On Mon, Nov 2, 2009 at 9:36 PM, NeilBrown <neilb@xxxxxxx> wrote: > On Tue, November 3, 2009 2:03 am, Jon Nelson wrote: >> On Mon, Nov 2, 2009 at 8:54 AM, Bill Davidsen <davidsen@xxxxxxx> wrote: >>> Jon Nelson wrote: >>>> >>>> I have a 4 disk raid6. The disks are individually capable of (at >>>> least) 75MB/s on average. >>>> The raid6 looks like this: >>>> >>>> md0 : active raid6 sda4[0] sdc4[5] sdd4[4] sdb4[6] >>>> 613409536 blocks super 1.1 level 6, 64k chunk, algorithm 2 [4/4] >>>> [UUUU] >>>> >>>> The raid serves basically as an lvm physical volume. >>>> >>>> While rsyncing a file from an ext3 filesystem to a jfs filesystem, I >>>> am observing speeds in the 10-15MB/s range. >>>> That seems really really slow. >>>> >>>> >>> >>> It is really slow, recent kernels seem to be unsuitable for use as large >>> file servers, as the performance is, as you described it, "unbelievably >>> bad." >> >> Yeah. I'm hoping that the 2.6.31.XX stable kernel series gets some of >> these improvements, the .27 series has been not the most stable for me >> either. 2.6.27.25 was the last rock-solid of the .27 series for me. > > I wouldn't get your hopes up... > I did some limited testing of simple writes to ext2 and the current > 32-pre kernel is noticably slower than .26 .27 .28 .29 .. (that is as > far as I got with testing... I should write a script and leave it running > overnight to get a broader picture). > > NeilBrown > > -- > 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 > Maybe my speed results even after the 'fix' are also this issue: I expect each of my drives is capable of at least 8MB/sec sustained (highly pessimistic). 2909829120 blocks super 1.1 level 6, 128k chunk, algorithm 18 [8/8] [UUUUUUUU] [==>..................] reshape = 10.4% (50708096/484971520) finish=3989.0min speed=1813K/sec The 'backup file' is on a separate raid 1 device and approximately 25 mb in size. My cpu has virtually no load and I've got gigs of memory free. (also sorry for duplicates, I hit reply at the top instead of reply to all at the bottom out of habit) -- 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
