Gunnarsson, Gunnar wrote:
Hi,
On the Amanada Wiki there is a note on Solaris:
Set ST_MODE_SEL_COMP in st.conf for your device and then use the
correct tape device variant (do not use "c" and "u" device)
How can I verify that it is being set - the driver is seen and
configured by the system.
I want to use the driver in a none compression mode.
# mt -f /dev/rmt/0n status
HP Ultrium LTO 3 tape drive:
sense key(0x0)= No Additional Sense residual= 0 retries= 0
file no= 2 block no= 0
The drive is sitting in a SL48 Tape library and the host is Solaris
Sparc runnint Solaris 10.
Sorry this is more of an os question but still I give it a try.
I'm not sure it is so much an OS question.
Anyway, on my Solaris 9 SPARC Amanda backup server, I do not have that
line in my st.conf. I have used both the internal DDS/3 tape drive and a
Sony LIB162A5 AIT5 tape library on this server. In /dev/rmt, I find all
the variants of both drives (e.g. /dev/rmt/0n, /dev/rmt/0cn, and so on,
also /dev/rmt/1n, etc.) My Solaris 10 SPARC Amanda backup server has a
similar st.conf and /dev/rmt collection.
I typically use 0n or 1n. When I originally set things up, I used
amtapetype to test the tape/drive. It will tell you whether you have
compression on. Note when you look at
http://wiki.zmanda.com/index.php/Hardware_compression, the piece at the
beginning titled "Resurfacing HW compression." If a tape has been
written to using compression in the past, the drive may automatically
switch to compression. You have to make sure such tapes are properly
erased and over written to work without compression.
I admit it is slightly blind. You can't "see" directly what the drive is
doing. But, you get comfortable with it over time by experience and
observed behavior. amtapetype takes a long time to run, but it will tell
you how the tape/drive behaves. Then you see how it works over time with
Amanda. You see your speed, throughput, total capacity, etc., and that
fits with what you would expect. If you see anomalies, then you have to
figure it out. There can also be other issues that can cause additional
confusion and difficulties. With LTO3 you have to make sure your system
components are tuned to be able to handle the throughput and speed. That
may just mean having adequately beefy hardware.
--
---------------
Chris Hoogendyk
-
O__ ---- Systems Administrator
c/ /'_ --- Biology & Geology Departments
(*) \(*) -- 140 Morrill Science Center
~~~~~~~~~~ - University of Massachusetts, Amherst
<[email protected]>
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Erdös 4
