Re: Dell Perc 5/i Performance issues

From: Garrett Cooper <yanefbsd_at_gmail.com>
Date: Sat, 19 Jun 2010 21:31:48 -0700
On Sat, Jun 19, 2010 at 7:56 PM, Scott Long <scottl_at_samsco.org> wrote:
> On Jun 19, 2010, at 5:32 AM, Garrett Cooper wrote:
>> On Sat, Jun 19, 2010 at 4:24 AM, Garrett Cooper <yanefbsd_at_gmail.com> wrote:
>>> On Sat, Jun 19, 2010 at 4:21 AM, oizs <oizs_at_freemail.hu> wrote:
>>>> Since I tested it on different kind of os's, and with at least 5 testing
>>>> applications, I don't think that would be the case.
>>>>
>>>> On 2010.06.19. 13:17, Garrett Cooper wrote:
>>>>>
>>>>> On Sat, Jun 19, 2010 at 2:58 AM, oizs<oizs_at_freemail.hu>  wrote:
>>>>>
>>>>>>
>>>>>> I tried almost everything raid 0 1 5 10 with all kind of stripes
>>>>>> 32/64/128
>>>>>> and settings direct io/cached/read-ahead/wt/wb/disk-cache but nothing
>>>>>> seems
>>>>>> to work.
>>>>>> I changed the card to another dell perc 5 which had an older firmware.
>>>>>> Tried
>>>>>> 4 kind of motherboards even tried changing the os to linux and windows
>>>>>> xp/7.
>>>>>> In windows I got some funny results 1.3MB/s with write-back and 150MB/s
>>>>>> reads with 5 disks in raid0.
>>>>>> I just wanted to have a hw raid with no problems since the motherboard
>>>>>> 88sx7042 and bsd did not like eachother.
>>>>>>
>>>>>> On 2010.06.19. 11:07, Svein Skogen (Listmail Account) wrote:
>>>>>>
>>>>>>>
>>>>>>> On 18.06.2010 01:50, oizs wrote:
>>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>> Hi,
>>>>>>>>
>>>>>>>> I've bought a Dell Perc 5/i because I couldn't make the onboard marvell
>>>>>>>> 88sx7042 work with 8.0/8.1 or current, but as lucky as I am, the best I
>>>>>>>> can do with 4x1.5tb samsung in raid5 is 60MB/s writes and 90MB/s reads,
>>>>>>>> with bbu/write-back/adaptive-read-ahead.
>>>>>>>>
>>>>>>>> I was expecting at least twice of that, and I'm not sure what can I do
>>>>>>>> to get that speed. (I've read man 7 tuning with no success)
>>>>>>>>
>>>>>>>> As far as I know this controller should be as fast as on other systems.
>>>>>>>> (Freebsd.org mx1 has one of these cards.)
>>>>>>>>
>>>>>>>> I'm hoping somebody on the list reads this and helps because I can't
>>>>>>>> afford to buy another card.
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>> I've lost track of what actual boards Dell has OEMized to make the
>>>>>>> various PERCs, but if I remember somewhat correctly, the PERC5 is
>>>>>>> basically an LSI Megaraid SAS 8308elp with different labels and
>>>>>>> firmware?
>>>>>>>
>>>>>>> If so, I've got that exact controller (minus the dell labels and
>>>>>>> firmware) in my primary storage box here, and yes, you SHOULD be able to
>>>>>>> get more performance out of it. What's your strip sizes and logical disk
>>>>>>> layout?
>>>>>>>
>>>>>>> (I've got the same board running on 8x 1T5 Seagates in RAID5+0, and that
>>>>>>> setup easily pulls 5 times the values you're seeing, and by all logic
>>>>>>> you should see about half of what I'm seeing)
>>>>>>>
>>>>>
>>>>> Dumb question: are you sure that the problem that you're seeing isn't
>>>>> in fact inhibited by the application that you're getting `performance'
>>>>> results with?
>>>
>>> If your applications aren't well suited for your hardware's
>>> capabilities, then of course performance will be bad.
>>
>> Furthermore, if the performance applications and your use scenarios
>> are centered around reading, as opposed to writing, there is an option
>> within mficontrol and the mfi(4) interface where you can actually
>> enable read-ahead, instead of writeback (you unfortunately can't
>> enable both scenarios). I realize that this is an artificial
>> improvement in a way, but you should judge whether or not your
>> application will be doing more reading than writing in whatever
>> capacity it's doing...
>>
>> HTH,
>
> No, that doesn't help.  I wrote the driver, and I have no flipping clue what you're talking about.

    Nevermind. It was a misunderstanding of what the subcommands...
    - mfiutil cache .. enable
    - mfiutil cache .. reads enable
    - mfiutil cache .. writes enable
    ... do.
-Garrett
Received on Sun Jun 20 2010 - 02:31:50 UTC

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