RAID Array Levels

By Justin Tanker 

There are many different types of RAID arrays and each particular setup has its own advantages, disadvantages and specialized uses. Any one of these levels may or may not be most appropriate for your system depending on how much data you need to store and how you plan to use that data. With that in mind, let's look at the most common RAID levels and the strengths and weakness of each configuration.

RAID 0

A RAID 0 setup splits data evenly among two or more hard drives. It does not allow for any parity information and therefore there is no data redundancy, which means that any disk failure will affect the entire system. The primary function of this specific design is to increase system performance.

Using a RAID 0 setup, you can only store as much data as allowed by the storage capacity of the smallest drive in your system. The more hard drives you use in this setup, the lower the reliability of the system, since the failure of one drive affects them all. The more drives you use, the more chance there is that something will go wrong and cause the entire system to fail.

RAID 1

A RAID 1 setup creates a mirror image or exact copy of a group of files on two or more disks. This array allows for redundancy, meaning that since the same data is stored on multiple drives so that if one drive fails, you can still retrieve the data from the other drive. With this type of system, unlike the above RAID 0, the more drives you have in your array the more reliable the system is. To lose all your data with a RAID 1, each and every drive in the system would have to fail - which is quite unlikely to happen at the same point in time.

However, like RAID 0, this system's storage capacity is again limited by the size of the smallest drive in the array. RAID 1 allows for better performance the more drives you have, since data can be read from more than one disk at a time.

RAID 2

RAID 2 uses a technique called striping, or allocating data among several hard drives at the bit level, as opposed to RAID 1 which creates the mirror image of whole blocks of data. This allows for extremely high rates of data transfer. This set up is now essentially obsolete due to the fact that all hard disks now have an error correction code that use similar technology to the RAID 2 without the added complexity.

RAID 3

Another obsolete and rarely used set up. It uses striping to allocate the data at the byte level, and designates a specific disk for storing parity information. One of the main deficiencies of RAID 3 is that it can't handle multiple requests for data simultaneously, which slows its performance compared to other set ups, like the RAID 1.

RAID 4

RAID 4 uses block level striping along with a dedicated parity drive. Each drive in the system can work independently and in most cases can handle multiple requests for data simultaneously. This set up requires a minimum of three hard drives for its configuration to work. With RAID 4, a substantial load is placed on the parity drive and it often becomes a bottleneck for the entire system. For this reason, the performance level of this type of array can be rather poor.

RAID 5

RAID 5 uses block level striping and distributes parity data among every drive in the array. This is a very popular configuration since it allows for greater data redundancy while still offering a high level of performance. RAID 5 implementation requires a minimum of 3 hard drives in the system, but, in theory, you could have an unlimited number of drives connected to the system.

RAID 5 can survive the failure of a drive in the system by using the parity and data blocks from the surviving disks to reconstruct the lost data while the system continues to run, and this feature is known as Interim Data Recovery Mode. The operating system notifies the administrator that a drive needs to be replaced while continuing to run without any disruptions, though the systems performance will be somewhat slower due to the changed operation.

RAID 6

RAID 6 is an extension of RAID 5 that adds an additional parity block on each drive. This allows for continued performance in the event of two simultaneous drive failures.

There are several other non-standard RAID levels such as RAID 1.5, 7, 5E, 5EE, 6E and others, but these are more complicated and less common versions. The most popular levels of RAID today are RAID 0, 5 and 6. Having a RAID array in place can help to secure your data and protect it from loss in the event that you have a hardware or software problem. Article Source: http://EzineArticles.com/?expert=Justin_Tanker

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RAID Data Storage Explained

By Justin Tanker 

RAID data storage is a very commonly used technique for maintaining and accessing large amounts of information. Most RAID applications are used on computer servers, though there are some levels that can be used for desktop applications as well.

In this article we'll look at what exactly RAID is, what it does and the advantages and disadvantages of using this technology.

What is RAID?

RAID is an acronym for Redundant Array of Independent Disks. The technique was invented in the late 1980s and continues to be used today. In essence, RAID is a way for multiple disk drives to work together and present themselves to an operating system as a single data storage medium.

RAID has essentially three goals, to improve the performance capability of a computer or server, to increase the storage capacity of said computer and to improve the reliability of the data stored on it.

Different levels of RAID accomplish these three goals to a greater or lesser degree depending on the storage technique that is used.

RAID Techniques

RAID uses a couple of basic data storage techniques to achieve its goals. The three basic data storage techniques are mirroring, striping, and parity.

