Hi everyone,
I've been running Bacula version 1.38.2 on a 6.0-STABLE FreeBSD system
with a Postgres (v7.4) backend for several months. The machine hosting
the director is connected to an Exabyte 221L tape library (via SCSI)
with an IBM LTO-2 drive, but we currently only have LTO-1 tapes.
With this setup (specifically, the LTO-1 tapes) I should be able to
store _at most_ 200GB of data per tape (100GB of storage times the
mythical 2x compression claimed by the hardware). Bacula reports,
however, that I am storing anywhere from 300 to 480 GB per tape. That
is, when I add up the nightly reports of how many sd bytes are written
before a tape gets changed out, or when I run "list volumes" from
bconsole and look at the "volbytes" column, both show well over the
expected 200GB of data being stored on a fresh tape. I have been
watching this for several months now and have noted this behavior
occuring on at least fifteen separate tapes.
As far as scheduling goes, I do full backups every weekend and
incrementals inbetween and I am spooling 100GB to disk before writing to
tape.
btape works famously and reports no problems (though I could never get
it to test tape spanning correctly, but I believe this problem is noted
in the documentation). I have read and re-read the tape documentation
and have configured my tape drive according to the suggested FreeBSD
parameters:
For the tape drive itself:
mt -f /dev/nsa0 seteotmodel 2
mt -f /dev/nsa0 blocksize 0
mt -f /dev/nsa0 comp enable
For the bacula-sd:
Hardware End of Medium = no
BSF at EOM = yes
Backward Space Record = no
Backward Space File = no
Fast Forward Space File = no
TWO EOF = yes
Doing simple restores of small amounts of data has proven successful,
but I have yet to try a restore that would span an entire tape.
This worries me because it seems to me that this means either (1) data
is getting overwritten on each tape, (2) I have an enchanted tape
library or (3) Bacula is ruthlessly efficient and has, once again,
outsmarted me in it's backup strategies.
Any thoughts or suggestions about how to proceed would be much appreciated.
Thanks!
Mark
-------------------------------------------------------
Using Tomcat but need to do more? Need to support web services, security?
Get stuff done quickly with pre-integrated technology to make your job easier
Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642
_______________________________________________
Bacula-users mailing list
Bacula-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/bacula-users
