Keep Detailed Change Logs
A very good way to protect yourself in this area is to keep both an operating system change log and a database change log. Make a big to-do out of this. Use a real paper notebook, too, not just a file on the computer. All of these computer files could disappear as a result of a crash. Religiously enter database and operating system changes in the log. You'll be surprised at how much tweaking and tuning you do "on the fly." If you have to rebuild the system, these logs will be invaluable.
On the subject of logs, occasionally clean out the online.log for your database. Don't just let it build forever. When you clean it out, save the parts you clean out so that you can refer to them later if necessary.
Buy Quality Hard Drives
Buy the best drives you can afford. When comparing drives for your system, look at the specifications; all other things being equal, buy the drive with the longest MTBF rating.
Balancing Performance and Drive Size
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Using one large drive rather than more smaller drives does not necessarily mean you'll get the best performance out of your system. Read on...
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Purchase bigger drives. If you find a 2GB drive and a 20GB drive with an equal MTBF rating, buy the 20GB drive rather than ten 2GB drives. With equal MTBF ratings, the odds of failure will be less for one large drive than for ten smaller drives.
In case you're overly concerned about performance, read my thoughts about that issue.
Improve Your Disk Layout
When you add chunks to your dbspaces, vary the size of the chunks by a few bytes for each chunk. Rather than creating three 2GB chunks, for instance, create one that is 2.00GB, one that is 1.99GB, and one that is 1.98GB. This is much more important if you are not using raw devices for your chunks. If you ever have to recover the data, the name of the space or chunk may be lost, but if you have slightly different-sized chunks and you have a copy of the directory holding them, you will be able to differentiate among them by their size as well as by their name.
This is most important in Informix on Windows NT. If you are using operating system files and your system crashes, Windows may attempt to recover the crashed files itself. It will rename those files to something like FILE1, FILE2, etc. If they are all the same size, you won't be able to tell which is which.
