Re: Blocksizes and tapebufs

Ian Turner schrieb:
> On Friday 18 January 2008 13:11:35 Stefan G. Weichinger wrote:
>> Any suggestion for the new parameter device_output_buffer_size,
>> especially with the DLT8000?
> 
> There are a lot of factors involved in the choice of this parameter (speed 
> and 
> latency of CPU, memory, system bus, holding disk, scsi bus, tape device, and 
> more), so I can't give you a number. But I can say:
> - Bigger numbers will take up more memory, but never make things slower 
> (unless you run out of RAM!)
> - The default of 1280kb should be adequate unless there is a big difference 
> in 
> speed between the holding disk and tape device.

First steps with the beta of 2.6.0 (gentoo-ebuild available here ...) :

-- Tried the new naming convention "tape:/dev/nst0a", did not work:

amanda@ng ~ $ amlabel -f dds OLD-09
labeling tape in slot 6 (tape:/dev/nst0a):
Reading label...
File /dev/nst0a is not a tape device.
amlabel: 1200741201.958550: Could not open device tape:/dev/nst0a.

-- Edited it back to the old value:

amanda@ng ~ $ cd /etc/amanda/dds/
amanda@ng /etc/amanda/dds $ vi amanda.conf
amanda@ng /etc/amanda/dds $ amlabel -f dds OLD-09
labeling tape in slot 6 (/dev/nst0a):
Reading label...
"/dev/nst0a" uses deprecated device naming convention;
using "tape:/dev/nst0a" instead.
Error reading 32768 bytes from /dev/nst0a: Cannot allocate memory
Error reading Amanda header.
Found an unlabeled tape.
Writing label OLD-09..
Checking label...
Success!

-- Does that mean that I now use the old taper-code again?


-- I had blocksize 2048k in my tapetype before and all the tapes are now
labeled with that blocksize. I configured amanda-2.6.0 with

--withmaxblocksize=4192

to give me room to test, but it seems as if either it doesn't accept
this anymore or if I somehow screwed up the compile and ended up with
the old binaries due to some ccache or something. Gotta look that up.


amanda@ng /etc/amanda/dds $ amcheck -s dds
Amanda Tape Server Host Check
-----------------------------
Holding disk /amhold/dds: 61412 mB disk space available, using 61312 mB
"/dev/nst0a" uses deprecated device naming convention;
using "tape:/dev/nst0a" instead.
slot 6:read label `OLD-09', date `X'.
"/dev/nst0a" uses deprecated device naming convention;
using "tape:/dev/nst0a" instead.
NOTE: skipping tape-writable test
Tape OLD-09 label ok
Server check took 20.252 seconds

(brought to you by Amanda 2.6.0b1-20080117)


--


I will now relabel some tapes, using the default 32k blocksize.
Let's see if it gets faster.

And I will research that maxblocksize-issue.

Greets,
Stefan