[pve-devel] firsts cache benchs results

[Alexandre DERUMIER]

>>I do not really understand that. 
>>
>>The qemu iscsi.c driver ignore the BDRV_O_NOCACHE flag, so how can this result in any difference?! 
>>
><see qemu-kvm/block/iscsi.c 

I'll redo tests to day.


for sheepdog, libiscsi, maybe BDRV_O_NOCACHE make sense, as host don't see the devices, so host can't cache.
librbd use his own cache implementation on host.( qemu writeback option, activate librbd cache = true)

I think that sheepdog have a writeback cache mecanism, but I need to read the doc.


I'll keep you in touch today with nfs results.

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

De: "Dietmar Maurer" <dietmar at proxmox.com> 
À: "Alexandre DERUMIER" <aderumier at odiso.com>, pve-devel at pve.proxmox.com 
Envoyé: Mercredi 7 Novembre 2012 19:04:38 
Objet: RE: [pve-devel] firsts cache benchs results 

> nexenta - libiscsi: 
> -------------------- 
> default: 4000 (some hangs) 
> cache=none : 14000 
> cache=writeback : 5000 (some hangs) 

I do not really understand that. 

The qemu iscsi.c driver ignore the BDRV_O_NOCACHE flag, so how can this result in any difference?! 

see qemu-kvm/block/iscsi.c