Storage Area Network (SAN)

This is simple jot down of things related to Storage Area Network, some specific to HP's EVA 4400.

Components:

EVA – Enterprise Virtual Array
LUN – Logical Unit Number
HSV Controllers – Hierarchial Storage Virtualization Controllers (like VCS & XCS)
LS – Loop Switches
DAE – Disk Array Enclosures (Chassis)
DDE – Disk Drive Enclosures
EPB – Enhanced Port Bypass mode
PDU – Power Distribution Unit
PDM – Power Distribution Models
EAB – Enclosure Address Bus
EMU – Environmental Monitoring Unit
SMS – Storage Management Server
SSSU – Storage System Scripting Utility
EVA Perf – EVA Perfromance Monitoring
42U Rack – is a usual Rack with length of 42 RU. One RU (Rack Unit) or “U-Space” is unit for measuring length of a Server Rack. 1 U = 1.75inches (4.45 cm)

iLO – integrated Lights Out.
Controller contains – Control cache, Read cache, Write cache, Mirror cache

Softwares:

CA EVA – Continuous Access Enterprise Virtual Array (remote replication)
BC – Business Copy (local replication)
RSM – Replication Solution Manager (has GUI to manage CA, BC & features)
VCS – Virtual Controller Software
XCS – Xtensible Controller Software
Code Load – Controller Firmware

Concepts:

Has a pair of HSV Controllers to maintain redundancy at Controller level
Minimum of 8 physical disks are required for creating LUNs (constitutes one Disk Group)
SAN is called of configuration nCmD – n controllers, m Disks. eg. 2C4D = A SAN of 2 Controllers & 4 Disks
1 EMU for each DAE
SNS gives WWN to hosts
Snapshot – point-in-time backup, not continuous I/O. It is always delta data.
Snapclone – Continuous I/O. So, overhead. But is a exact replica. Can be presented as Vdisk.
Mirrorclone – It is at Container level. HP is getting rid of it.
Container – Space has to be specified while creating. This is not used for categorization
Folder – Space need not be specified while creating. This is used for categorization
Data replication is done at Container-level or Vdisk level.
For Mirrorclone, Container is a mandatory. But this concept is slowly going away from market.
Snapclone is a better solution.
EVA Backup is not possible with Command View EVA. Need to use SSSU.
Max LUN size is 2TB, min is 1GB.
Failover – Switches from A to B controller.
Failback – Switches back from B to A once A is alive again.

Options in LUN configuration:

Write Back – Acknowledges after writing to Controller Cache
Write Through – Acknowledges only after writing to hard disk
LUN Mapping – Visible, presented to Host
LUN Masking – Hidden, not presented to Host


Facts:

Battery life – 4 yrs expectancy
Customer cannot Code Load. It has to be with HP's support only.

Features:

One can install OS on one of the LUNs & boot all servers from SAN
Applications can be installed on SAN and servers can start applications from SAN

FC Switch:

Topologies: FC – AL (Arbitrated Loop), FC – SW, FC – P2P
Port types: N_port – on the host
F_port – on the FC Switch
E_port – port for linking to FC-Switches
EX_port – on the FC-Router
U_port – Universal Port


HBA – Host Bus Adapters
WWN – World Wide Network
WWNN – World Wide Node Number (This is the FC Switch number)
WWPN – World Wide Port Number (Port numbers on the FC Switch)

FC – Fibre Channel
FCP – Fibre Channel Protocol
FCIP – Fibre Channel Over IP
iFCP – internet Fibre Channel Protocol

Misc:

MPR – Multi-Protocol Router

IB – InfiniBand (faster speeds than FC)

Binary Prefixes

We know of kilobytes, megabytes, gigabytes, terabytes, etc.
In SI units, kilo represents 1000 (=10 power 3), whereas in computer world, it represents 1024, mega represents 1000000 (= 10 power 6) whereas in computer world it represents 1048567. This created ambiguity in their usage and practices. To get rid of this ambiguity, Binary prefixes, were created.

kilobinary = kibi
megabinary = mebi
gigabinary = gibi
terabinary = tebi and so on.

So, with this adoption these units were rewritten as kibibytes, mebibytes, gibibytes, tebibytes, etc. Similarly, the new representation exists for bits viz., kibibits, mebibits, gibibits, tebibits, etc.
This way, kilobytes, megabytes are supposed to be used as their SI counterparts representing 1000 bytes and 1000000 bytes.

