>> ADIC Scalar 100 - 4x Quantum DLT7000 Drives
>> - the picker has a barcode scanner
>> 120 DLT IV's
>>...
>> dumpcycle 4 weeks # the number of days in the normal dump cycle
>
>Are you sure you want this? It means that each disklist entry (DLE) will only
>be gauranteed a full backup every 4 weeks. IT also means that if you need to
>restore it you have to use up to 20 tapes to do it (since your running 5 days/
>week)
We run configs here with a four week cycle due to the quantity of data
backed up per night. Simple math of bytes dumped divided by drive
bytes/second. Something had to give, so it was the dumpcycle which
has the effect of lowering the daily dump amount (and thus the time to
dump it).
DLT7000 drives are ~5 MBytes/s, so in a typical 8 hour backup window you
can do at most ~140 GBytes (~4 tapes at 35 GBytes/tape). Those estimates
are high, however, due overhead in various places.
Geoff may have to use a larger dumpcycle than "normal". However, I
agree with Frank that it should probably start smaller and only crank
up if necessary.
Also, the maximum number of tapes you will ever have to use for a restore
is 10. Amanda never runs an incremental level higher than 9, so a full
dump plus 9 incrementals is the worst case.
Not that 10 is much more pleasant than 20 :-).
>> use 290 Mb # how much space can we use on it
>
>If your DLEs are larger than this number then it won't do you any good ...
I agree that 290 MBytes seems very small. The more you can give Amanda,
the better it can parallelize/buffer the backup process.
On the other hand, if this is all you have, it's better than nothing.
Also, if this is a file system dedicated to the Amanda holding disk, you
might try setting the value to something like "-10 MBytes", which tells
Amanda it can use all the space currently available minus 10 MBytes
(for slop). That way, if the amount available changes (you grow or
shrink the partition, some dumps are left over from a previous run,
etc), you don't have to change the holdingdisk setting in amanda.conf.
>>Geoff
>Frank
John R. Jackson, Technical Software Specialist, ITaP/RCS, jrj AT purdue DOT edu
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