Dell PE2950 - SAS 6/iR

[FreeBSD]

Maciej Suszko a écrit :
> FreeBSD <freebsd at optiksecurite.com> wrote:
>   
>> Maciej Suszko a écrit :
>>     
>>> I think about buying Dell PE2950 with SAS 6/iR integrated RAID
>>> controller. It would be double Intel Quad Core Xeon E5420 with 3.5"
>>> SAS 15k RPM disks connected to SAS 6/iR RAID controller.
>>>
>>> I'm curious if anyone is running FreeBSD-7.0-RELEASE on such machine
>>> and if there any problems with this controller - is SAS 6/iR
>>> supported by mpt or mfi? Anyone happily using it?
>>>   
>>>       
>> I never tried SAS 6 but I have SAS 5 in a few Dell servers and it's 
>> performance is horrible. I tried some tips I read to optimize the 
>> performance but none worked (I must admit that I didn't tried that
>> hard but still...). Just to compare, I have the exact same disk (the
>> same 3,5" SAS 15K that you plan to buy) in a PowerEdge 860 with SAS 5
>> and in a PowerEdge 1950 with PERC5 (both in RAID 1) and the
>> performance are like day and night (tested with dbench):
>> SAS 5: Throughput 98.9811 MB/sec 4 procs
>> PERC5: Throughput 321.704 MB/sec 4 procs
>>
>> The last server I bought is a PowerEdge 840 with PERC5 but this time 
>> with 7200RPM SATA drives (3 in RAID 5) and the performance is still 
>> impressive : Throughput 266.81 MB/sec 4 procs
>>
>> I highly recommand upgrading to the PERC controller.
>>
>> SAS5 is recognized by the mpt driver and PERC5 by mfi.
>>
>> YMMV,
>>
>> Martin
>>     
>
> Thanks for reply Martin,
>
> I think I'm not gonna take the risk and I stay with PERC5 controller.
> Have you used integrated PERC5 or external one? And one more question -
> how about controller monitoring  - there is a sysutils/linux-megacli,
> have you tested it? Is it working with your PERC?
>   
I have the PERC5/i but I can't say that it is "integrated". It's a
PCI-Express x4, IIRC. I think that the difference between the I and E is
that the E would have an external connector, but I can't say for sure. I
think you should stay with the PERC5/i and I think that the E is more
expensive too.

For the monitoring, I never tried linux-megacli because (for no good
reason) I'm not a fan of linux emulation. Instead, I did a small shell
script that grep /var/log/messages for entries related to mfi and email it
to me. The messages in case of failure are pretty clear. I put the script
in crontab so that it runs every half-hour. It does the job very well for
me.

Martin