Google SideWiki

Its one more 'provide-your-comments' application from Google. Sounds interesting but as pointed out by many, it may be another way of adding stuff about stuff on web.

Webmasters do NOT have an option to enable / disable this feature for their website, as of now. So, people can misuse to generate spam or write nonsense about a website and give a wrong impression. This becomes more dangerous because if you have a SideWiki enabled browser, comments are available right-away (if any, ofcourse) when you visit a webpage. One consolation is claiming a website on Google Webmasters Tools and projecting comments on SideWiki as Owner. This way, owners' comments will always appear at the top of others' comments on SideWiki.

As of now, it does not provide feeds which can be trapped and fed. But its possible to publish on Blogger and also to Share (after commenting) on Twitter, Facebook, etc. People are using round-about-way to create its feeds by publishing on a new invisible blog and taking feeds from that blog.

A con for its usage is, every webpage takes longer time to show up. The browser (I was using FF3.5.5 GTB6. GTB stands for Google Toolbar) hangs for good 3-5 secs. I disabled SideWiki, and it works fine.

Add GBookmarks, GTranslate, etc. in GReader's Send-to option

Google Reader has got an option to Send to under a feed, in August, 2009. With this, one can share a particular post on any of the popular sites which many of the Sharing buttons give. A good thing is that they have provided an option to add custom Send-to options under Settings.

One can add Google Bookmarks to these sets of options by adding the following code:
Name: Google Bookmarks (or anything of your choice)
URL: http://www.google.com/bookmarks/mark?op=edit&output=popup&b
Icon URL: http://www.google.com/favicon.ico

To add Google Translate:
Name: Autotranslate
URL: http://translate.google.com/translate?u=${url}
Icon URL: http://translate.google.com/favicon.ico

To add Add-to-any:
Name: Add to any
URL: http://www.addtoany.com/share_save?linkurl=${url}&linkname=${title}
Icon URL: http://www.addtoany.com/favicon.ico

It would be fun to get / add as many links to Send-to as needed.

Site Identity Button

We observe favicon for a site and with new firefox, even some text next to it. Firefox calls it Site Identity Button. It has three levels each with a different color:

• Grey: No information from site
• Blue: The connection is secure
• Green: Not only the connection is secure but it also comes with the owners information

Thin Clients

My new fascination is Thin Client Systems. Read about it only today and tell you, the number and kind of advantages it gives are numerous, specifically so in the area of maintenance. The below pps gives very precise and to-the-point FAQs.

Need to study the traffic that it will generate on the network. If that goes fine and 1GBps of network bandwidth safices the need, then we are on a go! :)



If you wish to download this pps as ppt or pdf, click on the Open in a new window icon in the menubar of the presentation. It will open up in a new window where you will be able to do multiple things with the presentation. In any case, this is the direct link to new window

Screens of Death

Screens of death are of different color, like Yellow, Red, Black, Green, Purple, Blue, etc.

Some of the applications have improved. They display images like Sad Mac, Google Chrome Sad tab, etc.

OpenID

Now a days, we see OpenID on so many websites. Wanted to know what this concept was about.

In simple terms, OpenID is a Universal ID (specifically a URL) which once created, can be used on an OpenID complaint website for a specific activity. For eg. on Blogger (OpenID compliant website), one can comment (specific activity) using an OpenID. One need not create a separate OpenID if one already has a Gmail id (or Google Accounts ID), Yahoo id, a blog on Blogger, etc. Best part about OpenID is that it is not dependent on any single OpenID provider. One can switch to any OpenID provider as one wishes, without monopoly of any specific company. It is an open standard with decentralized server.

So, next thing to know is which all are the OpenID providers. The list is here as well as here.

I wanted to use Gmail as an OpenID. To create an OpenID URL for Google Account ID or Gmail ID go here [SOURCE]. To use your Blog URL as an OpenID, details are given here.

Know how to run your own OpenID here.

Go here to get to know about having your own OpenID.

More on OpenID:

Spread OpenID

OpenID Foundation

QR Code & Microsoft Tags

Heard about QR codes (QR stands for Quick Response) today at this post on Google Docs Blog. QR Code is another way of storing information, like Bar Code, through 2-D images developed and popularly used in Japan.

