[pve-devel] new cache benchmark results

[Alexandre DERUMIER]

netapp nfs: raw file 
--------------- 

default(no drive cache option) : 8000 
none: 13000 
writeback = 8000 



netapp nfs: qcow2 file 
--------------- 

default(no drive cache option) : 5000 
none: 12000 
writeback = 5000 


local raid controller (512MB CACHE with battery): raw file 
------------------------------------------------- 
default(no drive cache option): 10000 
cache=none : 4000 
cache=writeback : 10000 


local raid controller (512MB CACHE with battery): qcow2 file 
------------------------------------------------- 
default(no drive cache option): 9000 
cache=none : 6000 
cache=writeback : 9000 




So writeback seem to be faster on local storage, but slower on network storage.

Note : with shared storage, with writeback, I generally see big spike (faster than cache=none), but after big slowdown (near zero) during 5-10s.
       So I think this is when the host need to flush the datas, it add more overhead. (maybe network latency have an impact...)