[sheepdog] [PATCH v4] sheepdog: selectable object size support
ishizaki.teruaki at lab.ntt.co.jp
Wed Feb 4 05:54:19 CET 2015
(2015/02/02 15:52), Liu Yuan wrote:
> On Tue, Jan 27, 2015 at 05:35:27PM +0900, Teruaki Ishizaki wrote:
>> Previously, qemu block driver of sheepdog used hard-coded VDI object size.
>> This patch enables users to handle "block_size_shift" value for
>> calculating VDI object size.
>> When you start qemu, you don't need to specify additional command option.
>> But when you create the VDI which doesn't have default object size
>> with qemu-img command, you specify block_size_shift option.
>> If you want to create a VDI of 8MB(1 << 23) object size,
>> you need to specify following command option.
>> # qemu-img create -o block_size_shift=23 sheepdog:test1 100M
> Is it possible to make this option more user friendly? such as
> $ qemu-img create -o object_size=8M sheepdog:test 1G
At first, I thought that the object_size was user friendly.
But, Sheepdog has already the value of block_size_shift
in the inode layout that means like object_size.
'object_size' doesn't always fit right in 'block_size_shift'.
On the other hands, 'block_size_shift' always fit right in
I think that existing layout shouldn't be changed easily and
it seems that it is difficult for users to specify
the object_size value that fit right in 'block_size_shift'.
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