binary format list log parameters and ascii list log parameters

Knight, Frederick Frederick.Knight at netapp.com
Wed Aug 17 15:25:22 PDT 2011


* From the T10 Reflector (t10 at t10.org), posted by:
* "Knight, Frederick" <Frederick.Knight at netapp.com>
*
"3.1.11 ASCII format list log parameter: a log parameter that contains
ASCII data in a list format. See 7.3.2.2.2.4"
So, now I need to understand what ASCII data is, so I look at 4.4.1:
"4.4.1 ASCII data field requirements
ASCII data fields shall contain only ASCII printable characters (i.e.,
code values 20h to 7Eh) and may be terminated with one or more ASCII
null (00h) characters."
Therefore, anything not in the range 20h to 7Eh makes it NOT ASCII.
Yes, I think a reference to 4.4.1 would be helpful.
I can't find any definition for what binary data is, so that means to
me, that it can be anything (byte values in the range 00h to FFh).
One key difference is the meaning of 00h.  If you report the data as
ASCII, then an application must stop parsing the data when it hits the
00h, but if it is BINARY data, then the application keeps parsing
(because 00h is part of the data).
So if I understood what Ralph said, I think that means I come the
opposite conclusion:
If the data is all in the range 20h to 7Eh, then it is ASCII, if ANY
byte contains a value not in that range, then it is BINARY.
  -  OR put another way  -  
The presence of one BINARY field in a log parameter pushes it out of the
ASCII format list camp and into the BINARY format list modus operandi.
	Fred
-----Original Message-----
From: Ralph Weber [mailto:roweber at IEEE.org] 
Sent: Wednesday, August 17, 2011 3:31 PM
To: T10 Reflector
Subject: Re: binary format list log parameters and ascii list log
parameters
* From the T10 Reflector (t10 at t10.org), posted by:
* Ralph Weber <roweber at ieee.org>
*
Okay! So, the question is which, if any, of the following
statements are true.
1) ASCII format list parameters contain *all* ASCII fields.
2) Binary format list parameters contain *all* binary fields.
To belabor the obvious, both statements cannot be true unless
people are *very* careful about how the construct log parameters.
IMHO The presence of the control byte and parameter length fields
in an ASCII format list parameter negates any possibility that
statement 1) can be true. The only statement in the pair which
can ever be 100% true is 2).
Based on this and a little leap of faith, I would like to claim
that the presence of one ASCII field in a log parameter pushes
it out of the Binary format list camp and into the ASCII format
list modus operandi.
Let's see if this sets the T10 Reflector on fire for a day
or two.
All the best,
.Ralph
P.S. If I have parsed Curtis' description correctly, the current
specification is correct ... a lucky break eh!
On 8/17/2011 1:17 PM, Ballard, Curtis C (StorageWorks) wrote:
> * From the T10 Reflector (t10 at t10.org), posted by:
> * "Ballard, Curtis C (StorageWorks)"<curtis.ballard at hp.com>
> *
> This question came up because SMC-3 leveraged a log page which has
parameters that are not entirely ASCII but sets the FORMAT AND LINKING
field to 01b, ASCII format list.  We're trying to figure out whether to
change to match what we think the FORMAT AND LINKING should be and be
inconsistent with existing implementations that may be able to be
leveraged but set the field differently or leave the field as is.
>
> The implication is that the ASCII format list log parameter value is
all ASCII but I can't find anything in SPC-4 (r31) that says what the
PARAMETER VALUE field of an ASCII format list log parameter contains.
The closest statement I found is the definition but that is never
referenced from any of the text describing the log parameter so it is a
bit tricky to find and even that doesn't really say the PARAMETER VALUE
is ASCII data, it just says the parameter 'contains' ASCII data.
>
> "3.1.11 ASCII format list log parameter: a log parameter that contains
ASCII data in a list format. See 7.3.2.2.2.4"
>
> Table 301 specifies the log parameter type as indicated by the FORMAT
AND LINKING field.
>
> "01b --- ASCII format list --- 7.3.2.2.2.4"
>
> Section 7.3.2.2.2.4 is only defining the parameter control byte and
doesn't define what is allowed to be in the PARAMETER VALUE field of an
ASCII format log parameter.
>
> The best reference I can find in that section is:
>
> "any log parameter that is defined to be an ASCII format (see 4.4.1)
list log parameter"
>
> But section 4.4.1 never defines what it means to be an "ASCII format".
That section is all about ASCII data fields and the sentence with that
reference is about a log parameter, not a data field.  Table 299 defines
the log parameter as containing fields and bits that aren't ASCII so it
isn't clear what the reference is intending to clarify.
>
> I think this paragraph should reference back to 3.1.11 after
'parameter' and probably not reference 4.4.1.
>
> The table that says how to fill in the FORMAT AND LINKING field sends
you back to table 301 and we start all over again.
>
> I believe that the intent was probably something like "the PARAMETER
VALUE field of a ASCII format list log parameter is an ASCII data field
(see 4.4.1)" but I can't prove that from the text I have.
>
> Curtis Ballard
> Hewlett Packard
>
> -----Original Message-----
> From: owner-t10 at t10.org [mailto:owner-t10 at t10.org] On Behalf Of Ralph
Weber
> Sent: Wednesday, August 17, 2011 10:46 AM
> To: T10 Reflector
> Subject: Re: binary format list log parameters and ascii list log
parameters
>
> * From the T10 Reflector (t10 at t10.org), posted by:
> * Ralph Weber<roweber at ieee.org>
> *
> Is it fair to assume that the difference between ASCII data
> and binary data is not of interest to the SMC working group?
>
> All the best,
>
> .Ralph
>
> On 8/17/2011 11:20 AM, Kevin D Butt wrote:
>> The SMC working group has a question.  SPC-4 describes binary format
>> list log parameters and ascii list log parameters.  The only
>> difference we can find is in the value in the FORMAT AND LINKING
>> field.  We can find no specified behavior differences.  What are the
>> functional differences besides the parameter control byte?
>>
>> Thanks,
>>
>> Kevin D. Butt
>> SCSI&  Fibre Channel Architect, Tape Firmware
>> Data Protection&  Retention
>> MS 6TYA, 9000 S. Rita Rd., Tucson, AZ 85744
>> Tel: 520-799-5280
>> Fax: 520-799-2723 (T/L:321)
>> Email address: kdbutt at us.ibm.com
>> http://www-03.ibm.com/servers/storage/
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