Mirroring is the process of making an identical copy of a set of data and storing it on more than one disk. This provides data redundancy, which protects your data by making it possible to retrieve the information from a different drive in your system if the original hard drive fails for some reason.

Striping is the process of allocating data among various drives in the system. Striping evenly distributes data on each of the drives which allows you to access the information more quickly.

Parity is a technique that allows you to reconstruct blocks of data in the event of a drive failure. Each level of RAID uses these techniques in different ways to achieve the common goal of increased capacity, speed and reliability.

RAID levels

There are many different levels of RAID. The levels differ in the way that they store and process data and are not to be considered sequential in performance ability. For example, RAID 5 is not necessarily better than RAID 1, nor is RAID 100 better than RAID 50. The most commonly used levels today are RAID 0, 1, 5 and 6 along with the nested levels 10, 50, 51 and 60. (We'll get to nested levels shortly).

There are seven standard levels of RAID, 0 through 6. Levels 2, 3 and 4 are now considered obsolete. In addition to these standard levels, there is quite a variety of non-standard and nested levels. Non standard configurations include levels such as 7, 5E, 5EE and other exotic combination's. Nested levels combine two of the standard levels to form the nested level.

For example, level 10 is a combination of levels 1 and 0. For practical purposes, the array is designed as two separate RAID 1 arrays that communicate with the system and each other as if they were individual drives in a RAID 0 array. This allows you to combine some of the advantages of level 1 with the advantages of level 0, producing a more powerful and flexible array.

Each level has its own strengths and weaknesses. As a general rule, RAID 0 has the best performance and data storage capability of any of the other arrays, however it provides no fault tolerance, so if any drive in the system fails for any reason, you would lose all of your data. For this reason, RAID 0 systems are often combined with other levels such as RAID 10, 50 or 60 to combine the performance advantages of RAID 0 with the data reliability of the other levels.

RAID 1 and 10 both provide high levels of performance and data reliability, but their storage capacity is relatively low. RAID 5 and 50 are great for reading data, but relatively slow in writing new data to the drives. It has excellent storage capacity and is a relatively inexpensive option compared to some of the other levels. RAID 5 tends to be the most popular RAID level available.

RAID 6 and 60 provide the best data protection ability and excellent read performance, though the write performance is relatively slow. RAID 60 tends to be among the most expensive of RAID options.

There is no one best RAID level for everyone. The best solution depends on your needs for storage capacity, data protection and performance in both reading and writing data to the drive.

If you're unsure as to what level is best for you, consult a your local computer service provider or data recovery specialist. Article Source: http://EzineArticles.com/?expert=Justin_Tanker

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Five Reasons Your Business Needs Offsite Data Storage

By Brandon Medley
With the recent economic downturn businesses may question whether they can afford to take extra precautions when it comes to the security of their business data. The truth is that businesses really can not afford not to take extra security measures. It is important to regularly back up business data, save your information to portable files, like onto disc, install anti-virus software and even have your business data protected at an offsite data storage facility.

System Crashes

Computers were designed to help make our work easier and faster, but this is not to say that computers aren't subject to problems of their own. Systems are known to crash and your business data can be lost in an instant. This is why it is vital that you continually back up your data. Make sure you save it to disc or another portable storage systems, rather than just relying on the hard drive. Better still, make use of an offsite backup service so that no matter what happens to your computers within your office you do not lose your business data.

Accidental Error

You need to make allowances for human error as it is not uncommon for accidental error when using computers. An employee may forget to save documents or fail to back them up. They could accidentally open an email from an unknown source and unleash a virus on your entire network. As well as training staff to save business data adequately make sure they know your policy on anti-virus software and that they apply it. As an extra measure of security cover yourself by having business data stored offsite.

Viruses

Viruses can take down individual computers as well as infect your entire computer network. With lost data being so hard to recover it is important that you protect yourself from viruses with anti-virus software as well as anti-spyware. Having this software applied to all computers via a centralised system is a good idea, that way your employees don't have to worry about it and it is not likely to be forgotten. Make sure it is updated regularly. Storing data offsite for added backup is an extremely good idea, that way if your computers fall foul of a virus you have not lost all your data.

Theft

Theft is something that you don't think will happen to you but it can. Thieves are most likely to be targeting equipment itself, rather than the data stored within it, but although you can easily replace the computers replacing the data within them is not so easy. As well as saving data to the hard drive make sure you save to portable discs or a memory stick. In case of theft storing your data offsite is a wise idea.

