Hi… I am still a little confused about support of Raid-5, and Multiprocessor servers… Most apps I have worked with are oblivious to these enhancements do I, or don’t I… and why… Thanks in advance for any help on this… gary…
Hi. You’ll get much better performance on RADID1 than RAID5 because Navision’s DBMS have one commit cache for each physical disk. Since RAID5 is treated as one physical disk by Navision, You’ll only get one commit cache on a system running RAID5. You’ll gain write performance in a linear relation to the number of physical disks You put in on You system up till eight disks. Onother reason why RAID5 is slower is the overhead in handling the parity information. Conclusion: Do not run Financials on RAID5. Then the processors. Navisions DBMS do not Use much of Your CPU. If You watch the performance monitor You’ll se that the CPU doesn’t have much to do. Even when in those cases where You have a hig CPU load You won’t gain much performance in adding a CPU.
This is not entirely true. If you run Navision with the SQL 7.0 Server Option, then Navision (and Microsoft) actually recommends that the database is placed on RAID5 and the logfiles on RAID1. /Lars
CPU Usage with the native Navision database depends on the amount of cache you allocate (and whether you are brave enough to use the commit cache.) The more cache, the more that the CPU speed matters. Back in the olden days when RAM was so expensive, this was not as significant as today. Now you really can put 512MB or more of RAM on a system at a reasonable price and get benefit from the faster CPU speeds. Jim Hollcraft aka Skater drilldot.com Unauthorized Navision News
Different levels of RAID optimize different factors: speed, reliability, time to recover from a failure. The recommendation to use RAID5 for the database and RAID1 for the transaction file is a balance of these factors. This article give a good overview of RAID: http://www.sunworld.com/swol-09-1995/swol-09-raid5.html Does embedded HTML work here… RAID: What does it mean to me? Jim Hollcraft aka Skater drilldot.com Unauthorized Navision News