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

[Cesar Peschiera]

Hi Stanislav

Excuse me please, but your link don't tell me nothing about of the root of 
the problem of "oos" in DRBD (assuming that the directive 
"data-integrity-alg" is disabled).

Also, i have configured in the lvm.conf file "write_cache_state = 0" (may be 
this can help you, that is other recomendation of Linbit)

I think that the tuning of DRBD is the key for the success, that i did in 
workstations and real servers, and never had problems of "oos", always with 
all firmwares of hardware updated and with NICs Intel of 1 Gb/s or 10 Gb/s 
with bonding balance-rr exclusive for replication of DRBD (NIC-to-NIC, and i 
don't know if will work well with the broadcom brand or with other brands, I 
never did a test).

In real servers, with I/OAT engine enabled in the BIOS, and with Intel NICs, 
you get better performance (and in my case, without get  a "oos")

Best regards
Cesar

----- Original Message ----- 
From: Stanislav German-Evtushenko
To: Cesar Peschiera
Cc: Alexandre DERUMIER ; pve-devel
Sent: Monday, April 13, 2015 12:12 PM
Subject: Re: [pve-devel] Default cache mode for VM hard drives


Hi Cesar,


Out of sync with cache=directsync happen in very specific cases. Here is the 
decription of one of them: 
http://forum.proxmox.com/threads/18259-KVM-on-top-of-DRBD-and-out-of-sync-long-term-investigation-results?p=108099#post108099


Best regards,

Stanislav




On Mon, Apr 13, 2015 at 7:02 PM, Cesar Peschiera <brain at click.com.py> wrote:

Hi to all

I use directsync in my VMs with DRBD 8.4.5 in four nodes (LVM on top of 
DRBD), since some months ago, never did have problems (all sunday days, a 
automated system verify all storages DRBD),

These are the version of packages of my PVE nodes:

In a pair of nodes:
Shell# pveversion -v
proxmox-ve-2.6.32: 3.3-139 (running kernel: 3.10.0-5-pve)
pve-manager: 3.3-5 (running version: 3.3-5/bfebec03)
pve-kernel-2.6.32-27-pve: 2.6.32-121
pve-kernel-3.10.0-5-pve: 3.10.0-19
pve-kernel-2.6.32-28-pve: 2.6.32-124
pve-kernel-2.6.32-29-pve: 2.6.32-126
pve-kernel-2.6.32-34-pve: 2.6.32-139
lvm2: 2.02.98-pve4
clvm: 2.02.98-pve4
corosync-pve: 1.4.7-1
openais-pve: 1.1.4-3
libqb0: 0.11.1-2
redhat-cluster-pve: 3.2.0-2
resource-agents-pve: 3.9.2-4
fence-agents-pve: 4.0.10-1
pve-cluster: 3.0-15
qemu-server: 3.3-3
pve-firmware: 1.1-3
libpve-common-perl: 3.0-19
libpve-access-control: 3.0-15
libpve-storage-perl: 3.0-25
pve-libspice-server1: 0.12.4-3
vncterm: 1.1-8
vzctl: 4.0-1pve6
vzprocps: 2.0.11-2
vzquota: 3.1-2
pve-qemu-kvm: 2.1-10
ksm-control-daemon: 1.1-1
glusterfs-client: 3.5.2-1

In other pair of nodes:
Shell# pveversion -v
proxmox-ve-2.6.32: 3.3-139 (running kernel: 3.10.0-5-pve)
pve-manager: 3.3-5 (running version: 3.3-5/bfebec03)
pve-kernel-3.10.0-5-pve: 3.10.0-19
pve-kernel-2.6.32-34-pve: 2.6.32-139
lvm2: 2.02.98-pve4
clvm: 2.02.98-pve4
corosync-pve: 1.4.7-1
openais-pve: 1.1.4-3
libqb0: 0.11.1-2
redhat-cluster-pve: 3.2.0-2
resource-agents-pve: 3.9.2-4
fence-agents-pve: 4.0.10-1
pve-cluster: 3.0-15
qemu-server: 3.3-5 <-particularly made by Alexandre
pve-firmware: 1.1-3
libpve-common-perl: 3.0-19
libpve-access-control: 3.0-15
libpve-storage-perl: 3.0-25
pve-libspice-server1: 0.12.4-3
vncterm: 1.1-8
vzctl: 4.0-1pve6
vzprocps: 2.0.11-2
vzquota: 3.1-2
pve-qemu-kvm: 2.2-2 <-particularly made by Alexandre
ksm-control-daemon: 1.1-1
glusterfs-client: 3.5.2-1