Natural Disasters

This is another case where you always assume this will never happen to you, but it can and it does. Take for example the recent floods in Queensland and the flash flooding they experienced. Damage to computers by floods, earthquakes, cyclones or fire does happen, and even though you can insure equipment and buildings and have them replaced, you can lose your data forever. Increase your chances of retrieving data by storing it offsite.

By the way, do you want to learn more about Computers and Technology? If so, I suggest you check Offsite Backup Service and Offsite Data Storage.

Article Source: http://EzineArticles.com/?expert=Brandon_Medley

Alma Public Directory

The Five Best Ways to Secure Your Business Data

By Brandon Medley 

Protecting your business data is vital. If you were to lose business information from your computers it could potentially cost your business thousands, not to mention the hours it would take to replace it. Some of your data may even be irreplaceable, so you need to regularly back up your data or think about having an offsite backup service.

Save your data

While you are working make sure you constantly save your data. If there is a sudden power failure then you won't lose what it is your have been working on. It is also a good idea to save your information to other areas as well as the hard drive. Save your data to either a USB or a disc. You may even want to print out hard copies of your data and file it.

Passwords and firewalls

Protect your files with passwords so that your business information can only be accessed by those who are authorised to. Passwords are necessary for sensitive information, particularly if the privacy of your clients and staff could be comprised if your business data is accessed. When choosing a password don't pick something that is too obvious, for example don't use your birth date or nick name, but instead choose a mix of characters and numbers. Also don't write it down and leave it somewhere where it can be easily found. Another good idea is to install a firewall and make sure that you update it regularly.

Back up your data

Don't forget to back up your business data and remember to do it often. As well as individual computers ensure that the server is backed up as well. For extra security you may want to look at having an offsite backup service. Be prepared for worst case scenarios, such as power failure or damage to your computers and software through natural disasters, like water damage from floods or cyclones.

Virus protection

Make sure that you protect your computer's security with virus protection. A virus can affect your computer, or even the whole network, before you even realise. People can easily download something that is carrying a virus and very quickly your business data is compromised. Develop a computer security policy and have your anti-virus and anti-spyware management systems centralised instead of everyone having to be responsible for their own computer. This way you can be sure your system is protected. Scan for viruses frequently and make sure you are given automatic updates.

Train employees

Make sure you keep employees up to date with your computer security systems. If you have a password policy let them know about it, or if you have installed new anti-virus software then let them know, and train them if they need to apply it themselves. Ensure that all staff are aware of how important the security of your business data is and that they know how to back up data and use the anti-virus software. Make sure your employees are trustworthy too. Having them sign a confidentiality agreement when they start working for you can be a good idea.

By the way, do you want to learn more about Computers and Technology? If so, I suggest you check Offsite Backup Service and Offsite Data Storage. Article Source: http://EzineArticles.com/?expert=Brandon_Medley

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Criteria For a Workstation Lock-Down Solution

By Terry Mayfield

Network security has become a big issue. Some companies spend big money on server management while the workstation management becomes less a priority. Thorough network security requires that all possible sources of a breach be secured. This article offers criteria for securing (locking down) all the workstations on the network.

What does it mean to lock-down a workstation? For our purposes a network workstation is locked down when it is configured to prevent unauthorized installation and execution of a software application.

Who establishes security polices from which the lock-down criteria comes? Network security is as much a business concern as it is an IT concern. Why? Because data security and business continuity are part of a bigger concern: risk management. Today, government regulations mandate data security, and hold companies accountable for security breaches. The management of the organization is responsible for drafting the security polices within the context of legal and business requirements.

The IT department is then tasked with the job of determining how to implement the network security policies. They determine what a proper configuration of the workstations will be. That configuration would include applications that are compatible with each other and meet the business needs of the company. The configuration would also include necessary hardware drivers and system services.

Here are five criteria that might be helpful in evaluating a workstation lock-down solution. The solution should:

1. Have Flexibility.

A company's data network is not static. As business needs change, software requirements will likely also change. A workstation lock-down solution needs to be flexible enough that it can be easily configured to support new applications and patches for new versions of existing applications.

2. Have Adaptability.

It should adapt to new security policies, procedures, or workflow requirements. The admin interface should be simple and adaptable enough to support ad hoc requests.

3. Be Secure.

The solution should enforce restrictions without being vulnerable to unauthorized changes, or overrides, or workarounds by end users. The solution should work regardless of path changes, file renames, or file modifications by a user.

