of your data worth it?
>
> jl
> --
> Jon H. LaBadie [email protected]
> JG Computing
> 12027 Creekbend Drive (703) 787-0884
> Reston, VA 20194 (703) 787-0922 (fax)
---
Brian R Cuttler [email protected]
Computer Systems Support (v) 518 486-1697
Wadsworth Center (f) 518 473-6384
NYS Department of Health Help Desk 518 473-0773
IMPORTANT NOTICE: This e-mail and any attachments may contain
confidential or sensitive information which is, or may be, legally
privileged or otherwise protected by law from further disclosure. It
is intended only for the addressee. If you received this in error or
from someone who was not authorized to send it to you, please do not
distribute, copy or use it or any attachments. Please notify the
sender immediately by reply e-mail and delete this from your
system. Thank you for your cooperation.
