On Mon, Dec 29, 2003 at 03:03:22PM +0100, Georg Rehfeld wrote: > Hello Karsten, Gene, all, > Hello Georg,
> ... > There seem to be no similar figures for taping and the tape speed > seems to vary largely: > > size speed speed > MB MB/s graph > > 102 1.8 ******* > 108 2.0 ******** > 113 1.7 ******* > 141 2.4 ********** > 227 1.9 ******** > 228 2.1 ******** > 251 1.0 **** > 253 2.1 ******** > 292 7.0 **************************** > 294 1.9 ******** > 328 3.2 ************* ... > > (All sizes reasonable large, all taping done from holding disk, all > values from one backup run) > > The ratio of tape speeds is nearly 1:9, a tendency is: larger files > tape faster, when looking at only sizes > 500 MB the ratio is only > 1:3.6 Georg, might you be using HW compression? If so, might this large variation in taping speeds actually be greatly influenced by the compressibility of your data? I just looked at a report of mine from last evening. It includes flushes from several days (forgot to change magazines :(( ) plus last nights run. I only see variation from 0.85 - 1.10 MB/s. Tapetype had reported 1.05 MB/s. jl -- Jon H. LaBadie [EMAIL PROTECTED] JG Computing 4455 Province Line Road (609) 252-0159 Princeton, NJ 08540-4322 (609) 683-7220 (fax)
