Problems with RAID 5?

Has anyone experienced problems when using RAID 5? My customer keeps getting this error: “There is a corrupted area in the database.” The database is native Navision. Size is 12GB. 5 database parts. Less than 20% used. Hardware configuration: 10 hard drives / mirror + Striped (0+1). Running Windows 2000 server. Best regards, Erik P. Ernst, webmaster

Hi Erik Why use striping when using native DBMS? RAID 0+1 is ideal for the data part ocf the database when running SQL, but when Your’e using native DBMS You should use mirroring only, so that Your HW displays separate physical drives to the OS. In that way You get one commit cache for each drive/database part. With Your current configuration You only have one commit cache. //Lars

Thank you for your advise. But should the fact that the customer is using 0+1 could effect the problem described? And what about virus? Is any virus know to be able to cause such problems? Best regards, Erik P. Ernst, webmaster

Do You have any write cache’s enabled? Even in the HDD’s You can find a write cahce, and I can just imagine the trouble for the DBMS if You have a a striped set of disks with write cache on each disk. Nevertheless I recommend You to switch over to RAID1. It’s certainly safer and I’m quite convinced that You’ll get better performance that way. //Lars

Another performance isue is the combination of “Stripe-Set size” and “Read-Ahead cache”. Navision/Attain write 8 kb blocks randomly, so if your “Stipe-Set size” is eg. 32 kb, then the RAID-controler reads 32 kb each time Navision neads 8 kb.