checkpoint spikes

Now that long checkpoints topic is in discussion I would like to get some help too. We are also getting into a similar problem with long checkpoints (over 13 secs sometimes). Long checkpoints in our case only happen once in a while. Our LRU_MAX and LRU_MIN are at 2 and 1. Our checkpoints mostly complete in 0 sec as LRU writes are continously cleaning out the buffers. Other parameters are: LRUS 28, Cleaners 28, NUMAIOVPS 24, BUFFERS 100000, CKPTINTVL 180 We are running IDS 7.30.FC7 on HP-UX 11 with 6 cpus given to this instance having 150 max concurrent users. There are 76 chunks residing on 29 disks. We do know that the system is a lot busier (more updates/inserts/deletes) when we see a long checkpoint. Would like to know what measures can be taken to eliminate the checkpoint duration spikes. Would addition of more LRUS and cleaners solve this problem (over 3500 buffers/LRU). How can I find out if the bottleneck is a disk? Also, if more AIOVPs are needed? Thanks Shehla

When onstat -g ioq shows a backlog for aio, try incrementing NUMAIOVPS. A a rule of thumb, two aio VPs per frequently accessed disk. Nona