Re: Supermicro SAS controller
On Thu, 03 May 2012 12:21:17 -0500, Stan Hoeppner wrote:
> On 5/2/2012 11:30 AM, Ramon Hofer wrote:
>> On Tue, 01 May 2012 15:43:13 -0500, Stan Hoeppner wrote:
>>
>>> On 5/1/2012 12:37 PM, Ramon Hofer wrote:
>>>
>>>> I have the RPC-4220 case with 20 howswap slots.
>>>
>>> You should have mentioned this sooner, as there is a better solution
>>> than buying 3 of the 9211-8i, which is $239*3= $717. And you end up
>>> with one SFF8087 port wasted.
>>>
>>> Instead, get a 24 port Intel 6Gb SAS expander:
>>> http://www.provantage.com/intel-res2sv240~7ITSP0V8.htm $238.24
>>>
>>> and the LSI 9240-4i, same LSISAS2008 chip as the 9211-8i:
>>> http://www.newegg.com/Product/Product.aspx?Item=N82E16816118129
>>> $189.99
>>>
>>> Total: $429
>>>
>>> W/4 extra SFF8087 cables (assuming you already have 2):
>>> http://www.newegg.com/Product/Product.aspx?Item=N82E16816116093 $60
>>>
>>> Total: $489
>>>
>>> This solution connects all 20 drives on all 5 backplanes to the HBA,
>>> and will give you ~1.5GB/s read throughput with 20 7.2k RPM drives
>>> using md RAID 5/6, and ~800MB/s with hardware or md RAID10.
>>>
>>> You connect the SFF8087 of the LSI card to port 0 of the SAS
>>> exapander.
>>> You then connect the remaining 5 ports to the 5 SFF8087 ports on the
>>> 5
>>> backplanes.
>>
>> Thanks alot for the suggestions. I have found a shop where I live and
>> will order them tomorrow. Do you have experience with these cards?
>
> Hi Ramon,
>
> Yes. Note that the Intel SAS expander has a PCIe x4 edge connector on
> the PCB and it also has a standard 4 pin Molex connector. The PCB has
> mounting holes to allow mounting it directly to your chassis via
> motherboard style brass or plastic stand-offs. This method may likely
> require drilling holes in your chassis. I often use this method to
> avoid wasting a PCIe slot. If you have plenty of free PCIe x4/8/16
> slots mount it in one as it's much easier. Note only power is drawn
> from the PCIe slot. There is no data xfer. Data xfer occurs only via
> the SFF8087 ports. Here's the manual:
> http://download.intel.com/support/motherboards/server/sb/
e93121003_res2sv240_hwug.pdf
> Nice picture and info:
> http://www.intel.com/content/www/us/en/servers/raid/raid-controller-
res2sv240.html
>
> Using the LSI 9240-4i HBA will be very similar to using the SuperMicro
> Marvell based SAS card, but better. Simply enter the BIOS at boot and
> configure the drives as you wish. This card is a real hardware RAID
> controller, not fakeraid, so you can use it as such. It simply lacks
> cache memory and the more advanced RAID features of LSI's higher end
> RAID cards. You can even install Debian onto and boot directly from a
> RAID volume on this card. If you wish to use mdraid instead, configure
> the drives as JBOD so md can see the individual drives.
>
> If you choose to use the hardware RAID feature, note that you can have a
> maximum of 16 drives per RAID volume. Thus, if you have 20 drives in
> that chassis, you'd want to create two RAID5 or two RAID10 volumes. If
> you use a separate boot/OS drive, you can do two hardware RAID5 arrays,
> then create an md linear or RAID0 array of these two hardware volumes so
> you have a single file system across all the drives. Lots of
> possibilities. All the info you could want/need for the 9240 is here:
> http://www.lsi.com/products/storagecomponents/Pages/
MegaRAIDSAS9240-4i.aspx
Thank you very much for all the information and the suggestion of the
cards.
I've just ordered them :-)
What would you suggest: Using the hardware raid functionality or use
mdadm?
I already used mdadm for some time now and like the ability to change the
arrays whilst the system is running. Can I do this with the hardware raid
too?
Thanks again
Ramon
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