On Tuesday 27 August 2002 00:12, Galen Johnson wrote:
>Thanks for the input, Gene. Jon LaBadie has been corresponding
> offlist with many useful suggestions plus some helpful info. It
> seems that I definitely have hardware compression by default and
> have to find out how to disable that on my Slackware system, then
> let amanda do the compression itself. I'll post a summary
> when/if I get this working like I think it should just so that
> there is something in the archives for posterity (a la the
> sunmanagers list)
>
>=G=
>
>Gene Heskett wrote:
>>On Monday 26 August 2002 15:47, Galen Johnson wrote:
>>>Hi folks,
>>>
>>> I realize that amanda may be overkill for what I want but...has
>>>anyone setup amanda to use a Sony DDS2 tape device? I'm
>>>currently running the 'tapetype -f /dev/nst0 -e 8g' command to
>>>verify the tape itself. Of course, the 8g is compressed instead
>>>of normal. Has anyone already configured a tapetype in the
>>>config file to address the DDS2 tapes? I'm in the initial
>>> stages of setting this up so any advice would be greatly
>>> appreciated. (After I play around with my system I get to try
>>> it with a production system that uses an Exabyte EZ17 Mammoth
>>> autoloader in place of a veritas system that wouldn't handle
>>> the changer).
>>>
>>>=G=
>>
>>First, you may as well ctl-c the tapetype run as the info you get
>>when the drives compression is on is pretty bogus. The tapetype
>>program uses /dev/urandom as the data source, and as its random,
>>its not normally compressable, and may in fact expand some.
>>
>>Second, heres mine.
>>--------------------------
>>define tapetype DDS2 {
>> comment "just produced by tapetype program"
>> length 3780 mbytes
>># lbl-templ "/usr/local/etc/amanda/DailySet1/DDS2.ps"
>> filemark 0 kbytes
>> speed 380 kps
>>}
>>----------------------------
>>
>>Note that by using one of amanda's dumptypes that uses
>> compression, the compression ratio can be quite a bit higher
>> than the drive can do. I have half a dozen directories that
>> regularly exceed 100% in < 20% out.
I forgot to add that when the drives compression is on, amanda
doesn't have a good idea what the tape can hold. With it off,
amanda can intelligently adjust backup levels to average the amount
backed up each night, and attempt to keep inside of one tape a
night. It does that rather nicely here with a DDS2 tape changer,
and theres about 30 gigs of data to backup every week on a 7 days a
week cycle.
Now, once you get it going by using a compressing dumptype, inspect
the email you get from amanda, and adjust the disklist to use a
non-compressed format for any entry that shows expansion, more than
100% in the compressed column. A directory full of rpms and
tar.bz2's or tar.gz's will almost certainly expand in the
compressor stage, so you might as well just feed them straight to
the tape.
--
Cheers, Gene
AMD K6-III@500mhz 320M
Athlon1600XP@1400mhz 512M
99.13% setiathome rank, not too shabby for a WV hillbilly
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