PERC4e/Di and QLE2360 Performance numbers

JACOB_LIBERMAN@Dell.com JACOB_LIBERMAN at Dell.com
Thu Jul 28 15:30:00 CDT 2005


Anjan,

Please send your current controller cache settings and verify write
cache is enabled. Also send a description of the LUN youre writing to...
Number of disk spindles, type/speed of drives, etc.

Finally, you can try hard-setting the qlogic to point to point (if youre
going through a switch) and speed to 2GB. Like some NICs and switch
combinations, the autosensing does not always work correctly.

You can download a white paper from powerlink that describes performance
tuning and best practices for clariion arrays. I believe they recommend
dedicating the large majority (>%90) of your cache to write caching but
you would need to double check.

Thanks, jacob 

> -----Original Message-----
> From: linux-poweredge-bounces at dell.com 
> [mailto:linux-poweredge-bounces at dell.com] On Behalf Of Anjan Dave
> Sent: Thursday, July 28, 2005 1:40 PM
> To: Anjan Dave; linux-poweredge-Lists
> Subject: RE: PERC4e/Di and QLE2360 Performance numbers
> 
> I got one response on this, suggesting increasing the 
> vm.max-readahead to 2048 and disabling the read cache on the 
> CX300 SP. Changing the max-readahead to 2048 yielded a bit 
> lower performance on read and writes compared to the 256 
> value. I didn't turn off the read cache on the SP cause of other luns.
> 
>  
> 
> On the same machine, with RHAS 4.0 (u1), I get about 95MB/sec 
> on writes and about 256MB/sec max on read requests (Vs. 
> 94MB/sec and 154MB/sec on RHAS 3.0 u5, shown below). This is 
> for the local RAID10 setup on the PERC4e.
> 
>  
> 
> Same tests on the EMC LUN yields only 70MB/sec on Writes and 
> about 67MB/sec on Reads, which is worse than the previous 
> numbers on RHAS3.0.
> 
>  
> 
> Am I missing something important here? 
> 
>  
> 
> The qlogic driver is:
> 
>  
> 
> QLogic PCI to Fibre Channel Host Adapter for QLE2360:
> 
>         Firmware version 3.03.13 IPX, Driver version 8.00.03b
> 
>  
> 
> Here are the (EMC) settings on the HBA:
> 
>  
> 
> HBA Port 0 - QLE2360  Port Name: 21-00-00-E0-8B-1E-8A-26 Port 
> ID: 01-01-00
> 
> --------------------------------------------------------------
> ---------------
> 
> Connection Options           : 2 - Loop Preferred, Otherwise 
> Point-to-Point
> 
> Data Rate                    : Auto
> 
> Frame Size                   : 2048
> 
> Hard Loop ID                 : 0
> 
> Loop Reset Delay (seconds)   : 5
> 
> Enable Host HBA BIOS         : Disabled
> 
> Enable Hard Loop ID          : Disabled
> 
> Enable FC Tape Support       : Enabled
> 
> Operation Mode               : 0 - Interrupt for every I/O completion
> 
> Interrupt Delay Timer (100ms): 0
> 
> Execution Throttle           : 256
> 
> Enable Extended Error Logging: Disabled
> 
> Login Retry Count            : 8
> 
> Enable LIP Reset             : Disabled
> 
> Port Down Retry Count        : 45
> 
> Enable LIP Full Login        : Enabled
> 
> Link Down Timeout (seconds)  : 45
> 
> Enable Target Reset          : Enabled
> 
> LUNs Per Target              : 256
> 
>  
> 
>  
> 
> Appreciate if someone has more information/reference 
> improving the performance especially the qlogic hba.
> 
>  
> 
> Thanks,
> Anjan
> 
>  
> 
>  
> 
> ________________________________
> 
> From: Anjan Dave
> Sent: Wednesday, July 20, 2005 11:15 AM
> To: linux-poweredge at dell.com
> Subject: PERC4e/Di and QLE2360 Performance numbers
> 
>  
> 
> Hi,
> 
>  
> 
> I ran some IOZONE tests on a 6850 with both the above cards 
> present in the system. The results are not staggering, but 
> after reading a bunch of similar posts, I am wondering if the 
> numbers I am seeing are at least similar to what other people 
> are getting and not that I have some important tunable left out...
> 
>  
> 
> Common: 6850 (3GHz/1MB cache, 12GB), 4 x 73GB (15K) RAID 10, 
> RHAS 3.0 Update5, Kernel is 2.4.21-32.0.1.ELsmp, Megaraid 2.x 
> (need to double-check, but whatever comes standard in this release).
> 
> The Iozone command used had the 16g option and random read 
> and write option.
> 
>  
> 
> Test1: on the local 100GB RAID-10 volume yields about 
> 94MB/sec on Writes and about 154MB/sec on Reads - not random
> 
>  
> 
> Test2: Via the QLE2360-E, attached to CX300 on a 130GB 
> RAID-10 LUN (aligned to element size of 128KB) with read and 
> write cache enabled. I also had the min-readahead and 
> max-readahead set to 256 in /proc/vm. This time it yields 
> 81MB/sec for Writes and about 100MB/sec for Reads - not random
> 
>  
> 
> The qle2360 card's BIOS is not the latest (1.05) but has all 
> the EMC specific values set in it. 
> 
>  
> 
> Is there anything else I can do to get more IO out of this 
> setup, or this is what I get for such a platform? Is RHAS 
> 4.0/2.6 kernel expected to be better at handling IO?
> 
>  
> 
>  
> 
> Thanks,
> Anjan
> 
>  
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