Need larger dump tape length/block size for 2GB 4mm DAT

Need larger dump tape length/block size for 2GB 4mm DAT

Post by Julie Schneid » Fri, 03 Jan 1997 04:00:00



Hi all,

I'm using FreeBSD 2.0  with dump and an Archive Python 2330 2 GB 4mm
DAT/Adaptec 2940UW. I'm backing up /, /var and /usr with 3 separate
dump commands.
/ and /var backup just fine, but /usr wants 3.5 tapes, even though
it's taking up just 3.5 MB.

Here's the command I'm using:

dump 0udsf 61000 295 /dev/nrst0 /dev/rwd0s1f

Here are the messages I'm getting:

Dump: estimated 297737 tape blocks on 3.25 tapes
Dump: change volumes: mount volume #2
Dump: fopen on /dev/tty fails: Device not configured

Is there a longer tape length/larger block size I could be using to
fit this all on one tape? Any suggestions appreciated. Thanks.

Julie Schneider
Foss Maritime

 
 
 

Need larger dump tape length/block size for 2GB 4mm DAT

Post by J Wuns » Fri, 03 Jan 1997 04:00:00



> Here's the command I'm using:

> dump 0udsf 61000 295 /dev/nrst0 /dev/rwd0s1f

> Here are the messages I'm getting:

> Dump: estimated 297737 tape blocks on 3.25 tapes

dump 0uBbf 2000000 32 /dev/nrst0 /dev/rwd0s1f

This will allow for 2000000 kilobytes of data, and use 32 KB per tape
block (which is much more efficient for DAT than the default of 512
bytes only).

I think it's also safe to make this number even larger; dump will
request a new tape if it reached the end of medium.

--
cheers, J"org


Never trust an operating system you don't have sources for. ;-)

 
 
 

Need larger dump tape length/block size for 2GB 4mm DAT

Post by Andreas Kle » Sat, 04 Jan 1997 04:00:00


[Posted and mailed]



Quote:> dump 0udsf 61000 295 /dev/nrst0 /dev/rwd0s1f

             ^^^^^ ^^^
Might be to little.

Look here, what I use

#! /bin/sh

PATH=/sbin:/usr/sbin:/bin:/usr/bin:/usr/local/bin
export PATH

#Filesystem  1K-blocks     Used    Avail Capacity iused   ifree  %iused  Mou. on
#/dev/sd0a       31775    13276    15957    45%     997    6681    13%   /
#/dev/sd0s3e     63567    37149    21333    64%     771   14587     5%   /www
#/dev/sd0s3f    127151    87752    29227    75%     970   29748     3%   /var
#/dev/sd0s3g    765058   500994   202860    71%   66171  125827    34%   /usr
#/dev/sd1s1e    193855   104777    73570    59%   39613   14145    74%   /news
#/dev/sd1s1f   1790627  1568729    78648    95%  111083  326675    25%   /local

TAPE=/dev/rst0
NTAPE=/dev/nrst0

DUMP="dump 0uBbf 5000000 32 $NTAPE"

#DUMP="dump 0uBbf 5000000 32 -"
#TEAM="team 512k 4 > $NTAPE"

echo -n "mkdump:: rewinding tape"
mt -f $TAPE rewind && echo " done."
#echo -n "mkdump:: retension tape"
#mt -f $TAPE retension && echo " done."
#echo -n "mkdump:: erasing tape"
#mt -f $TAPE erase && echo " done."

$DUMP /dev/rsd0a        # | eval $TEAM
$DUMP /dev/rsd0s3e      # | eval $TEAM
$DUMP /dev/rsd0s3f      # | eval $TEAM
$DUMP /dev/rsd0s3g      # | eval $TEAM
$DUMP /dev/rsd1s1e      # | eval $TEAM
$DUMP /dev/rsd1s1f      # | eval $TEAM
tar cf $NTAPE /dos      # DOS C: Backup

echo -n "mkdump:: rewinding tape"
mt -f $TAPE rewind \
        && echo " done."

--


pgp p-key  http://www-swiss.ai.mit.edu/~bal/pks-toplev.html  >>> powered by <<<
ftp://sunsite.unc.edu/pub/Linux/system/Printing/aps-491.tgz  >>>    FreeBSD <<<

 
 
 

1. Trying to determine scsi tape density/block size/length for dump

Hi,

I recently picked up an Aiwa TD8000 (Travan 4/8GB - SCSI) and want to
test it with dump.  I've tried the following:

    /sbin/dump -0u -f /dev/rst0 /usr

my /usr filesystem is roughly 3GB but only at 25% capacity.

The output from dump shows the following:

    DUMP: estimate 780034 tape blocks on 20.02 tape(s).

Dump asked for a second tape at which point I cancelled the dump.

I was hoping someone could tell me what is the density/block size/length
of the tapes/drive.  Output from dmesg is as follows:

    st0(ahc0:4:0): Sequential-Access density code 0x45

The man page for mt only goes up to 0x17 and I am using a standard TR-4
cartridge.

I also tried /sbin/dump -0u -a -f /dev/rst0 /usr so as to let dump write
until the end of the tape and prompt for a new one, this worked without
a hitch, it only required 1 tape and I doubt it used most of it.

    DUMP: estimated 778113 tape blocks
    ...
    DUMP: DUMP: 779039 tape blocks on 1 volumes(s)    *** Looks like 1k
blocks***

I now know that I can include the -a switch and it will work but I don't
know that it is the most efficient method.  That's why I'd like to know
about the correct density/block size/length.

Thanx in advance,

David

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