One can create an image like the one shown aside. This image is for this very blog.There are QR Readers available (most of the phones now a days are coming with QR Reader embedded). When the reader scans this QR Code on their cell phone (with GPRS enabled), it will get one to this blog.





The fields & patterns correspond and convey a particular information. The image beside gives some insight into it.

Wiki has got all the information in short and crisp fashion, worth a read.

One can create this code by using Google API.

URL for creating code for this blog was: http://chart.apis.google.com/chart?chs=250x250&cht=qr&chl=http://robadilavoro.blogspot.com/

Change the url and have yours! :)

This template is the QR Code Gadget template available in Google docs. They say

Make a QR code of your data. Just put in the data and instantly a QR code is created matching a comma separated list of your data.

Surely worth a try.
-----------------------------------------------------------------------
Microsoft has got a similar one called Microsoft Tags


Signup, Create Tags and share them. Need not worry if you dont have a Windows Live login id. One can Signup with Gmail Id as Windows Live ID and use it for all future purposes.

The Tag created for this blog by Microsoft Tag looks like the one shown aside





If these were not enough, Wiki gives a list of other types of codes existing. The list is as below:

• Aztec Code
• Barcode
• Data Matrix
• E-Reader
• CueCat
• High Capacity Color Barcode
• PDF417
• Semacode
• ShotCode

ATI Catalyst (CCC)

ATI Catalyst alias Catalyst Control Center (CCC) is a front end to tweak the hardware functions like monitor settings, 3D settings, etc.
Similarly, Intel too has Intel Graphics Media Accelerator (GMA) Driver [FROM INTEL] which gives options to tweak the settings thru a GUI.

Google Waves Web Elements & Showcases Fusion

New announcements from Google:

• Google Web Elements: http://www.google.com/webelements/ 
• Google Showcase: http://www.google.com/help/ig/showcase/ 
• Google Fusion: http://tables.googlelabs.com/ Manage Online Database with collaborative tools of chatting, sharing, tracking changes, etc. FAQs 
• Google Translation Toolkit: http://translate.google.com/toolkit/ FAQs 
• The Next Big Thing from Google - Google Wave: http://wave.google.com/ 

Password encryption: Salt & Nonce

Salt Cryptography and Cryptography Nonce (Nonce: number used once) are added layers of security while storing passwords (Salt) and transacting passwords to-&-fro between the client and server (Nonce). A good read at Wiki.

Sharing Content

RSS feeds is the most common way of sharing content on web. Almost all the blogs and relevant websites have this enabled. With RSS feed agregators, one can subscribe and be upto date.

With the popularization of Socializing websites, one wants to share what one reads or likes with his/her friends on social networks (like facebook, stumble, digg, tweet, etc.) or email it to them. Thats when the concept of sharing using button came up and became popular.

One can give these options to the readers as text (using FeedBurner), or as button (using Tell-A-Friend or Add-this). They add themselves up at the bottom of each post (in blogs) or can be placed according to one's own wish.

These utilities give added features of multiple ways of subscribing, sharing and analysing the traffic/crowd that is visiting the site.

IM commands for FriendFeed

@me text - post to your feed
@room text - post to room
@room - list entries in room
@N text - comment on entry N
@user - list entries in user's feed
like N - like entry N
pause - Pause notifications
resume - Resume notifications
list - List recent entries

These are some of the commands that we can use in GTalk / GChat to post to FriendFeed.


Here is the complete list

Greasemonkey

I am sure many of us heard a lot about the terminology Greasemonkey but did not understand what it is all about.

Greasemonkey is an add-on onto Firefox. There are reports of it working even on Opera, Safari, IE to limited extent though. This is the master add-on which is like a container for all the 'User-scripts' which gets installed into Greasemonkey.
User-scripts are javascripts (extended-AJAX too) created to customize look, feel and functionalities of a webpage.
There are thousands of existing User-scripts available at the official website of User-scripts
Greasespot is Greasemonkey's homepage

Popular list of user-scripts:
by online-tech-tips
by Firefox facts
by Life-hacker

Firefox Add-ons

Finally, this post has become a reality. I had mentioned in an earlier post that soon there would be a post on my favourite add-ons from firefox. There would surely be more than these, but currently these Add-ons are actively decorating my Firefox. In Firefox's own words:

"You spend more time online than on the road, but you probably think more about avoiding traffic than enjoying the best of the Web.

