Question about fix hold time: buffer insertion

For the tool update but the process not, I met the fix hold problem.

I am using the encounter 6.2 to process the 3al 0.6um design.

During the hold fix phase, the tool insert too much buffers(for example 10k numbers)!

Such case I did not meet when I use se5.3 tool. I often insert less than 100buffers at most in the past!

For the  library is too old, information such as footprint can not privided by it.

So I think maybe this problem is partly aroused for this reason. For example, the tool did not get exclusive delay buffers to  insert, and just insert buffers according to the logic equivalent generated footprint. So some driving buffers are inserted for delay purpose, then many many buffers are inserted! This just what I think, maybe not true. But I am not familiar with frontend, and the communicate with front end designer is not that smoothly. So I did not get answers from front end designers.

I have found two cells to be used as delay buffers(only this two cells).

but I do not know which command should be used to achieve this.

for every time, the tool also insert other logic equivalent cell(with strong drive ability) to fix hold!

I want to try to just use two cells to be used to fix hold violations. I try to revise lib to add footprint to achieve this, but get many errors!