Data backup methods questions
Started by
aaaa44
, May 22 2009 02:55 PM
#1
Posted 22 May 2009 - 02:55 PM
#2
Posted 22 May 2009 - 03:14 PM
1) Yes, any file is vunerable.
2) Possibly, yes. A lot of virii can attach to external devices which is how they spread.
3) If the PC was to be stolen, no it isn't any better. A backup solution is only as good as the weakest link. RAID 1 will not help if the PC ends up in the back of a burglar's van.
4) Thumbsticks/Flash drives do have a limited lifespan as you can only write a few thousand times to them. No storage media has an infinite life - NOTHING lasts forever. Flash media wears out. Hard drives mechanically die. CDs and DVDs can die a death relatively easily and often by accident. Moral of the story: If there's something you really cannot afford to lose (such as for example archive video footage of now dead relatives), make multiple copies. You don't have to guard them with your life, just ensure you're not down to only one copy.
2) Possibly, yes. A lot of virii can attach to external devices which is how they spread.
3) If the PC was to be stolen, no it isn't any better. A backup solution is only as good as the weakest link. RAID 1 will not help if the PC ends up in the back of a burglar's van.
4) Thumbsticks/Flash drives do have a limited lifespan as you can only write a few thousand times to them. No storage media has an infinite life - NOTHING lasts forever. Flash media wears out. Hard drives mechanically die. CDs and DVDs can die a death relatively easily and often by accident. Moral of the story: If there's something you really cannot afford to lose (such as for example archive video footage of now dead relatives), make multiple copies. You don't have to guard them with your life, just ensure you're not down to only one copy.
#3
Posted 22 May 2009 - 03:20 PM
Externals are vulnerable to viruses when they are attached and powered up to the computer, as is any disk in the system. It depends on what the virus does and what it looks for.
If you setup RAID1 on your computer, then you should not lose any data. regular backups are also needed, but you can lose data between backups.
Everything has a limited life. I have also had a SD memory card fail on me. I have heard that there is a limited number of writes, but it is a large number typically.
The reason to backup on DVD and/or CD is then you have a running history of the data, not just the last copy. For example, if you backup all your data and a file got corrupted sometime in the past, you will just have the same corrupted data on your most recent backup. If you backup to DVD/CD, then you can keep going back in time until you find a good copy. If you backup to a memory device, you should have three copies. If something goes wrong, you don't want to wipe out the most recent copy of the data.
There are two issues in which backups are used: complete disk failure and individual file recovery.
One example of issues with backups is a machine which was running for a long time. Backups were done each night and full backups each month or week (I forget which), but the OS got corrupted and the full backups were only retained for a year. The machine had been up for more than a year (server). That meant that there were no good backups which could be used to restore the computer to a bootable condition. There was an alternate boot disk, but others decided to copy the data each week, rather than 24 hours after it booted. That also meant that the alternate boot disk also had the same corrupted files.
This means that it would be a good idea to backup your system after you get it to a known good state. Make a DVD/CD and retain it. Then do daily, weekly or monthly backups to a cheap & easy media, based on how much data you are willing to lose. Create new DVD/CD backups every so often, again based on what you are willing to lose.
If you setup RAID1 on your computer, then you should not lose any data. regular backups are also needed, but you can lose data between backups.
Everything has a limited life. I have also had a SD memory card fail on me. I have heard that there is a limited number of writes, but it is a large number typically.
The reason to backup on DVD and/or CD is then you have a running history of the data, not just the last copy. For example, if you backup all your data and a file got corrupted sometime in the past, you will just have the same corrupted data on your most recent backup. If you backup to DVD/CD, then you can keep going back in time until you find a good copy. If you backup to a memory device, you should have three copies. If something goes wrong, you don't want to wipe out the most recent copy of the data.
There are two issues in which backups are used: complete disk failure and individual file recovery.
One example of issues with backups is a machine which was running for a long time. Backups were done each night and full backups each month or week (I forget which), but the OS got corrupted and the full backups were only retained for a year. The machine had been up for more than a year (server). That meant that there were no good backups which could be used to restore the computer to a bootable condition. There was an alternate boot disk, but others decided to copy the data each week, rather than 24 hours after it booted. That also meant that the alternate boot disk also had the same corrupted files.
This means that it would be a good idea to backup your system after you get it to a known good state. Make a DVD/CD and retain it. Then do daily, weekly or monthly backups to a cheap & easy media, based on how much data you are willing to lose. Create new DVD/CD backups every so often, again based on what you are willing to lose.
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