So, why not customize your Firefox for the things you really love to do? Take your browser from simple to spectacular.

Firefox add-ons are little extras that allow you to add a personal touch to your browser. Select your favorites from the categories to accessorize your Web!"

So, here is the list of 9 add-ons for firefox:

• Lock the Fox - password protect Firefox window
• Server Spy - know which brand of HTTP server runs a particular site
• Tamper Data - view and modify http/https headers and post parameters
• TestGen4Web - Record/Store/Play Firefox sessions
• FormFox - Displays the Form action
• Event Spy - can watch Javascript events as they occur
• Add n Edit Cookies - name conveys all
• Cache Status - Easy cache management
• Cookie Swap - Swap Cookies to log into multiple Gmail accounts
  

Hope you would find them useful, as much as I enjoyed in finding them and trying them out.

Update: Forgot to add one more add-on - PDF Convertor - convert any webpage into a pdf then and there.

Animated Favicons

Now a days, many sites are displaying animated favicons (like this site on Email trace). How do they do that? Its simple. Create an animated gif file but with the size of Favicon (i.e. 16px by 16px). Then rename this favicon.gif to favicon.ico (.ico is the extension for favicons). Firefox renders these animated favicons, but not IE. IE displays only the first frame

l337

We all know the SMS language (you = u, Great = Gr8, are = r, etc.). There is a similar language for internet users which is considered geeky.

"l33t sp34k" is the international internet language coined by script kiddies and trolls who like to clutter up message boards and chat rooms with their claims of being "l33t H4xX0r5".

After going through a ten minutes read, I could interpret the statement: 1337 $|o3/-\|< |=/-\57 3|\|0U9|-| u <'/-\|\| 937 /-\ |0T 0F \/\//-\7 |7 5/-\5, 7|-|3|\| U c/-\|\| F|9uR3 0u7 \/\//-\7 u |\/||553o|.

"Leet speak fast enough u can get a lot of u wat p sas, then U can figure wat u missed" (in Italics - I do not know whether I could interpret it correctly)

How could I understand by just going through that language for 10 mins. Here is the help. Short course, in points, below

• Think of the symbols as shapes: a 5 looks a bit like an S, as does a $
• Combine two or more symbols and numbers to make single letters, such as |= for F or |3 for B
• Pay attention to context. If you can't figure out the meaning of a symbol, try to guess its meaning based on the letters (symbols) around it.
• substitute letters for other letters, sounds or words like f = ph, cks = xx, s = z or r = are. Interpretation of 1337$p34|<3r is leetspeaker
• Flagrant misspellings: Some, such as "kewl" (for "cool") are phonetic replacements, while others such as "teh" (for "the), or "ownt" and "pwned" (for "owned") are just an inside joke :)
  
• New grammatical structures: the suffix "0rz" can be added to a word to make it plural or to add emphasis, as in "r0xx0rz" for "rocks," where "r0xx" would substitute for "rocks". Another common suffix is "3d," used to indicate the past tense such that "rocked" becomes "r0xx0r3d," as is "7h47 r0xx0r3d" ("that rocked")
• l337 includes chat abbreviations too: BTW ("by the way"), TTYL ("talk to you later"), and the ubiquitous LOL (generally meaning "laugh out loud")
• Expand your vocabulary. Though most of the "new" words in 1337 are simply misspellings of English words ("taht", for example, or "pwn"), some are actually new coinages, such as "nooblet"--this could be written, for example, as "n008137"--which denotes a "noobie," or the 'newguy' |\|3\/\/|3 (newb) someone new to 1337 or something else. The best way to learn the vocabulary is to read a lot of 1337.
• Adapt to inconsistency. Sometimes, you'll see people with 1337 "skillz," sometimes you'll see "5k1||5," and sometimes "$c1llz0r3d."
• cApItalizE at random. Random capitalization is arguably an integral part of 1337. Some writers employ a consistent method, such as capitalizing all letters except vowels or only ending letters, but many simply capitalize letters (where they are not replaced by symbols), whenever they want.

l337 Chart:

• Note:
  
  • The commas are added to separate symbols
  • The symbol | (Example: B = |3 ) is a "down-slash", or "pipe", and not a lower-case "L" or capital "i"
  • The symbol ` (Example: T = 7` ) is not a standard apostrophe, but is a "Grave Accent" and is found on the tilde (~) key
  • Also keep in mind that the use of /-/ for H for example, aren't used nearly as often as the normal letter in a quick conversation. To write an entire sentence this way would take three times as long, thus the quicker single symbol or letter substitutions are more often used.

