What is the blocking factor?
The blocking factor is the block size that a tar record is written in ([blocking size] = [blocking factor] * 512). Because of limitations of earlier tape devices used with older UNIX systems, this blocking factor had to be defined before writing an archive, and you had to know what was used to read it back. This old requirement stills exists today in the tar format even though newer formats don’t necessary use it, they use newer more efficient methods since today’s hardware doesn’t dictate it’s use. You can set the default blocking factor that will be used in Tar98 under the “Options” pull down menu. The tape device drivers in Windows NT 4.0 restrict Tar98 from using blocking factors of over approximately 1024 (can vary depending on the tape device). This means that Tar98 sometimes can not read tapes written in UNIX at high blocking factors. This is generally not a problem since most tar tapes written in UNIX are blocked at 20, but SGI IRIX is an example of a platform that defaults to
