[pve-devel] new cache benchmark results

[Alexandre DERUMIER]

>>Another problem with cache=none is that it does not work with 4K sector drives. 
>>
>>User reported problems with 4K iscsi and 4K local disks. 
>>
Yes, I remember the post in the forum. It doesn't work with cache=none or cache=writeback

>>Any idea how to solve that? 
This is strange, because it seem to be fixed a long time ago(I have seen some redhat bugzilla from 2011 about it)
But I don't have hardware to test it :(


I'll look in my archives tomorrow ;)


----- Mail original ----- 

De: "Dietmar Maurer" <dietmar at proxmox.com> 
À: "Alexandre DERUMIER" <aderumier at odiso.com>, pve-devel at pve.proxmox.com 
Envoyé: Jeudi 8 Novembre 2012 17:50:58 
Objet: RE: [pve-devel] new cache benchmark results 

> 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...) 

Another problem with cache=none is that it does not work with 4K sector drives. 

User reported problems with 4K iscsi and 4K local disks. 

Any idea how to solve that?