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The spring season is in bloom. For most, it represents a time of warmer temperatures and relaxation. But unfortunately, it can also mean strong storms including lightning strikes. As these storms are now appearing on a more frequent basis, is your computer system protected? A power surge can cause a computer system to crash and can also cause data loss by causing the read/write heads to malfunction. It can occur as one large surge or multiple spikes over a period of time. The following tips provide information on how you can ensure your system does not fall victim to a power surge.

Power Down and Unplug The System During Bad Weather

This is a tip that most users disregard, but powering down and unplugging the computer system during bad weather is the best way to safeguard against a power surge. For those operating servers, this may not be an option. For those who fall into this category, continue reading below. But for most home users, powering down and unplugging is certainly an option that can be followed.

Use a High Quality Surge Protector

During a power surge or spike, there is excess voltage in the electrical lines above that which is normal. A high quality surge protector can absorb the excess voltage preventing it from damaging your system. It is important to do your homework before you purchase a surge protector. You should compare the ratings and ensure you are getting a good quality surge protector. It is also important to remember that while a surge protector helps, it is not a guarantee against a direct lightning strike. Powering down and unplugging the system is the sure way to protect against lightning strikes.

Consider Using a UPS (Uninterruptible Power Supply)

A UPS can protect your system from damaging power surges by allowing your system to remain running after a power outage. A built-in battery inside the UPS unit allows it to accomplish this. This enables users to save their files and shutdown the software properly. Many high quality UPS units have the capacity to automatically power down the computer system and save any data that was work in progress.

Contact a Hard Drive Recovery Company If Your System Has Suffered a Power Surge

If the data on the hard drive is worth preserving, you can contact a hard drive recovery company to recover the data. A power surge can cause the read/write heads to malfunction or cause a head crash. Continuing to operate the drive can cause damage to the platters- which can in turn cause permanent data loss. A data recovery lab can replace the internal parts of the hard disk and retrieve the existing data.

As the winds blow and the lightning strikes, it is important to know if your system is protected. A power surge can be devastating to your computer system and hard drive. By following the tips above, you can ensure that your computer system and data remain safe.

This article can be freely published on a website however it must not be modified in any way including the author bylines, and the hyperlink must be made active as shown below.

Andrea Stone is employed with ReWave Hard Drive Recovery, a worldwide data recovery company. Visit the company’s Hard Drive Recovery website for more information.

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Now a days managing files and folders on PCs seems to be a critical task for network administrators and data storage managers due to huge capacity hard disks and millions of files and folders.

This article will help you in two ways

1. Understand the disk space allocation and wastage.

2. Understand how to manage your disk space.

Topics covered

• 1. What is File Allocation Table (FAT) ?
• 2. Disk Efficiency and FAT.
• 3. What is Wasted Space. ?
• 4. Solution.

What is File Allocation Table

The FAT is a roadmap, or index, that points to the location where all the information in files is stored on a floppy disk or hard drive. The FAT is extremely important because the system uses it to store and retrieve files containing information.

When you save a file in Windows, it is stored in multiple pieces (in clusters made up of multiple sectors) on the disk. Windows also saves the roadmap, or index, that points to these clusters in two copies of the FAT (File Allocation Table). The FAT contains the directions to all the pieces of your files, so that applications can find them again later

Disk Efficiency and FAT.

Every file on your system is stored in clusters in your hard drive, the maximum of one file can be stored in a particular cluster, so this results in wastage if the file is under the cluster size. The current FAT version (FAT16) organises files in 32K clusters in drives over 1.2gig, while FAT32 will use a minimum cluster size of 4K. This means that a 3K file wastes only 1K of disk space on FAT32, while it wastes 29K of space on a standard FAT system. This wastage can result in over 50% of a 2gig drive being wasted. See the table below.

What’s a cluster and why does cluster size matter?

The whole problem of wasted space arises from the fact that DOS allocates file space in “clusters”. Clusters are sequentially numbered on the disk, starting at 0, and cluster numbers are used both in the FAT (file allocation table) and in the individual directory entry for each file.

