[ale] HOWTO->stop TapeDrive from "shoeshining" ?

[James P. Kinney III]

A few sugestions:

1. Clean the tape drive. This lets the writes be more correct first
time.

2. Most "shoe-shine" is caused by buffer underruns. If you are backing
up from a network, pull the data to a temp place on the hard drive
attached the the tape drive machine and write from that. If the drive to
be backed up is already on the tape machine, there is a process with a
higher priority hitting the drive and letting the buffer run dry. Add a
temp drive, dump to that then write from that drive. If it's possible,
put the temp drive and the tape drive on the same SCSI controller, and
all other drives on a seperate controller. No more bandwidth fighting!

3. Get a drive that support variable speed write. Ecrix VXA has a
variable speed tape path to slow down the tape if the buffer is running
dry. That may also be an option on the DLT drive. But they are $$$! 

4. Turn off "error correction" during the write (an option on some
drives). Replace it with a post-write verification check that rewrites
any file that does not pass verification. 

On Sun, 2001-11-25 at 09:55, Courtney Thomas wrote:
> Good Morning !
> 
> Trying to backup Debian-2.4.6 [750MHZ 256MB ram] onto an Exabyte 8500
> SCSI DAT, I have tried.........
> 
> 	dump 0u -B5000000 /<dir> | 'buffer -s 64k -p 75 -o /dev/tape'
> 
> with no improvement in the back&forthing with intermittent pauses, of
> the cpu&tape.
> 
> Suggestions ?
> 
> Appreciatively,
> 
> Courtney
> 
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-- 
James P. Kinney III   \Changing the mobile computing world/
President and COO      \          one Linux user         /
Local Net Solutions,LLC \           at a time.          /
770-493-8244             \.___________________________./

GPG ID: 829C6CA7 James P. Kinney III (M.S. Physics)
<jkinney at localnetsolutions.com>
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