Bug #884

Updated by tuxillo 8 months ago

During testing drive with dd I noticed that there are serious performance

problems. Programs which need disk access, block for 10 and more seconds.

Sometimes they don't continue the work until dd is finished. Raw disk access

(ie not writing to file, but directly to the disk) is reported to be OK (I

can't test it myself).



All tests are done with this command:

dd if=/dev/zero of=./file bs=4096k count=1000



Syncing after each dd helps to reproduce it more reliably (cache?).



There is one more strange thing in running these tests. I looked at memory

stats in top before and after running dd.



Before:

Mem: 42M Active, 40M Inact, 95M Wired, 304K Cache, 53M Buf, 795M Free

After:

Mem: 70M Active, 679M Inact, 175M Wired, 47M Cache, 109M Buf, 1752K Free



And as a side effect - I can't get my network interfaces up any more after

running dd - "em0: Could not setup receive strucutres".

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