ISCSI slow to read from DELL MD3000i

[Sossi Andrej]

Danny Braniss wrote:
>> Danny Braniss wrote:
>>     
>>> wups, didn't read all your mail, sorry,
>>> try increasing tht tag opening, in the config file add
>>> 	tag = 64
>>> for example, or via camcontrol
>>>
>>> danny
>>>   
>>>       
>> I modify my iscsi.conf by adding tags = 64 (and no tag). Now works fine, 
>> about 43MB/s. Thank You very match.
>>
>> But what means this parameter?
>>     
>
> is the max number of commands that can be sent without waiting for ack. I set 
> it
> too concervative :-(
>   
I made many tests with different tags values and checked the writing 
speed with dd.
0 (default) -> ~850kB/s
1 -> ~850kB/s
2 -> ~6.5MB/s
3 -> ~40MB/s
4 -> ~49MB/s
8 -> ~49MB/s
...

I think that NAS server sends ACK after 4 commands. Is it correct? Is it 
possible that the NAS server modifies this behavior? Can I set tags at 4 
or is it smarter to keep it higher?

Thanks.

-- 
Sossi Andrej
-------------------------
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