It can. I have seldom had need to worry about it. Most data centers have
battery backups to keep power outages from crashing systems. I am also not
sure if its any more or less of a risk than iscsi, except you may not be
able to tell right away. async works by basically lying to the client
about the read/write. Keep in mind that the read/write may be into a
virtual machine in this case. Even if all packets are accounted for, not
completing the full stream of writing could lead to a corrupt VM filesystem
anyway. In my mind, its worth the risk for the speed. This is also why we
do backups.
On Fri, Mar 23, 2012 at 7:48 AM, Morgan Cox <morgancoxuk(a)gmail.com> wrote:
Thank you Gary.
After re-mounting the NFS share with async it dramatically increased the
speed !
I can now create a 10GB virtual disk in 2 mins (rather than 10 mins)
Is using the async option more likely to cause data corruption though ?
Many thanks
Regards
On 22 March 2012 21:54, Gary Scarborough <virtuallymad(a)gmail.com> wrote:
>
>
> On Thu, Mar 22, 2012 at 12:59 PM, Morgan Cox <morgancoxuk(a)gmail.com>wrote:
>
>> Hi.
>>
>> After my many issues with spice I have finally sorted them out.
>>
>> Now I am having an issue with the speed of virtual disk creation - when
>> I go to create a virtual disk it takes a long time (far to long to
>> be usable)
>>
>> My setup is as following
>>
>> 3 servers:-
>>
>> 1 Frontend (ovirt engine) - Fedora 16 - external + local IP
>> (91.215.xxx.xx + 10.0.0.10)
>> 1 Ovirt node (using the node .iso) - external + local IP (ovirtmgmt
>> (eth0) - 91.215.xxx.xxx and LAN (eth1) - 10.0.0.101)
>> 1 NFS storage - external + local IP - I attached the storage using the
>> Local IP (10.0.0.190)
>>
>> All servers are connected via a Gigabit switch (so speed should be
>> better)
>>
>> I can scp between servers far faster - I'm almost sure its due to the
>> node ovirtmgmt address being an external (internet ip) and not LAN ip.
>> - therefore the traffic is not just going over the gigabit switch but via
>> the core router in the DC...
>>
>> Can anyone suggest how I can 'debug' where the slowness is coming from
>>
>> On my NFS server I have it setup like (in /etc/exports)
>>
>> /storage1 *(rw,sync,no_subtree_check)
>>
>> I had previous tried setting up the node on a LAN IP previously and it
>> caused spice to not work - as the node had no internet access / DNS - I
>> also tried making the frontend server a gateway (and using - iptables -t
>> nat -A POSTROUTING -j MASQUERADE ) - this also cause spice to not work (as
>> it always tried to connect to the 10.0.0.x address from my desktop - and
>> fail..)
>>
>> Any hints/help will be welcomed
>>
>> Cheers
>>
>>
>>
>> _______________________________________________
>> Users mailing list
>> Users(a)ovirt.org
>>
http://lists.ovirt.org/mailman/listinfo/users
>>
>>
> You could try async instead of sync. You could also try thin
> provisioning.
>
> --
> Gary Scarborough
> IST Lab Manager
> Rochester Institute of Technology
> Rochester NY
>
--
Gary Scarborough
IST Lab Manager
Rochester Institute of Technology
Rochester NY