Allocation by clusters means some space on the disk will be wasted. Regardless of the actual length of a file as reported by the DIR command, the file will actually occupy a whole number of clusters on the disk. So a 1-byte file will actually use a whole cluster, a file that’s 1 cluster plus 1 byte long will use 2 clusters, and so on.

Is this serious? It can be, depending on the pattern of file sizes on your disk. For instance, if you have an 2GB disk with 5,000 files on it, about 100 MB of your disk is being wasted. And the figures can be much worse, depending on the pattern of your usage. One user reported copying 450 MB of files to a 1.6 GB disk and having them take up 600 MB! As your disk approaches being full, you may wish you could squeeze some extra space out of it instead of buying a new disk.

How does cluster size depends on hard-disk size?

As mentioned above in the table the cluster size for various partition sizes so that you can make intelligent choices about how to partition your hard disk.

From the above table we see that even 2.1 GB drive is over the 1023 kilo-byte limit for 16 KB clusters and therefore its cluster size (unpartitioned) is 32 KB. With a 32 KB cluster, even a 1-byte file will use 32 KB of disk space. A file whose length is 32,769 to 65,536 bytes will likewise use two clusters (64 KB), and so on for higher file sizes.

Even so, you may be inclined to think this is no big deal. But think about it: if you have a 2.1 GB drive with 5,000 files, you’re probably wasting about 160 MB.

How are cluster sizes determined?

Clusters are always some power of 2 times 512 bytes, but just which power of 2 depends on the disk size. Why should this be so? I mentioned above that clusters are numbered sequentially. The problem is that the directory structure and the FAT have room for only 16 bits for a cluster number. Since the largest unsigned number that will fit into a 16-bit field is 2^16-1 = 65535, the disk can hold at most 2^16 = 65536 clusters. This gives the formula

disk size

cluster size = ———, rounded up to a power of 2

65536

In general the wasted space per file will be half a cluster.

—–

What is Wasted Space?

Whenever a file is created, space will be allocated to the file in the form of clusters. A cluster can be of 8 KB , 16 KB or 32 KB depending upon your hard disk partition size. Following is the chart for cluster size.

FAT FAT32

Partition Size Cluster Size Partition Size Cluster Size

128 - 256 MB

4 KB

1 - 8 GB

4 KB

257 - 512 MB

8 KB

8 - 16 GB

8 KB

513 - 1024 MB

16 KB

16 - 32 GB

16 KB

1025 - 2048 MB

32 KB

>32 GB

32 KB

So the formula for wasted space is Wasted Space = Allocated Space - Actual File Size.

We will take an example of file which is of 900 bytes in size and your partition type is - FAT and its size is 1024 MB. So the allocated space for your file will be 16384 bytes or 16 KB whether you store 900 bytes or 1 byte in the file. So the wasted space in this case will be

Wasted Space = 16384 - 900 = 15484 bytes.

So the conclusion is : Lesser the file size, more the wasted space.

Solution

So to analyze how our disk space is being wasted we need a smart program which will show us the space hogging files and their locations.

We are working with File system softwares since last 2 years. We have developed a powerful disk space analysis and cleaning software - DiskAnalyzer Professional 1.5 which allows you to take control of your disk space and reclaim gigabytes of lost disk space.

You can visit our website to get more information about the software http://www.craveworldwide.com

Manoj Shinde

Crave Worldwide, India.

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If I asked you the question: which part of your computer is the most fragile, what would you say? What if I asked: which part is most important to you?

Often, the answer to both of these questions is your Hard Drive.

Your hard drive is likely one the most important things you own. It contains work data, school data, emails, photos, music, movies, tax information, etc Incidentally, the hard drive is also one of only two moving components in your computer (the other being your optical drive). The following is a list of important maintenance and monitoring techniques you can use to maximize the life of your hard drive and prevent data loss.

