Has it happened to you yet?
Floppy disk with important data went bad?
CD or DVD with your favorite pictures got scratched?
Hard drive crashed without any, warning PC won't boot up?
Unless you have personally experienced the loss of data, whether it is pictures, important documents, spreadsheets, databases, music files, graphics or software, you will never understand why it is so critical to do backups on a regular basis to protect yourself.
Simply put, Backing-up is the activity of copying your files or databases so that they will be saved in the event of an equipment failure or other catastrophe. Backing-up is usually a routine that is part of the daily operation of large businesses using mainframes as well as by the management of smaller business computers. For home personal computer users, backing-up is also necessary but usually neglected.
The retrieval of the files you backed up is referred to as restoring them.
In the field of information technology or data processing, backup refers to the copying of data, so in the event they are needed, these additional copies may be restored after some type of a data loss.
Backups are normally used for two purposes:
1. In the event of some type of disaster, they are used to restore a computer to an operational state following the disaster.
2. In case files have been accidentally deleted or corrupted, you can restore small numbers of files.
What are the types of backups?
1. Full backup
A backup of all (selected) files on the system. This type of backup is essentially a waste of time, for the simple reason that in order to restore files, the operating system must be intact and bootable.
2. Incremental backup
A backup that only contains the files that have changed since the most recent backup (either full or incremental).
The advantage of this is quicker backup times, as only changed files need to be saved.
The disadvantage is longer recovery times, as the latest full backup, and all incremental backups up to the date of the data loss need to be restored in the appropriate order.
3. Differential backup
A cumulative backup of all changes made since the last full backup.
The advantage to this is the quicker recovery time, requiring only a full backup and the latest differential backup to restore the system.
The disadvantage is that for each day elapsed since the last full backup, more data needs to be backed up, especially if a majority of the data has been changed.
No one can ever predict if and when his or her hard drive will crash or when a floppy disk or cd will malfunction. It is no fun when it happens and you find out you has lost data of some type. Determine what you have on your computer that is extremely important to you and set up a plan to back those files up on a regular basis. Very small files can be copied to a floppy disk; large files can be copied to a CD or DVD. Keep a log of what you backup and when, so if you have to recover or restore a file or files, you will be able to easily find what you need.
There numerous software programs available to backup/restore files. Most of them allow you to compress the data that is to be backed and this simply conserves space on the backup medium. For large numbers of files or very large files, this is a good way to go. If you only have a few files and they are small, there is really no reason to compress them. Keep in mind that if you compress the files during backup, you will need the same software to decompress the files if they have to be restored.
Sunday, January 14, 2007
Saturday, January 13, 2007
RAID Data Recovery - How It Works
RAID data recovery is probably one of the most complex processes any data recovery firm can perform. More often than not, the problems are compounded by the actions of the client prior to sending the drives in for recovery. Many users feel that it is important to try and recover the data themselves or repair the array through various system utilities, and this may be fine if the data is not critical. However, it has been our experience that when you have a RAID failure that has resulted in substantial data loss, more often than not, somebody's job is on the line if that data is not recovered. The biggest piece of advise this article can provide in the event of a RAID failure: LEAVE IT ALONE.
IT professionals have a lot of pressure placed on them when a catastrophic system failure occurs. It is their job to make sure that all systems are up and running. Many times, out of panic, troubleshooting processes are initiated in order to correct the problem. Often times these processes only make a bad situation even worse, and in many instances they can render the data unrecoverable. Let's keep in mind what this data can consist of in an average corporate environment. You are probably dealing with information that cost many hundreds of thousands of dollars in labor and resources to create. Much of the data probably can't be duplicated. The intellectual value alone could be in the many millions of dollars. Corporate executives really don't care to hear about how the failure occurred, or what unbelievable string of events led up to the server crashing. They don't care to hear the technical jargon as you try to explain to them what happened, and hope they understand that it wasn't your fault. They only want to know one thing..."why was this data not backed up, and how can we get it back?"
