Messages in this thread | | | Date | Thu, 27 May 1999 13:16:33 +0200 | From | Pavel Machek <> | Subject | Re: disk requst queue problem |
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Hi!
> When I do dd if=/dev/zero of=/dev/hda9, all other disk operations > (including swapping) are suspended until dd terminates. The same with dd > if=/dev/zero of=foo. I have ide disk. There's probably bad implementation > of request queue. Something like request ages should be implemented. Has > anyone another idea what to do with it?
Mikulas shown me and it really is problem. I was unable to ssh to our server within _minute_ when dd ran. We tried to reproduce it on 2.0 system with scsi and it did not work. It is pretty effective DoS attack and I think something like that happens in real life, too. Notice that you have to _write_ on disk, reading does not work.
Pavel -- The best software in life is free (not shareware)! Pavel GCM d? s-: !g p?:+ au- a--@ w+ v- C++@ UL+++ L++ N++ E++ W--- M- Y- R+
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