Hard drives are physically fragile - handle with care
Statistics show that 25% of lost data is due to a failure of a portable drive. (Source: 2001 Cost of Downtime Survey Results)
Contrary to its seemingly rugged appearance, your hard disk is a very delicate device that writes and reads data using microscopic magnetic particles. Any vibration, shock, and other careless operation may damage your drive and cause or contribute to the possibility of a failure. This is especially relevant for notebook users, as they are most at risk of drive failure due to physical damage, theft, and other causes beyond their control. That’s why we recommend regular backup of notebook hard drives, as often as possible.
Possible solutions include external USB or Firewire drives (although these are prone to the same risks), desktop synchronization, or backup at a data center through the web.

Hard drives write data in a non-linear way forcing it to become fragmented.

When files accumulate on your hard drive, they do not just get written in a linear fashion. A hard drive writes files in small pieces and scatters them over the surface. The fuller your hard drive becomes and the more files you save and delete the worse file fragmentation can be. Hard drive access times increase with fragmentation since your drive must work harder to find all the pieces of the files. The more fragmented your data is, the harder the actuator arm has to work to find each piece of a file.

A case in point:
Disk fragmentation is a common problem for users of Outlook Express and database software. Each time outlook saves new mail, it does so in a different physical location from the previous time. This results in extreme fragmentation, causing longer hard drive access times and forcing more strain on the heads. This strain can eventually lead to a head crash, and often that means a virtually unrecoverable drive.Finally, in the event of a total crash, a fragmented drive is much more difficult to recover then a healthy defragged drive.

Luckily, Windows makes it remarkably easy to defrag your hard drive, simply launch the Disk Defragmenter utility (Start > Programs > Accessories > System Tools), choose which disk or partition you’d like to defragment and set it to work overnight or while you are not actively using your computer. Defragmentation will speed up your computer and ensure a longer life for your hard drive.

A very small power surge can fry a hard drive - use a UPS and turn off your computer when you can

Another little-known fact about the fragility of your hard drive is its susceptibility to electrical failure. An electrical failure can be caused by a power surge, lightening strikes, power brown-outs, incorrect wiring, a faulty or old power supply, and many other factors. If a power surge enters your computer, it may do an unpredictable amount of damage, including destroying your hard drive’s electronics or crashing the heads and possibly resulting in total data loss.

The best way to protect your computer from such dangers is to use a highly rated protected power bar or an Uninterruptible Power Supply (UPS). Although these devices won’t eliminate the chances of a crash, they will serve as effective protection in most cases. Also, you can minimize the danger of an electrical problem and reduce wear of your hard drive by turning off your computer or using power-save modes whenever possible. It’s a known fact that 100% of drives fail, the question is when will it happen and will you be prepared? Make sure to check out the knowledgebase section of our website for more detailed information on how electrical power affects your computer.

Be SMART, monitor the health of your drive to prevent unexpected crashes

All modern hard drives have a self-monitoring technology called SMART (Self Monitoring Analysis & Reporting Technology). What most people don’t realize is that the majority of hard drive failures do not have to be unexpected. Most failures occur as a result of long-term problems which can be predicted. By regularly monitoring disk health and performance, you can know about potential hard drive problems before you lose any of your data.

Several excellent utilities are available, including DiskView and Stellar SMART for standard IDE and SATA desktop drives. Also available are tools that monitor the health of SCSI drives and full RAID Array systems. Ariolic Software offers a great utility called ActiveSMART.

The only fool-proof way to prevent data loss is… Backup!
If you only take one of the suggestions here to heart, let it be this one: always back up your important data. After all the monitoring and all the prevention measures are in place, one fact still remains: all hard drives fail. Backing up regularly will ensure that you’re never caught without your critical data. For individuals, the simplest solutions include external portable hard drives, dvd’s, and online storage. For businesses, we recommend renting space at a secure data centre and implementing a disaster recovery plan, regardless of the size of your business.
I hope that the above techniques give you some idea of the importance of hard drive maintenance and provide some insights in how you can protect yourself from data loss.

Alex Bezborodov is the technical writer for Accurate Data Recovery, specializing in data recovery for end users, academia and small businesses. Check out the ADR Resource Center for more useful information.
Let ADR bring your data back to life!

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