Path: utzoo!mnetor!motto!ecijmm!ecicrl!clewis From: clewis@ecicrl.UUCP Newsgroups: comp.unix.microport Subject: Re: Efficient tape I/O with 386/ix; How?? Keywords: streaming tape interactive slow Message-ID: <161@ecicrl.UUCP> Date: 14 Dec 88 17:49:29 GMT References: <317@focsys.UUCP> Reply-To: clewis@ecicrl.UUCP (Chris Lewis) Organization: Elegant Communications Inc. (CRL Division) Lines: 34 In article <317@focsys.UUCP> larry@focsys.UUCP (Larry Williamson) writes: >Streaming tape I/O with 386/ix seems to be rather slow. The drive >is not streaming very well. It spends most of it's time stopping >and starting. I'm using an Everex Excel 60 with a long controller >card. > >The command I've used is > find . -print | cpio -ovc >/dev/rmt0 Try this instead find . -print | cpio -ovcC1048576 >/dev/rmt0 Mentioned in the HCR release notes. Can be retrofitted into the sysadm backup and restore scripts if you want (the HCR note contains details of which files and where to fix). Another alternative which works in most 386 UNIXs (not Xenix) is piping the output of your program thru dd with a bs of 1mb. Eg: tar cvf - | dd bs=1024k > /dev/rmt0 (Xenix dd can't handle that much bs ;-) Similar tricks are also useful for speeding up cpio's, tar's or similar programs to floppies. Bell Tech UNIX (actually a somewhat older version of 386/ix) had utilities such as "star" and "stream". All they were were pipes of some utility thru a program with a large (default 3Mb!) buffer. -- Chris Lewis, Markham, Ontario, Canada {uunet!attcan,utgpu,yunexus,utzoo}!lsuc!ecicrl!clewis Ferret Mailing list: ...!lsuc!gate!eci386!ferret-request (or lsuc!gate!eci386!clewis or lsuc!clewis)