performance with LSI SAS 1064

[Scott Long]

Eric Anderson wrote:
> Scott Long wrote:
>> Eric Anderson wrote:
>>> Lutieri G. wrote:
>>>> I've make a test with dd command:
>>>>
>>>> # time dd if=/dev/zero of=./8gbfile bs=1024k count=8192
>>>> 8192+0 records in
>>>> 8192+0 records out
>>>> 8589934592 bytes transferred in 155.653213 secs (55186362 bytes/sec)
>>>> 0.007u 25.129s 2:35.69 16.1%    55+6039k 117+68628io 0pf+0w
>>>>
>>>> in other terminal i ran iostat while dd were running and I get this:
>>>>
>>>> # iostat -I 1
>>>>       tty             da0            pass0             cpu
>>>>  tin tout  KB/t xfrs   MB   KB/t xfrs   MB  us ni sy in id
>>>>    1   61 25.23 52958 1305.07   0.00   0  0.00   0  0  8  0 91
>>>>    0  184 127.48 434 54.03   0.00   0  0.00   0  0  5  0 95
>>>>    0   61 127.49 440 54.78   0.00   0  0.00   0  0  5  0 95
>>>>    0   61 127.75 445 55.52   0.00   0  0.00   0  0  5  0 95
>>>>    0   61 127.49 442 55.03   0.00   0  0.00   0  0  4  0 96
>>>>    0   61 127.49 436 54.28   0.00   0  0.00   0  0  5  0 95
>>>>    0   61 125.27 425 51.99   0.00   0  0.00   0  0  5  1 94
>>>>    0   61 118.14 393 45.34   0.00   0  0.00   0  0  3  0 97
>>>>
>>>> average  54MB/s with or without hw.mpt.enable_sata_wc seted in 
>>>> loader.conf file.
>>>>
>>>> is it a normal speed for this adapter?!
>>>>
>>>>
>>>
>>>
>>> I'm confused - you said in your first post you were getting 3MB/s, 
>>> where  above you show something like 55MB/s.
>>>
>>> You didn't say what kind of disks, or how many, the configuration, 
>>> etc - so it's hard to answer much.  The 55MB/s seems pretty decent 
>>> for many hard drives in a sequential use state (which is what dd 
>>> tests really).
>>>
>>> Your errors before were probably caused because your queue depth is 
>>> set to 255 (or 256?) and the adapter can't do that many.  You should 
>>> use camcontrol to reduce it, to maybe 32.  See the camcontrol man 
>>> page for the right usage.  It's something that needs setting on every 
>>> boot, so a startup file is a good place for it maybe.
>>>
>>> Eric
>>>
>>>
>>
>> Well, if he's using SATA (which I kinda assumed originally without
>> asking) then queue depth isn't going to matter; the MPT driver has no
>> interaction with how SATA NCQ operates, if he even has a rev of the
>> LSI chip that supports NCQ at all.  If he's using SAS, then queue
>> depth will only be a minor factor, CAM is pretty good at autosizing
>> the depth with minimal impact.  Now, if he's using SAS disks then
>> the boot tunable that I gave him will indeed have no impact at all.
>>
>> I believe that the Sun 4100 uses 2.5" disks, whether SATA or SAS.
>> 54MB/s is not all that bad for disks of this size.  It's pretty close
>> to what I would expect, actually.
> 
> If he's using a SAS Seagate 15k rpm 2.5" drive, he could see much better 
> than 55MB/s.  I have an LSI (PCI-X 133, model 1064 as he does) with some 
> Seagate 15k RPM drives, and I can get 100MB/s.  Tests were done on 
> FreeBSD 7-CURRENT, with write caching enabled on the drive. Here's some 
> of the numbers:
> 

Ah, I didn't know that Seagate made 15k drives in the 2.5" form factor, 
I was expecting just 7200 or 10k.

Scott