No matter how much you trust your hosting company, disasters happen to everyone. You might also decide to change hosts, in which case you will need to migrate your website and database. In either case, you should have a full backup of your files from which you can easily restore, without losing any important data. By making regular website backups an organisation can always feel safe that it’s data will not be lost due to a virus attack or server failure.

There are two main approaches to web site backup: external, when software acts as an “exterior visitor” browsing the site – and internal, when you have access to the site’s contents. The first one suggests building a site map through visiting all links and copying all text and images from the web server. This method does not provide much accuracy and cannot be used to restore the site if it fails.

The second approach allows you to back up the whole website without exceptions and always be able to restore it in case of a disaster.

Backing up your website minimises the risk of data loss in case of a disaster and reduces downtime for your server. Time is money – the more your site is unavailable, the less profit you make. Furthermore, restoring a backup of your website to a different location is a very convenient way to make a clone of it.

Besides websites, many companies also exploit database management systems to store customer data and coordinate business activities. Without a recent back-up of these files, your website may not load, or be vacant of content.

Ensure your website files and database are backed-up from source files. To discuss any concerns, please call our experts on 0800 050 1128.

magic magic

A new manufacturing process that will put 640GB on a single HDD platter, has allowed manufacturers to dramatically increase storage capacities drastically. As the 3.5-inch drives used in desktop PCs typically hold four or five platters, that suggests a whopping 3.2TB hard disk space of storage on a single drive. Looking at the likely timing, the new manufacturing technology could put the giant drives in shops as early as February next year.

Manufacturers such as Western Digital, Samsung, TDK and Hitachi are all introducing 2TB+ drives and the other manufacturers will not be far behind. However if you are storing this amount of data, is a single HDD the answer? Given the well-documented manufacturing problems with many of the 1TB drives, should users be more cautious?

Well in our opinion the answer should be a resounding yes. New technology is always fraught with teething problems and it often takes several generations of media, before a reliable product is found. Although companies like Hitachi are spending large research budgets on developing this technology, the mean time before failure (mtbf) cannot be accurately calculated until the product has been on the market for a while and all failures carefully analysed by the manufacturer.

Given the minute tolerances within a HDD and the associated heat dissipation issues, my advice would be to stick with lower capacities for the time being and even RAID them together for added security. RAID data recovery is always a possibility if the RAID drive fails.  Hitachi still remain at the top of our list of the most reliable manufacturer, but I would sit tight until the new technology is proven.

Hard disks are mechanical devices with moving parts, and as such will break down eventually, compromising any data stored on them that is not backed up. External drives are likely to break down much quicker. One technology that was developed to deal specifically with this issue and deal with this is a RAID data recovery drive (Redundant Array of Inexpensive Disks).

The common factor that all RAID levels share, is the use of a RAID controller that intercepts data intended for storage on the logical hard drive. This data is then either duplicated by the controller for storage on multiple drives in the array at once (’mirroring’), or broken down into smaller chunks which are then divided between the available drives in the RAID array (’striping’).

Setting up RAID on your PC could not be easier. RAID is managed through Windows XP’s disk management window, found by right clicking on ‘my computer,’ then selecting ‘manage’ followed by ‘disk management.’ Windows XP Professional is only capable of creating RAID 0 striped arrays, while the various Windows Server operating systems can also create software RAID 1 mirror arrays. Alternatively, RAID can be purchased as an external unit, such as in NAS (Network Attached Storage). RAID 0 data recovery is possible despite the fact that it does not contain mirrored drives.

RAID is a much safer option for your data, as opposed to external hard drives, which have a very high failure rate. The access speeds are much greater with RAID, yet the price is equivalent. We would advise that external hard drives are only really useful for transporting data, or as backup devices.

Drive failures frequently are correlated and if you absolutely don’t want to lose your data, RAID 6 is the safer of the two options. There’s always the possibility that a second drive will fail during the build of the hot spare process.

Other things to think about are the size of the array. If your RAID array is over a TB then RAID 6 is definitely a better choice because of the long rebuilding process. Also what if an unrecoverable read error occurs while the hot spare is rebuilding, in a RAID 6 environment the second set of parity can be used to continue rebuilding.

What about RAID level 10 to be absolutely sure of safeguarding your data? RAID 10 mirrors everything, therefore an array requires double the disk capacity of the data to be stored. The remainder of the capacity constitutes the mirror.

If a RAID 6 array comprises four disks, only 50% of that space is available as usable capacity, but the proportion of usable space increases as you add more drives. That means half the total capacity of a RAID 10 array will always be dedicated to protection, but with a RAID 6 array the usable capacity grows as the number of drives increases. For example, if you increased the number of disks in a RAID 6 array from four to eight, the space consumed by parity data would decrease from 50% to 25%.

RAID 10 has among the fastest rebuild times possible because it only has to copy from the surviving mirror to rebuild a drive, which can take as little as 30 minutes for drives of approximately 1 TB. The key drawback of RAID 6 is that the time it takes to rebuild the array after a disk failure is lengthy because of the parity calculations required, often up to 24 hours with even a medium-sized array.

RAID 10 doesn’t need special hardware. Most controller hardware will support RAID 10 with good performance. Because RAID 6 doubles the parity calculations for every write, it requires specially designed controller hardware.

Many storage managers have a hard time deciding which redundant array of independent disks level to use for the best availability and reliability. If you are undecided on RAID 1 or 5, consider RAID 1+0 or 6!

