On 2006-02-22 11:21, Foro Linux wrote:
After about 12 hours of amtapetype execution, here it is:define tapetype HP-DAT72 {comment "HP-DAT72 USB interface (compression on) (tapes HP reference: C8010A)"length 31267 mbytes filemark 524 kbytes speed 1474 kps }
Does it make sense to use the length value of a tape drive having hardware compression on? If you want to use software compression, then you better disable hardware compression, because applying both *expands* the data, resulting a loss of effective tape capacity of about 15-20%. In that case you better set it closer to 36 Gbyte (= 33.5 Gibyte) giving you about 2 gigabyte extra capacity for such a tape. If you want to use hardware compression, then add to the 36 Gbyte some arbitrary percentage of what you hope the data will compress, like some 30% compression, giving 33.5 GiB / 0.70 = 50 Gibyte. Note that the prefixes in Amanda (K, M, G) are multiples of 1024, and not 1000, in ISO notation that should have been Ki, Mi and Gi. That is why a 36 Gbyte tape holds actually 33.5 Gibyte. See: http://en.wikipedia.org/wiki/Binary_prefix . -- Paul Bijnens, xplanation Technology Services Tel +32 16 397.511 Technologielaan 21 bus 2, B-3001 Leuven, BELGIUM Fax +32 16 397.512 http://www.xplanation.com/ email: [EMAIL PROTECTED] *********************************************************************** * I think I've got the hang of it now: exit, ^D, ^C, ^\, ^Z, ^Q, ^^, * * F6, quit, ZZ, :q, :q!, M-Z, ^X^C, logoff, logout, close, bye, /bye, * * stop, end, F3, ~., ^]c, +++ ATH, disconnect, halt, abort, hangup, * * PF4, F20, ^X^X, :D::D, KJOB, F14-f-e, F8-e, kill -1 $$, shutdown, * * init 0, kill -9 1, Alt-F4, Ctrl-Alt-Del, AltGr-NumLock, Stop-A, ... * * ... "Are you sure?" ... YES ... Phew ... I'm out * ***********************************************************************
