> 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. > If your data is highly compressible or you have some large sparse files this is totally possbile. The hardware compresson 2x is no limit at all. It is just a number that the drive manufacturer claims will be the average and at least for me it is generally way too high. With the medical images, I have to backup I get 1.2x to 1.5x most of the time however there are times I get as much as 3.5x.
John John ------------------------------------------------------- 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
