[pve-devel] qemu-server: add directsync cache mode

[Alexandre DERUMIER]

yes, maybe "slow - secure" .



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

De: "Dietmar Maurer" <dietmar at proxmox.com> 
À: "Alexandre DERUMIER" <aderumier at odiso.com> 
Cc: pve-devel at pve.proxmox.com 
Envoyé: Mardi 10 Avril 2012 09:31:36 
Objet: RE: [pve-devel] qemu-server: add directsync cache mode 

> It's do a fsync on each write to be sure to not loose a single transaction. 
> could be usefull for database by exemple, where we don't have to use host 
> cache. 

So maybe we should add a hint to the GUI that this is extremely slow? 

> Also,some older linux (or "old" filesystem, could corrupt with cache="none" or 
> cache"writeback", as they dont send flush command. 
> 
> 
> some infos: 
> http://lists.fedoraproject.org/pipermail/virt/2011-October/002956.html 
> 
> 
> >> But why do we want to have a workaround for that? 
> I just want to add all cache mode available in qemu. Maybe some users want it . 

OK 

> If I have time, I think i'll write a wiki article about cache options, as it's not 
> simple to understand how they works. 

That would be great. 

- Dietmar 



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