Re: Database and RAID

Syed wrote: > > This is what i always wanted to know as well. At the moment we also need > to decide either to use Database mirroring option or RAID system. I was > told by the hardware engineer that using RAID system is much safer since > failure other than the database will be taken care. I was also told that > any problem in the database will prompt for the RAID system to switch to > the mirrored harddisk, i am not sure to what extend this is done. I was > asking if the space allocated for Online system is full, or any chunk is > down can the RAID system take care, he was unable to assure, but said > that there must be a way to take care those problem. We decided to go > for RAID system, only after the system alive which i expect to be > somewhere in August i will be able to know the performace. I would also > much appreciate any input on this matter. See my response from yesterday. What RAID level? From your discussion I assume RAID 1 (mirroring). This is fine. For performance, Informix benchmarked its own mirror -vs- OS and Firmware/hardware mirroring systems several years ago under 5.0x. They found firmware mirroring to be fastest by a safe margin and OS level mirror and Informix mirror to be equivalent with OS mirror the slight favorite. Informix mirror is by far the easiest to maintain though. Also 7.2x+ knows about the Informix mirror and can take advantage of it to improve performance so the results under 7.2x+ may be better than under 5.0x were. Art S. Kagel