> >yup. anyway, compression is off now (and was already set to none > > when I sent this one). > > Drive hardware compression usually has a mind of its own. In > particular, many drives look at the header, and set the compression > on if the tape has ever been written to with the compression turned > on, and there is nothing amanda can do about fixing that. Many > drives have an indicator on the front panel called "dc", and if its > lit while the tape is being written, then the compression is on. > > The only way I know of to fix such a tape is: > rewind it > read out the label to a scratch file using dd > rewind it again > turn the compression off with "mt -f device whatever turns it off" > dd that scratch file back to the tape using the non-rewinding device > dd at least enough data from /dev/zero to force the drive to > flush its > buffers. This will force the drive to turn the header compression > flag off and that tape will not be compressed again unless you turn > compression back on. > > I noted in a previous msg that your drive is a DDS3. This drive > should be able to stream about 700k/second. I'd concur that the > holding disk isn't enabled, or is somehow miss-configured and that > the drive is shoe-shineing the tape due to running out of data and > having to back up and restart once the buffer is up to 50% full or > so. Thats a speed killer in addition to causing a lot of wear and > tear on both the tape and the headwheel with all that starting and > stopping that we suspect it may be doing.
I created a different configuration to backup a remote box, just to make sure it could me better, and have a look at the results: STATISTICS: Total Full Daily -------- -------- -------- Estimate Time (hrs:min) 0:00 Run Time (hrs:min) 0:11 Dump Time (hrs:min) 0:06 0:06 0:00 Output Size (meg) 317.0 317.0 0.0 Original Size (meg) 317.0 317.0 0.0 Avg Compressed Size (%) -- -- -- Filesystems Dumped 1 1 0 Avg Dump Rate (k/s) 870.2 870.2 -- Tape Time (hrs:min) 0:04 0:04 0:00 Tape Size (meg) 317.0 317.0 0.0 Tape Used (%) 2.7 2.7 0.0 Filesystems Taped 1 1 0 Avg Tp Write Rate (k/s) 1249.0 1249.0 -- USAGE BY TAPE: Label Time Size % Nb fenestra01 0:04 317.0 2.7 1 DUMP SUMMARY: DUMPER STATS TAPER STATS HOSTNAME DISK L ORIG-KB OUT-KB COMP% MMM:SS KB/s MMM:SS KB/s -------------------------- --------------------------------- ------------ arara /root 0 324630 324630 -- 6:13 870.2 4:201249.0 (brought to you by Amanda version 2.4.4p2) --- Certain disclaimers and policies apply to all email sent from Memetrics. For the full text of these disclaimers and policies see <a href="http://www.memetrics.com/emailpolicy.html">http://www.memetrics.com/em ailpolicy.html</a>