As I visit both newer and older clients alike, I often find that backup strategies have fallen into limbo over the years. This is usually caused by one of the following:
1) The backup tape drive or device that the company was using has broken down and no one noticed or made a decision to have it repaired or replaced.
2) The person who looked after the backups left the company and their replacement was not informed as to how system backups were performed and validated.
3)† Backups and backup validation seems monotonous and people just consciously or subconsciously choose not to do them or just forget about them.
Over the years I have seen several companies lose their complete accounting system when their computer or server crashed and it turned out that their backups were defective or just not being done with any regularity.
Similarly, individuals seldom backup personal files and e-mail on their local computer which can be lost in the case of theft or hardware failures. Occasionally, a computer will crash and we can still retrieve files from the hard drive but often these files are gone for good.
With the advent of larger individual hard drives, portable hard drives and USB Flash drives, which are all fairly inexpensive, some simple secondary backup strategy can go a long way to make sure you donít suffer a major data loss. A high percentage of companies that suffer a complete data loss fail within a year of the event so I canít stress the importance of these procedures enough. Even the loss of a single complex spreadsheet can result in days of work reconstructing the lost file and the data it contains.
The best form of backup for a File Server is one that utilizes a series of rotating tapes or other media. A simple rotation would be to have 5 tapes or disks labelled Monday, Tuesday, Wednesday, Thursday & Friday. Switching the media each day ensures that you have at least 5 backups that you can use if you need to.
Since most tape drives typically erase each tape before backing up, this strategy would not allow you to recover a file deleted several weeks ago but not missed until today. More complex rotations alternate Week 1,2,3 and Month 1,2,3 etc. backup media alternating these tapes on Fridays while still using Monday thru Thursday media during the week. This would typically allow access to files deleted at any time within the last three months providing an extended period of protection.
ALTERNATIVE BACKUP MEDIA
Interchangeable disk cartridges and rewriteable CDís and DVDís are advantageous in that they can capture files and data without erasing what was backed up the previous time the media was used. This provides better protection in simple rotations providing the media has sufficient space to contain both current and older files.
Occasionally users delete files deliberately and it must be noted that these files will still remain on the previous backup media unless the media is deliberately erased before the next backup. This is not usually a problem unless the files are of a confidential or personal nature.
Interchangeable disk cartridges are probably more reliable than CDís or DVDís but the latter are far less expensive and could even allow you to keep separate daily backups for an entire year at 25-50 cents per disk.
As I have noted in previous articles, maintaining at least two different types of backup media helps make sure that data recovery will be possible when and if the need arises. This may entail rotating tape or disk backups combined with a nightly backup to a large user hard drive, portable hard drive or even a high capacity USB drive. The more physical places your data resides, the more likely you will be able to easily recover it.
This leads logically into off-site backups. Backups are of little use if they are destroyed along with your server. Similarly I have had clients lose both their computers and backup media to theft when both were left out on the desk next to each other. A fire proof vault may be safe against theft, but many such safes still get hot enough to melt CDís and other plastic media. They are often only fire proof rated for paper and little else.
In most of my server based networks I usually setup user folders on the file server to store Word and Excel files and such. Then if you have a good server backup scheme these files will be protected. Many individuals still store many files on their local hard drives however. If you use Outlook or Outlook Express for e-mail, your e-mail files are likewise stored on your local hard drive.
The simplest form of backup in the case of individual
computers is to use a