mcba@newt.phys.unsw.OZ.AU (Michael C. B. Ashley) (03/15/91)
I was wondering if other people have noticed the impact that writing to a TK50 magtape drive has on the system performance of a DECstation 5000. I'm running a DS5000/200 with 88 Mbytes, ULTRIX 4.0, swapping on three partitions of 280 MBytes each. When I write to a TK50 the CPU spends about 85% of the time in "system" mode, and interactive response plummets (incidentally, I'm using tar to write the tape). The tar process itself only uses a fraction of a percent of the CPU. I've used "top", "monitor", "ps", and "pmon" to try and work out what is going on, without luck. The missing CPU time does not appear to be attributed to any process that I can find. Is this a known problem, or is there something wrong with my TK50? Running /etc/uerf shows no errors. Thanks! Michael Ashley mcba@newt.phys.unsw.oz.au