[cisco-voip] Number of Partitions in CSS max 1024 chars?

[Anthony Holloway]

Exactly right Jason.  There's two concepts going on here in this discussion:

1) How short do you have to make the partition names in order to cram as
many partitions in to your CSS as you need.

2) How many partition names, meaningful ones anyway, can you create with a
very short name.

Just because you can cram 341 partitions into a CSS with only using two
characters, doesn't mean you should.  As the amount of two character
partition names which could possibly be meaningful is limited.

What we should all be looking for is a balance between meaningful names and
quantity of partitions needed in a single CSS.  Luckily, I don't think many
designs require fixed length partition names 100% of the time.  Sure, with
site codes and naming conventions it kind of just happens (E.g., SFO_PT,
MSP_PT, MIA_PT, etc.), but not for things like "Block_Local_PT" or
"VM_Ports_PT", etc.

Here's a chart showing the relationship between partition name length and
quantity of partitions in a CSS:

[image: Inline image 1]

The reason for the steep dropoff is the size of the separator overhead
relative to the length of the name.  E.g., In a two character name, 1/3 of
the total space occupied is the separator (AA,).  In a nine character name,
1/10 of the total space occupied is the separator (Employees,).  So,
there's not much change between say a 30 character name, and a 31 character
name.

On Mon, Apr 20, 2015 at 3:44 PM Jason Aarons (AM) <
jason.aarons at dimensiondata.com> wrote:

>  To clarify it’s not the variation of characters, but the maximum number
> of characters in a CSS is 1024.
>
>
>
> Thus Chery’s birthday is clearly Dec 25th.
>
>
>
> *From:* avholloway at gmail.com [mailto:avholloway at gmail.com] *On Behalf Of *Anthony
> Holloway
> *Sent:* Monday, April 20, 2015 4:41 PM
> *To:* Lelio Fulgenzi; Jason Aarons (AM)
> *Cc:* cisco-voip (cisco-voip at puck.nether.net)
>
>
> *Subject:* Re: [cisco-voip] Number of Partitions in CSS max 1024 chars?
>
>
>
>
>
> Just sharing some interesting data on the topic...
>
>
>
> The validation regex for the name of a partition is:  ^[a-zA-Z
> 0-9_-]{1,50}$
>
>
>
> However, it's case-insensitive, and though a space is a valid character,
> you cannot start or end a name with spaces, they will be removed.
>
>
>
> You can see the space removing function in the JS below; I've extracted
> the following functions:
>
>
>
> // function jTrim:
>
> //   javascript version of VBScript Trim function
>
> // inputs:
>
> //   s - a string object
>
> // returns:
>
> //   s with leading and trailing spaces removed (spaces within string
> remain intact)
>
> //
>
> function jTrim(s)
>
> {
>
>   if (typeof(s) == "string")
>
>     s = jRTrim(jLTrim(s));
>
>   return s;
>
> }
>
>
>
> function isNameValid(nameVal) {
>
>
>
>   // We need to split the name based on the line feed character for
> Explorer Browsers.
>
>   // Otherwise, the validiation check will fail
>
>   // This check is only needed for Explorer, Netscape is ok
>
>   //
>
>   var nameArray = nameVal.split(/\r+/);
>
>   nameVal = jTrim(nameArray[0]);
>
>
>
>   reset_errors(errorArr);
>
>   var msg = "";
>
>   var check = /^[a-zA-Z 0-9_-]{1,50}$/;
>
>   errorArr[0] = "true";
>
>   errorArr[1] = "Name";
>
>   if (nameVal.length > 0 ) {
>
>     if (!check.test(nameVal)) {
>
>        errorArr[4] = '- may only contain alphanumeric characters, space (
> ), dashes (-), and underscores (_).';
>
>        if (nameVal.length > 50) {
>
>          errorArr[4] = '- must be less than 50 characters in length.';
>
>        }
>
>        msg += build_error_string(errorArr);
>
>     }
>
>   } else {
>
>        errorArr[2] = '- is Required.  Please specify a value and try
> again.';
>
>        msg += build_error_string(errorArr);
>
>   }
>
>   return msg;
>
> }
>
>
>
> With that out of the way, we now know that a leading and trailing space is
> not possible, which also rules out a name with solely spaces in the name
> (thank goodness!).
>
>
>
>   A-Z
>
> + 0-9
>
> + " " (Space)
>
> + _ (Underscore)
>
> + - (Dash)
>
> ------------------------------
>
> 39 characters
>
>
>
> The total 2 digit possibles with 39 characters is 39^2 = 1,521.  And if we
> take out the patterns with leading/trailing spaces, we lose 77 patterns and
> are left with 1,444.
>
>
>
> But come on, who wants to name their partitions a meaningless "-_" (dash
> underscore)?  So, we're looking at a realistic naming convention of A9 to
> 99 (if A-Z0-9), then we have 1,296 realistically possible names.
>
>
>
> On Mon, Apr 20, 2015 at 11:48 AM Lelio Fulgenzi <lelio at uoguelph.ca> wrote:
>
>  That's for two character partition names. My example was three character
> partition names. With two character partition names (assuming no case
> sensitivity) you get 36x36=1296 partition name combinations. I don't think
> that's enough.
>
>
>
>
>
> ---
> Lelio Fulgenzi, B.A.
> Senior Analyst, Network Infrastructure
> Computing and Communications Services (CCS)
> University of Guelph
>
> 519‐824‐4120 Ext 56354
> lelio at uoguelph.ca
> www.uoguelph.ca/ccs
> Room 037, Animal Science and Nutrition Building
> Guelph, Ontario, N1G 2W1
>
>
>
>
>
>
>
> itevomcid
>
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