Actually my problem as written in the subject of the mail was that the sequential read was slow. Somebody suggested to use a file instead of the raw partition. If the file was detected as sparse (who does that??), it would be even faster to read not slower. nicolae On 03/18/2010 03:40 AM, Michael Evans wrote: > First off, why not use a hard disk benchmark utility (their names > escape me aside from Bonnie++) which has these issues worked out? > > Second, if you absolutely must try to do a benchmark with basic tools > (that buffer and use cache) try this: > > dd if=/dev/zero bs=1M count=10000 | tr '\0' 't' > testfile > dd if=testfile of=/dev/null bs=1M > > You may note that you'll be writing a file with Ts instead of a file > with 0's; my method should not be detected as sparse, where as the > case with zeros probably will be detected as sparse and simply not > stored. > > If in doubt you can check the size of the file on disk with ls -ls > If I'm reading the output correctly the left most column (size on > disk) is in kilobyte units, even on a 4kb cluster EXT4 filesystem -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
