From: George W. D. I. <du...@um...> - 2003-07-02 04:33:15
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On Wed, 2 Jul 2003, Nuno Silva wrote: > the 1st time you run that tar it will take 5mins. the second time you > run it it will take 30 seconds. why? because the host has the uml's > filesystem in it's cache. now the other 7 umls are living in the swap :) Our solution with UMLinux (now FAUMachine) was as follows: * Put the "physical" memory file on a ramdisk * Put the virtual disk in a partition, and access it via the /dev/raw devices. Do 'man raw' for more details on the raw devices, but basically it bypasses the block layer and, if available, does DMA. The only caveat is that reads & writes must be block-aligned in memory. Does anyone know if UML can use the raw devices? I haven't tried it yet. -George -- +-------------------+----------------------------------------- | du...@um... | http://www-personal.umich.edu/~dunlapg +-------------------+----------------------------------------- | "Pointing and clicking is like a baby pointing and | screaming. Stuff gets done, but it's a lot faster to ask | in an intelligible language. I'll never give up a great | shell... for a prettier interface." | -SHEENmaster on Slashdot.org +------------------------------------------------------------ | Outlaw Junk Email! Support HR 1748 (www.cauce.org) |