Current-Users archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: raidframe performance question



On Fri, 6 May 2011, Paul Goyette wrote:

Conclusion:  these disk drives suck!  It's not a raidframe problem....

Not really... this is a different problem and not reflective of the drive.

        dd if=/dev/zero bs=32k of=/dev/wd4d
...
got full. :) All the while, the systat output shows that the xfer-bytes is always 2K times the xfer-ops, so would indicate that something is breaking up the writes into 2K chunks.

That's what you get for writing to the block device :) The write data goes into the buffer cache which is going to use 2K blocks. You really, really want to be using the character device /dev/rwd4d. It works much better.

--
Michael L. Hitch                        mhitch%montana.edu@localhost
Computer Consultant
Information Technology Center
Montana State University        Bozeman, MT     USA


Home | Main Index | Thread Index | Old Index