> On Wed, 16 Jun 2010 18:23:36 -0400 > Increasing stripe cache size from the default of 256 should help > immensely. > > echo 16384 > /sys/block/md0/md/stripe_cache_size > > Be warned that this consumes (^that amount * 4096 * number of disks) bytes > of > RAM. Some benchmarks: Hello. Thank you for the quick suggestions! First I need to correct myself. I only have the slowdown when writing to the server. Reads from the server are usually in the 60-70MB/sec range regardless of file size. Prior to the change above, on a 2GB file, I would start off the write (to the server) at 70MB/sec and end at about 35MB/sec. CPU usage was at 100% with the md0 using about 70% CPU and smb using 30% with flush sometimes jumping in at 30%. Wait states remained below 10%. After the change, on a 2GB file I would start the write at 70MB/sec and end about 55MB/sec (nice improvement!). Switched to a 5GB file and the write ended around 35MB/sec. At the beginning smbd would star with 50% CPU but gradually go down to 30% with md0 ramping up to 70% and flush jumping in from time to time at 30%. This information is all coming from top. If I should use something else that will get more accurate readings, please let me know. With one change my performance greatly increased but I would like to see more. Is there anything else I can do? I'm hoping to get sustainable 60MB/sec writes. Is that possible? Thank you if you have read this far! :) --- Will Y. -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. -- 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
