Jon LaBadie wrote:
[snip]
> If go with amanda you definitely should do that GFS filesystem as
> multiple DLEs. If I got your data size correct, you have about
> 1 TB of GFS data plus 0.4 TB of misc OS data, about 1.4TB total.
This in the case I will decide to split the actual filesystem into more
than one, that means I will need to create multiple DLEs.
But if I stick with just one big GFS fs, I think I will have just one
DLE and then Amanda will take care to span the tar volume into multiple
tapes, when it receives an end-of-media message. Please correct me :-)
> With amanda's dynamic scheduling, and say daily runs with a dump
> cycle of 1 week (7 runs/week, full dump of everything each week),
> a perfect balance would have 1.4TB/7 or 200GB/day of full dumps.
> Plus some incremental data plus it is likely that some DLE will
> get more than one full dump during the week. But it sounds like
> things would fit onto a single LTO-3 tape, even without considering
> compression. Your daily dumps would probably be about 300GB.
As far of my knowledge this should be:
dumpcycle 1 week
runspercycle 7
tapecycle 10 tapes
10 tapes are for the 7 tapes rotated weekly plus 3 for the size of the
GFS filesystem and possible errors.
Note that the incremental backups of the local servers will be probably
very small (we are talking about a few MBs for each server - those are
mostly log files).
Due to the nature of the platform the data mainly changes in the SAN
(GFS space).
> Amanda schedules best when it has a goodly number of DLEs to balance.
> It is hard to balance 4 DLEs of 1TB, 100GB, 100Gb, 100GB. :)
> You probaly have about 15-20 file systems among your 4 or 5 clients
> (will the server also be a client) and if you setup 8-10 DLEs from
> your 1TB GFS system, you should be golden.
I'd rather go with 3 chunks each of 400GB (at least, the first two of
400GB and the third with the remaining). Or if this does not fit well
for Amanda, I can create multiple chunks of 200GB, but not less, since
this is the size of the virtual disks on the SAN, that I striped with
the volume manager.
Please bear with my curiosity (:-)): if I strictly need a BIG filesystem
to be backed up, will Amanda behave _so_ badly?
Now, what it mainly concerns me, are the off-site tapes.
Like you said probably the best way to go would be having two different
tape sets: 1 for incremental+fullweekly, and 1 for fullweekly to be
taken off-site.
While the first set (incremental+full) will be entirely managed by
Amanda, I'd like to schedule the off-site backup (off-site meant as the
tapes have to be taken off-site, please don't confuse) to be lasted not
over a specific day of the week.
In that day some guys in the data center will be pulling off the
off-site tapes and inserting new ones. The next week they will be
reinserting the previous tapes, etc. Basically we have two tape sets to
be rotated weekly.
What they definitely need to know is which tapes are to be pulled off.
All the tapes in the changer will have a bar code label. Can I instruct
Amanda to send an email with which tapes have been used for a determined
backup (the full weekly off-site, in this case) so that the people there
will have an idea of which tapes need to be substituted?
Last but not least.. I have a total amount of available cartridges of 25
LTO-3 Ultrium (400GB). As far as I know, approx 10 will be needed for
the "in-site" backup, while for the full I will need approx.. 3-4 tapes
* 2 = 8?
Then a total amount of 18 tapes should be sufficient. 14 to be put on
the changer and 4 for the full backup to be rotated during the week by
the people in the data center.
> Prescription for stress:
> 5 amanda installations, bed rest, and call us in the morning.
I'd love to have a doctor like you.. but you'd hate to have a patient
like me..
;-)
--
Fabio Corazza - Engineering
NewBay Software, Ltd.
Wilson House, Fenian Street, Dublin 2, Ireland
Phone: +353 1 634 5490 - e-mail: fabio AT newbay DOT com
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