Re: unbelievably bad performance: 2.6.27.37 and raid6

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

 



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

[Index of Archives]     [Linux RAID Wiki]     [ATA RAID]     [Linux SCSI Target Infrastructure]     [Linux Block]     [Linux IDE]     [Linux SCSI]     [Linux Hams]     [Device Mapper]     [Device Mapper Cryptographics]     [Kernel]     [Linux Admin]     [Linux Net]     [GFS]     [RPM]     [git]     [Yosemite Forum]


  Powered by Linux