Instead of taking chances on your own, call a data recovery professional. RAID data recovery can be expensive, but in most cases it is much less costly than trying to recreate the data that has been lost. There is a set procedure that most data recovery professionals follow when it comes to performing any recovery work. These procedures are followed and expanded upon when dealing with a RAID recovery. The first step of any RAID recovery is to make sure all of the drives are functional. In order to properly complete the recovery it is essential that all drives are fully functional (this is especially true with a RAID 0). This may involve taking any physically damaged drives into the clean room, in order to make the necessary repairs so that they function normally again. Once that is completed the next step is to make complete, sector-by-sector clones of every drive. This is not "Ghosting", but a very low-level process that allows the recovery technician to work around bad sectors, and have complete control over how the drive functions. During the cloning process, the original source drive that you sent in, is generally put in a "write protect" mode so that no data can be written to the drive. This insures that the original source data is not altered in any way.
Once the cloning process is complete, the original drives you sent in are set off to the side and are no longer touched. The actual recovery process is performed on the cloned copies, so nothing that is done during recovery can make the situation worse. After the drives are cloned, they will be loaded into an emmulator and destriped. Destriping is like taking the scattered pieces of a puzzle and putting them together neatly. Simply stated, destriping is taking the data scattered among the multiple drives that make up array and placing it onto a single destination drive. From there we have a single drive in which we can complete what we would consider to be a "normal" recovery. We can complete this process even at the multi-terrabyte level. If the damage to the stripe is not too severe, in most cases a complete rebuild of the directory structure and all associated data can be completed.
IT professionals have a lot of pressure placed on them when a catastrophic system failure occurs. It is their job to make sure that all systems are up and running. Many times, out of panic, troubleshooting processes are initiated in order to correct the problem. Often times these processes only make a bad situation even worse, and in many instances they can render the data unrecoverable. Let's keep in mind what this data can consist of in an average corporate environment. You are probably dealing with information that cost many hundreds of thousands of dollars in labor and resources to create. Much of the data probably can't be duplicated. The intellectual value alone could be in the many millions of dollars. Corporate executives really don't care to hear about how the failure occurred, or what unbelievable string of events led up to the server crashing. They don't care to hear the technical jargon as you try to explain to them what happened, and hope they understand that it wasn't your fault. They only want to know one thing..."why was this data not backed up, and how can we get it back?"
Instead of taking chances on your own, call a data recovery professional. RAID data recovery can be expensive, but in most cases it is much less costly than trying to recreate the data that has been lost. There is a set procedure that most data recovery professionals follow when it comes to performing any recovery work. These procedures are followed and expanded upon when dealing with a RAID recovery. The first step of any RAID recovery is to make sure all of the drives are functional. In order to properly complete the recovery it is essential that all drives are fully functional (this is especially true with a RAID 0). This may involve taking any physically damaged drives into the clean room, in order to make the necessary repairs so that they function normally again. Once that is completed the next step is to make complete, sector-by-sector clones of every drive. This is not "Ghosting", but a very low-level process that allows the recovery technician to work around bad sectors, and have complete control over how the drive functions. During the cloning process, the original source drive that you sent in, is generally put in a "write protect" mode so that no data can be written to the drive. This insures that the original source data is not altered in any way.
Once the cloning process is complete, the original drives you sent in are set off to the side and are no longer touched. The actual recovery process is performed on the cloned copies, so nothing that is done during recovery can make the situation worse. After the drives are cloned, they will be loaded into an emmulator and destriped. Destriping is like taking the scattered pieces of a puzzle and putting them together neatly. Simply stated, destriping is taking the data scattered among the multiple drives that make up array and placing it onto a single destination drive. From there we have a single drive in which we can complete what we would consider to be a "normal" recovery. We can complete this process even at the multi-terrabyte level. If the damage to the stripe is not too severe, in most cases a complete rebuild of the directory structure and all associated data can be completed.
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