Cache Write Pending

[Lai Nee Shyang_1]

Hi there.

Need someone to enlighten me on this storage paramaeter. On my storage system I observe a constant 10% cache write pending, but occasionally it spikes to abt 20%. Some question puzzling me :
1. What is write pending? Is it data from Host waiting to be written to the storage cache or data on storage cache waiting to be written onto disks?
2. What is controlling the amt of cache for write pending ? If the storage cache allocated for write pending is limited to 10%, does it equates to IO from hosts have to wait if the 10% is full ?
3. Is there any technical documents giving more details on this topic (no brochure pls).

Thanks.. Appreciate if anyone can help.

LAI