• A = 4, /-\, @, ^, /\ , //-\\
• B = 8, ]3, ]8, |3, |8, ]]3, 13
• C = (, { , [[, <, €
• D = ), [}, |), |}, |>, [>, ]]), Ð
• E = 3, ii, €
• F = |=,(=, ]]=, ph
• G = 6, 9, (_>, [[6, &
• H = #, |-|, (-), )-(, }{, }-{, {-}, /-/, \-\, |~|, []-[], ]]-[[
• I = 1, !, |, ][, []
• J = _|, u|, ;_[], ;_[[
• K = |<, |{, ][<, ]]<, []<
• L = |,1, |_, []_, ][_, £
• M = /\/\, |\/|, [\/], (\/), /V\, []V[], \\\, (T), ^^, .\\, //., ][\\//][,
• N = /\/, |\|, (\), /|/, [\], {\}, ][\][, []\[], ~
• O = 0, (), [], <>, *, [[]]
• P = |D, |*, |>, []D, ][D
• Q = commas are necessary: (,) or 0, or O, or O\ or []\
• R = |2, |?, |-, ]]2 []2 ][2
• S = 5, $
• T = 7, +, ']', 7`, ~|~, -|-, '][', "|", †
• U = (_), |_|, \_\, /_/, \_/, []_[], ]_[, µ
• V = \/ , \\//
• W = \/\/, |/\|, [/\], (/\), VV, ///, \^/, \\/\//, 1/\/, \/1/, 1/1/
• X = ><, }{, )(, }[
• Y = '/, %, `/, \j , ``//, ¥, j
• Z = 2, z, 7_,`/_

Try an online l337 translator here.

Leet examples [(l337 3><4|\/||*!3$) - This one created using the above suggestions. Looks damn cool!]

In English: Whats up man? I am fine here....are you?

][ /\/ !33+: Wh47$ µp m4n? 1 4m ƒ1n3 h3r3....4r3 ¥0µ?


More on leet
Source

p.s: Had trouble with escape charactering the HTML on this page. l33+ troubles html :P

ID3 Tags

As my new system is getting ready for heavy burdening of the space it professes to bear, be it visuals or audio files, there was a need for classification of songs into their respective genres for easier retrieval. This lead to study on ID3 tags, finally.

What are ID3 tags?
ID3 stands for 'IDentify an MP3'. It is associated with MP3 format files to add 'textual / graphical' information. It contains metadata like name of the artist, track title, album, lyrics, year, track number and genre in the file, allowing that information to travel with the file. Here is the official Home page of ID3.

When it first came out, ID3v1, it had multiple limitations, few being, appearance of this data (tags) only at the end of the song, having 128-byte fixed size. Owing to these, there was an immediate need to come out with ID3v2 which became popular, and also was more useful.

Windows gives an option to edit these tags, but it is restricted. It allows certain fields sometimes, and many times not. So, there was a need for exclusive software to help in this front.

If any of you are thinking of adding up 'metadata' to your song's list, which goes into GBs then there are softwares that are available for simultaneous editing of multiple mp3 files. A few listed below:

STamp ID3-Tag Editor
ID3-TagIT

p.s: For all those who are interested in knowing some jargons in the field of audio editing, here is a short glossary.

SMS vs EMS vs MMS

All of us know about SMS - Short Messaging Services & MMS - Multimedia Messaging Services. But then there is one more less-known terminology EMS - Enhanced Messaging Services

EMS stands between SMS and MMS. With EMS one can send picture of a cake, birthday song melody and a text greeting from a EMS capable mobile to another EMS capable phone. With MMS, one can send not only picture of cake, but from a large sized image to a small movie.

More on this:

Messaging Services Fundamentals
About EMS
Google Search on EMS vs MMS


Mobile News:


Sony Ericsson comes out with R-series, T-series phones. Reviews here 
Also releases very stylish W980 walkman phone, an edge over W960. A complete look at here.