RAID Levels

The Thecus N4100+ supports standard RAID levels 0, 1, 5, and JBOD. You choose
a RAID level when you create a system volume. The factors for selecting a RAID
level are:

• Your requirements for performance
• Your need for data security
• Number of hard disk drives in the system, capacity of hard disk drives in
• Will you be required to perform a RAID data recovery

the system

The following is a description of each RAID level:

RAID 0
RAID 0 is best suited for applications that need high bandwidth but do not require
a high level of data security. The RAID 0 level provides the best performance of
all the RAID levels, but it does not provide data redundancy.
RAID 0 uses disk striping and breaking up data into blocks to write across all hard
drives in the volume. The system can then use multiple hard drives for faster
read and write. The stripe size parameter that was set when the RAID was
created determines the size of each block. No parity calculations complicate the
write operation.

RAID 1

RAID 1 mirrors all data from one hard disk drive to a second one hard disk drive,
thus providing complete data redundancy. However, the cost of data storage
capacity is doubled.This is excellent for complete data security.

RAID 5

RAID 5 offers data security and good performance. It is best suited for networks
that perform many small I/O transactions at the same time, as well as
applications that require data security such as office automation and online
customer service. Use it also for applications with high read requests but low
write requests.

RAID 5 includes disk striping at the byte level and parity information is written to
several hard disk drives. If a hard disk fails the system uses parity stored on each
of the other hard disks to recreate all missing information.

JBOD

Although a concatenation of disks (also called JBOD, or “Just a Bunch of Disks”) is
not one of the numbered RAID levels, it is a popular method for combining
multiple physical disk drives into a single virtual one. As the name implies, disks
are merely concatenated together, end to beginning, so they appear to be a
single large disk.As the data on JBOD is not protected, one drive failure could result total data loss.

Stripe Size

The length of the data segments being written across multiple hard disks. Data is
written in stripes across the multiple hard disks of a RAID. Since multiple disks
are accessed at the same time, disk striping enhances performance. The stripes
can vary in size.

What is RAID?

RAID stands for “redundant array of independent disks” and is a computing system that uses multiple hard drives to share data or replicate it across the drive network. The benefits of using a RAID system include increased integrity of data, capacity, and fault-tolerance in comparison to other computer systems. The key component in the early days of RAID was to use older technology to combine into a system that would prove to be very valuable in terms of information technology.

The array would offer greater speed, reliability, capacity, and any combination of those and would end up being significantly less expensive than any of the newer hardware on the market because it coupled multiple devices that would have a greater advantage over the single newer devices. RAID, simply, combines multiple hard drives into one single unit.

Reliability of RAID

RAID is one of the most reliable systems of information technology that you can create because of the backup of having multiple machines storing the information. Having information replicated on multiple hard drives is advantageous because that information is copied and stored in more places than an average user would find. RAID data recovery, therefore, is something that most users knowledgeable of the RAID system can do but there are cases in which that is not possible.

RAID configurations are reliable but they also have a general language of data loss in case this should happen. A “failure rate” is the rate at which a hard drive is faster or slower than its adjacent hard drives. “Mean time to data loss or MTTDL” is the time in which there is data loss in a given array. “Mean time to recovery or MTTR”, of course, means the time in which recovery of lost data is possible. RAID systems are “failure tolerant” which means that they can automatically recover their lost data, most of the time. Needing a serious RAID data recovery, therefore, is almost always avoidable because of the very nature of the hardware.

It could also mean that you’re trying to recover files from a damaged RAID. Since the RAID system uses multiple hard disks, you can suffer either partial or whole failure.

You’d think that your database would be safe after you’ve protected it with a RAID backup. But statistics show that of total data loss in any system, approximately 44% comes from hardware failure.

RAID Data Recovery – How Safe is Safe?

How safe is your data using RAID? If your RAID is a combination of several hard disks into one unit, then the simplest answer is your data is only as safe as your weakest disk. This is not to say that you won’t be able to recover your data.

Some RAID’s though are software-hard disk combos. In these hybrids, how safe your data is depends on how you distribute it.

Ask your vendor for a RAID data recovery failure rate. The failure rate of your disk array may be higher or lower than its component hard disks and will hinge on what kind of array you purchase.

RAID Data Recovery – Who Needs It?

RAID is generally found in server computers. The disks that make up the array are usually the same size, although some aren’t.

The rationale behind RAID is the need for bigger data storage. So you’d expect only corporate IT departments or storage intensive firms to use RAID, such as audio and video editing or animation companies.

But two factors are making RAID more popular:
- Many businesses, even small, home-based ones rise and fall on the strength of vital data.
- Technology has driven hard disk prices down, making RAID more widely available so that it’s built into more motherboard chipsets, ergo, into more advance PCs.

RAID Data Recovery – How Much?

If you’re data is crucial to your business it is probably best if you call in professionals to help you when disaster strikes. If you’re thinking of recycling your hard disk and trying to salvage data yourself by running cheap software (around £50 or less), be prepared to lose everything.

There’s one thing you shouldn’t do: Don’t attempt to use software that writes stuff to the damaged hardware. There’s a good chance you can make matters worse by overwriting data that you would have been able to recover otherwise.

Only use data recovery software if you really know what you’re doing. If not, call a pro. But check that you aren’t going to pay for any evaluation charges if all you have is a regular IDE hard disk. Most firms only charge evaluation for complicated RAID’s or network servers.

Here’s what you should expect to pay:

* RAID, SCSI = as much as £15,000 depending on how your storage is configured.