i am thinking using raid 0 (2x80gb ide drive, or 2x36 gb scsi drive), rather conventional raid 1, for my colocated server.
Raid 0 is very risky, but with the benefits of speed and cheap, as compared with Raid 1. Most people use raid 1, do not use raid 0. And also do offsite back up.
I intent to rely on my home computer to do daily backup only.
I think offsite backup has advantage and disadvantage vs. Raid 1. But in the end, the advantage is over disadvantage, if my file/websites is not so critical.
advantage of offsite backup: very safe, can against corrupted data, easy to use, easy to set up. can against many other disasters that Raid 1 can not (fire, etc. )
the only major advantage of Raid 1 compare to offsite backup is, you May recover and be back online several hours earlier as compare to offsite backup, when there is a hard disk failure. But hard disk failure is very rare.
Backups maintain history so you can roll back versions of files. RAID simply provides drive integrity.
If you delete a file, RAID isn't going to get it back for you. If you overwrite a file, RAID isn't going to get it back for you. If the file is corrupted by software, RAID isn't going to help you.
The only time RAID helps is if a drive fails (or with striping, makes I/O faster). It saves you the time and hassle of restoring from a backup if a hard drive fails. With a good hot swap system, you can just yank the drive and plug in a new one without missing a beat.
My preference is RAID 5. Go look up "raid definitions" at Google and you'll see why.
Don't do RAID 0. For hosting, that would be disasterous. RAID 0 is used for things like digital video recording and other mass disk I/O intensive operations. Hosting isn't that way.
With RAID 0, you have to replace the hard drive and restore from a backup just like a single conventional hard drive failure. Your OS will be corrupted, your data will be partial (at best), and you probably won't be able to boot if you have a failed hard drive with RAID 0.
Use Raid5 with backup. Striping (raid 0) may speed you up a bit but doubles your chance's of failure. Raid is only good in case of hard drive failure which is the biggest reason for data loss nowadays but it is not a backup its a fail safe. For backup you realy don't use raid 1 you just do backup to another harddrive. You can do it on site or off site on site will be cheaper but if you have the money off site works.
Raid 0 means if you have 2 hd's 80 gig's each you can have 160 gigs storage but if one hard drive fails you lose ALL every bit of data.