4. Have an easy-to-navigate Admin Interface.

The admin interface should be able to analyze files across the network, catalog those files, and generate notifications regarding their status and location.

5. Be Automated.

Any solution will require some initial configuration. Decisions will need to be made as to which programs should and should not be restricted. Once the approved software configuration has been set up, the software should automatically monitor the network. Any new unauthorized software that is detected should automatically be restricted and brought to the IT staff's attention for action.

Terry Mayfield is a Business Continuity expert with 19 years experience in the field. Mr. Mayfield has worked in the telecommunications industry during a period of innovation and rapidly changing technologies, and has helped his clients evaluate potential data loss threats and formulate data protection and recovery strategies. He is available by phone (205-290-8424) or email (terrym@askbts.com) to discuss your data protection requirements and review your network storage issues. To Download the Free Advisory Guide "What Every Business Must Know About Protecting And Preserving Their Critical Data" go to http://www.gosleepez.com. Article Source: http://EzineArticles.com/?expert=Terry_Mayfield

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Backing Up Your Computer

By Jama St. John

As a business owner, there are many things that need to be done on a regular basis to protect your investment. Backing up your computer on a consistent basis is important to keeping your data intact. There are many ways we could lose information on our computer: a power surge, natural hazards like lightning or tornadoes, fire, unnatural hazards like viruses, and just plain old equipment failure. We don't like to think about it, but any of those are possible at the most inopportune moment!!

First, let's start with what to backup. You can do full operating system backups or just backup certain information. Here's a list of some of the specific things you might not have thought of:

- Documents.

- Bank records and other financial information.

- Digital pictures.

- Software and music purchased and downloaded through the Internet.

- E-mail address book.

- E-mails.

- Outlook calendar.

- Internet Explorer "Favorites".

- And most important, anything you cannot replace if your computer crashed.

Next, how often should you backup? This really depends on your personal use of your computer and what information you store on it. For example, I have done a backup of my entire system using Maxtor's One Touch II external hard drive, and I will do this monthly... possibly more often if I've installed a new program or made several changes to my computer. But in addition to my entire system backup, I also have a backup of my digital pictures onto a DVD-RW for permanent storage. And I backup my Outlook address book and emails, QuickBooks files, My Documents, and Internet Explorer Favorites weekly onto a DVD-RW.

Now, where to store your backup? First, there are several offsite backup storage services on the Internet. Google "offsite backup" and you'll get endless choices. Most have some sort of monthly fee. When choosing an online storage company, you want to make sure that the service is not only reliable, but that the company is stable and will not unexpectedly go out of business and you can't get your backup. A positive to online storage is that your backup is stored away from your office or home. In the event of a natural disaster your backup would not be affected. A couple of cons are if the online service's servers go down, you won't have access to your files, the company's servers could be hacked and your information could get in the hands of someone you don't want it to get into, and the company could go out of business without warning. I personally do not use online storage, but several other virtual assistants have recommended Carbonite or Mozy. Whoever you choose, do your homework and consider not only using offsite storage but one or more of the following onsite storage.

As far as onsite backup, there are several options.

- CD/RW: Newer computers come with either a DVD or CD burner and pre-installed software. The CD/RW compact discs are rewritable, meaning you can use the same CD over and over. CD/R compact discs are not rewritable and can only be used one time. Compact discs hold up to 700 MB and are fairly inexpensive.

- DVD/RW: Newer computers come with a DVD/RW burner and pre-installed software, which will also burn CDs. A DVD can hold up to 8.5 GB and are still a fairly inexpensive way to backup.

Whether you choose a CD or DVD back up, organization is key. Make sure to label your discs and date them. If you're doing a major back up, you'll possibly need more than one disc to complete the backup.

- USB flash drive: This is a small hard drive about 2 or 3 inches long that plugs into a computer's USB port. You can download information directly onto the flash drive over and over. A search on http://www.amazon.com resulted in numerous flash drives, ranging from 512 MB up to 4 GB. If you choose to use the USB flash drive, be careful where you put it -- they're tiny!!

- External hard drive: This is a hard drive that is separate from your computer. It has its own electric source and you connect it to your computer via USB or FireWire. Storage sizes vary from 120 GB up to 500 GB and the one-time cost of purchasing the hard drive is more expensive than our other options. I personally use Maxtor's One Touch II for backing up my entire system. It creates historical backup versions with full system restore to a point in time, something that's unique to this way of backing up. It comes with its own software for backing up the system.

