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From Marcus <shadow...@gmail.com>
Subject Re: [RFC] adding volume provisioning method option
Date Sat, 01 Feb 2014 06:01:14 GMT
I don't think preallocation=metadata is required for sparse qcow2.
Just if you want it to NOT be sparse for metadata.

I also remember hearing that either recent qemu-img has a decent
preallocation by default now, or that performance has improved such
that it doesn't matter. Will need to do some reading to remember, but
I think I remember hearing it's not a big deal nowadays.

On Fri, Jan 31, 2014 at 10:04 PM, Yoshikazu Nojima <mail@ynojima.net> wrote:
> Hello Nux,
>
> Thank you for your comment. I will prepare feature specification.
>
> Regards,
>
> 2014-01-31 Nux! <nux@li.nux.ro>:
>> On 31.01.2014 20:24, Yoshikazu Nojima wrote:
>>>
>>> Afternoon All,
>>>
>>> Is there anyone working on adding volume provisioning method option?
>>> As you know, thin provisioning of a volume save consumption of a
>>> storage, and fat provisioning improves IOPS performance.
>>> Especially, Qcow2 can save storage consumption and achive relatively
>>> better performance than default by provisioning a volume with an
>>> option "preallocation=metadata", which makes an image file a sparse
>>> file.
>>>
>>> http://itscblog.tamu.edu/improve-disk-io-performance-in-kvm/#.232---preallocation
>>>
>>> Any thoughts about this?
>>> If it is ok, I will write a feature specification on confluence and
>>> start implementation.
>>>
>>> Regards,
>>> Noji
>>>
>>>
>>> Yoshikazu Nojima <mail@ynojima.net>
>>
>>
>> Hello,
>>
>> I thought preallocation=metadata is common practice since years. Now I find
>> out ACS doesn't actually use it?
>> If so, this is really _bad_ and needs to be fixed ASAP...
>>
>> Thanks Noji
>>
>> --
>> Sent from the Delta quadrant using Borg technology!
>>
>> Nux!
>> www.nux.ro

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