[pve-devel] Default cache mode for VM hard drives

[Alexandre DERUMIER]

What is your vm guest os ? kernel version ?
do you have disabled barrier in /etc/fstab ?

What is your host storage ? (soft|hard raid ?)



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

De: "Stanislav German-Evtushenko" <ginermail at gmail.com> 
À: "Dietmar Maurer" <dietmar at proxmox.com>, "Alexandre Derumier" <aderumier at odiso.com> 
Cc: pve-devel at pve.proxmox.com 
Envoyé: Mardi 18 Novembre 2014 17:26:18 
Objet: Re: [pve-devel] Default cache mode for VM hard drives 





Hi Dietmar, hi Alexandre, 



Second, why do you think 'writethrough' is required for DRBD? 




VM drives are often get corrupted when using any mode with write cache enabled. Only directsync and writethrough do not produce the issue. Doesn't matter if DRBD in master-master or master-slave mode. 

Lars Ellenberg explains here why this happens. 


Best regards, 
Stanislav