Saturday, March 05, 2005
Backing up data:
· What types of back up are there?
1. Image Back up – The entire drive is copied as an image to a CD and Ghosted back onto a drive after a catastrophic event – restores all software back to a certain point and main user data – also used when rolling out machines of common hardware and software – eg in business where all the machines are leased from say IBM they need to get them up and running fast rather than sit there load all the programs and then copy the common user data across.
2. Archival Backup - A type of backup in which all files on a drive or directory are copied to a backup storage device. Archival backups are also called full backup. Your back up software will do one of these the first time you do a back up.
3. Incremental Back up - Any backup in which only the data objects that have been modified since the time of some previous backup are copied. This means your back up software compares the drive library it has stored and notes changes and brings across into the image files of which have been modified since the last backup. This saves the amount of time it takes to do a back up.
· What media do I use to back up my data?
1. It truly depends on the amount of data you need to back up, eg. How big the hard drive is? How much time you could afford to be “down” restoring your computer system after a crash? How much money you want to spend on hardware and media? As well as how long you need to store the items for? NO one really understands how important back up is until they have lost everything.
2. DVD & CD ROM – most common used these days as DVD can store anywhere between 4.8gb to 10gb depending on compression and media format used. They do however, require special treatment for storage. In contrast CD can only store images 640mb which often hold 1gb of compressed data.
3. TAPE cartridges – Slower than DVD but can store vast amounts of data. However these days the tape cartridges the cost levels are much more expensive than other types of back up but still the most reliable.
4. Memory Sticks – can store upwards of 32mb to 1gb of data. They are perfect for transporting whole directories and doing short term back ups –eg during a computer change over at work where a new image and hardware is being rolled out. However, they have the abilities to be lost easily, stolen or wiped by Radio Frequency fields. They also have the been used in data theft from companies during the development of products so a lot of companies have band these devices as they can be included in things like Watches, Swiss Army Knives and the humble parker pen.
5. Floppy Disc’s – these are completely unreliable and only store small amounts of data but would be ok for a 24 hour back up of files.
Where do you store your back up data?
On site – Storing your data on site means it needs to be kept secure. A fire proof safe should be utilized. Remember this data is your lively hood so it should be treated like money.
Off site backup – if the place burns to the ground your data may have been destroyed or been cooked possibly in the safe by the extreme temperatures. You need to store at least two backs ups a business week off site. Depending on the type of data you should provide the appropriate security.
Conditions – all media should be kept in a cool, moisture free, away from excess light and kept clear of magnetic or electro magnetic and radio frequency fields
Restoration –
When a catastrophic event occurs. You need to locate the latest back up immediately. Restore the computer to the point where the updating system can be done from the back up and restore software.
Often businesses will have a Image back up they restore from they will ghost the machine’s main operating system and programs across back into operation and then restore the data directories.
· What types of back up are there?
1. Image Back up – The entire drive is copied as an image to a CD and Ghosted back onto a drive after a catastrophic event – restores all software back to a certain point and main user data – also used when rolling out machines of common hardware and software – eg in business where all the machines are leased from say IBM they need to get them up and running fast rather than sit there load all the programs and then copy the common user data across.
2. Archival Backup - A type of backup in which all files on a drive or directory are copied to a backup storage device. Archival backups are also called full backup. Your back up software will do one of these the first time you do a back up.
3. Incremental Back up - Any backup in which only the data objects that have been modified since the time of some previous backup are copied. This means your back up software compares the drive library it has stored and notes changes and brings across into the image files of which have been modified since the last backup. This saves the amount of time it takes to do a back up.
· What media do I use to back up my data?
1. It truly depends on the amount of data you need to back up, eg. How big the hard drive is? How much time you could afford to be “down” restoring your computer system after a crash? How much money you want to spend on hardware and media? As well as how long you need to store the items for? NO one really understands how important back up is until they have lost everything.
2. DVD & CD ROM – most common used these days as DVD can store anywhere between 4.8gb to 10gb depending on compression and media format used. They do however, require special treatment for storage. In contrast CD can only store images 640mb which often hold 1gb of compressed data.
3. TAPE cartridges – Slower than DVD but can store vast amounts of data. However these days the tape cartridges the cost levels are much more expensive than other types of back up but still the most reliable.
4. Memory Sticks – can store upwards of 32mb to 1gb of data. They are perfect for transporting whole directories and doing short term back ups –eg during a computer change over at work where a new image and hardware is being rolled out. However, they have the abilities to be lost easily, stolen or wiped by Radio Frequency fields. They also have the been used in data theft from companies during the development of products so a lot of companies have band these devices as they can be included in things like Watches, Swiss Army Knives and the humble parker pen.
5. Floppy Disc’s – these are completely unreliable and only store small amounts of data but would be ok for a 24 hour back up of files.
Where do you store your back up data?
On site – Storing your data on site means it needs to be kept secure. A fire proof safe should be utilized. Remember this data is your lively hood so it should be treated like money.
Off site backup – if the place burns to the ground your data may have been destroyed or been cooked possibly in the safe by the extreme temperatures. You need to store at least two backs ups a business week off site. Depending on the type of data you should provide the appropriate security.
Conditions – all media should be kept in a cool, moisture free, away from excess light and kept clear of magnetic or electro magnetic and radio frequency fields
Restoration –
When a catastrophic event occurs. You need to locate the latest back up immediately. Restore the computer to the point where the updating system can be done from the back up and restore software.
Often businesses will have a Image back up they restore from they will ghost the machine’s main operating system and programs across back into operation and then restore the data directories.
# posted by Peter Saville - IT Consultant @ 2:02 AM 