When using onsite storage, it's best if you have someplace offsite to store your backup. Perhaps take a copy home with you, as well as leaving a copy at the office. I have a separate storage building where I keep my backup. This way, if there's a fire or water gets into my office, my backup is still safe.

Okay. So you've decided what to backup, when to backup and what media you want to use, now, how do you do it? Well, to some degree this varies on which method you've chosen to backup to. But basically, if you're using Windows Vista or Windows XP Professional Edition, there is a backup utility you can use to do a partial or complete backup. If you're using Windows XP Home Edition, you'll have to install the backup utility from your Windows XP CD. If you're using an external hard drive backup, this will have its own backup software.

Now let's say you've gotten your entire computer backed up, but every now and then you want to back up your Outlook email messages. Here's how: Select "File," then "Import and Export". Select "Export to a file," then click next. Select "Personal folder file (.pst)," click next. Select which folder you want to copy. For example, the Inbox, including all subfolders. Click next. Then choose where you want to backup to. I personally save it to "My Documents".

And what about all those Favorites you've stored on Internet Explorer? Here's how you can save those to backup. Select "File," then "Import and Export". This will start the Import and Export Wizard. Select "Export Favorites," click next. Select "Favorites," click next. In the next window you can choose where you want to save your backup. Again, I personally save to "My Documents". Click Finish.

When I backup my QuickBooks weekly, I also back this up to "My Documents". When I download programs off the Internet, these are downloaded into a subfolder called "Downloads" located in "My Documents".

I put everything I can into "My Documents" because then weekly when I backup to a DVD, I only have to backup my "My Documents" folder. As I mentioned earlier, I also do a full system backup to the external hard drive monthly, at least.

Depending on how much data you're backing up, it can take a long time to finish, so be sure you're backing up when your computer will be on and you won't be using the computer. You can also set the computer to backup automatically.

Now you're loaded with knowledge to begin your ritual of backing up.

"Jama St. John of Gulf Coast Office Support publishes a biweekly e-newsletter with tips for office efficiency. To receive your subscription, go to http://www.gulfcoastos.com" Article Source: http://EzineArticles.com/?expert=Jama_St._John

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What Is Physical Drive Failure Recovery?

 

By Jennifer A Bell

The loss of business data, such as document, spreadsheets and statistics, causes a disruption of business and results in confusion, contention and profit loss. If the data is not recovered quickly, the result may not only be lost profit, but possible business closure. Therefore, it is imperative that a business has a plan for data recovery. The business owner should research all of the possibilities and have an effective plan for recovering from a data disaster. This should include securing the services of a reputable data recovery company.

By understanding the types of data loss and hard drive failure, the recovery method needed become apparent. Accidental deletion or file corruption cause logical drive failure; therefore, a software solution often resolves this problem. However, a physical drive failure causes loss that is more extensive and should be handled quickly and carefully. Only a drive repair and recovery service has the expertise and equipment to recover the lost data.

Clicking and grinding noises coming from the computer are signs of impending failure. The computer should be shut down immediately and the recovery service contacted. A hard drives that will not spin up or computers that will not boot are also indicators that physical drive failure has occurred. A good data technician can analyze the symptoms and recommend a course of action for recovery.

There are many causes for hard drive failure. Some causes are beyond human control, but others can be prevented by responsible operation.

• Overheating will cause failure of drive electronic components. A failed cooling fan should be replaced before using the computer.
• Electrical spikes and surges will damage both electrical and electronic components. A universal power supply with adequate surge suppression is a good investment.
• Using the computer will cause normal wear and tear on the drive. This is unavoidable, but the user should listen and watch for the warning signs of impending failure.
• Mishandling of the computer will result in premature drive failure. While laptops and notebooks are very susceptible to this kind of damage, desktop computer also suffer damage from improper handling. Moving the computer while it is running is a common cause of failure.
• Natural disasters are unpreventable, of course. However, a business owner should plan for data recovery in these situations as well.

Data recovery from physically failed drives is only be done effectively by a qualified data recovery service. Hard disk file recovery from physical failure requires special training and equipment. Qualified technicians will open the drive and replace defective components in a certified cleanroom. The cleanroom employs an air purifying system to remove dust and other contaminants that will cause further damage to the drive components and media. Furthermore, exact replacements are used for component repair.

TheDatarescuecenter - Professional data recovery services for all types of emergency data recovery and data migration services. We also provide NTFS file recovery services for specialized needs. Article Source: http://EzineArticles.com/?expert=Jennifer_A_Bell

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