dza + theory   14

Ricci Adams' Musictheory.net
Learn music theory! Notes, lessons, tools !
music  education  learn  learning  howto  tutorial  guide  theory 
april 2012 by dza
Does RAID 1 protect against corruption? - Super User
It depends on where the corruption stems from. If a drive in a RAID 1 mirror is screwey and is writing nonsense then the RAID mirror will degrade and the good drive will be in use and you'll have the good files. In the case of RAID 5 this is done with 2 data drives and a parity drive (in simplest form) and if one of the 3 drives is failing to write proper files then it will fail out and you'll be left with either 2 data drives or 1 data drive and a parity drive.

Now lets look at what happens if the corruption is caused by a virus or a bug in a program. In RAID 1 and RAID 5 no drive will be taken out of service because the drives are writing properly. Nothing has failed. However files will be destroyed because the virus or bug is writing junk, and it will write it to both your drives in a RAID 1 mirror, and to all 3 of your drives in a RAID 5 system.

That is why RAID is not backup. It prevents the most likely failure which is a disk failure but it doesn't account for a lot of other scenarios.

Conclusion:
If your data is eaten by a virus or accidentally deleted, the RAID can never distinguish it as good or bad. All the RAID is in charge of is making sure that (in a RAID 1) that both disks are equal. If a sector fails a checksum, the RAID controller compensates to repair it, or triggers a rebuild. In a RAID 5, if a sector fails a parity check, a rebuild is triggered. RAID protects the physical drives from failing, and resulting from data loss. They cannot protect against data lost to program faults or viruses.
raid1  raid  theory  mirroring  mirror  backup  data  integrity  corrupt  corruption 
december 2011 by dza
Understanding the Git Workflow
Some ways of WHY and HOW GIT can go wrong.

Very recommended reading for GIT newcommers.
git  github  scm  howto  guide  tutorial  help  cmd  cmds  commands  cmdline  source  sources  sourcecode  source-code  versioning  version  commit  push  pull  workflow  theory  dev 
september 2011 by dza
FBI, DoD, NSA: All Spying on You -- In These Times
Quietly, the war on terror, in which everything is permitted, has laid the ground work for the Bush administration to intrude into the political life of citizens.

Over the last several months, it has been revealed that the FBI, the Pentagon and the National Security Agency have each set up apparently independent covert operations to monitor the constitutionally protected political activities of citizens opposed to the Bush administration’s war in Iraq.

The Washington Post discovered that under authority granted by the U.S. Patriot Act, the FBI has been issuing what are known as “national Security letters” that allow the bureau to spy on U.S. residents. The November 6 Post reported, “The FBI has issued tens of thousands of national security letters, extending the bureau’s reach as never before into the telephone calls, correspondence and financial lives of ordinary Americans. Most of the U.S. residents and citizens whose records were screened, the FBI acknowledged, were not suspected of wrongdoing.”
security  nsa  nwo  conspiracy  theory  dod  fbi  bush 
july 2011 by dza
Dominator Culture
Wilhelm Reich called it the Emotional Plague, and Riane Eisler labelled it the Dominator Paradigm ("Dominator Culture").
It arises sometimes when a society is subjected to extreme and prolonged stress, for example, starvation, which causes a chronic activation of instinctual fight-flight-freeze instincts. This in turn results in depression, anger, suppression of free-flowing breathing and sexuality, and loss of full contact with reality. It is passed on to children by emotional abuse and indoctrination.
illuminati  nwo  new  world  order  conspiracy  theory  religion  politics  emotional  mind  plague  culture  psychedelic  psychedelics 
july 2011 by dza
New Memcached Extension for PHP – techPortal
The extension is for dealing with memcache from PHP, and is called memcached (not to be confused with the existing extension, “memcache”). The idea behind the new extension is to leverage the functionality contained libmemcached – a solution which has been widely adopted across many scripting communities and beyond. The extension is available in PECL and has lots of shiny new functionality. This article looks at how to obtain and work with the new extension, and also shows off a couple of the new features it includes.
web  webdev  webprogramming  php  memcached  memcache  cache  caching  optimize  optimization  code  tutorial  guide  howto  dev  programming  script  scripting  theory 
july 2009 by dza
Getting Started with Memcached – techPortal
Memcache is a tool which can cache objects in memory – and is often used for speeding up dynamic web applications. PHP has a built-in module for working with memcache, and its a simple and convenient way of introducing caching to your application.
web  webdev  webprogramming  php  memcached  memcache  cache  caching  optimize  optimization  code  tutorial  guide  howto  dev  programming  script  scripting  theory 
july 2009 by dza

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