[sheepdog] [PATCH v6 0/9] replace structure of inode->data_vdi_id[] from array to b-tree

Liu Yuan namei.unix at gmail.com
Mon Nov 11 10:42:39 CET 2013


On Mon, Nov 11, 2013 at 02:55:26PM +0800, Robin Dong wrote:
> Hi all,
> 
> The size of vdi can only reach 4TB beacause the inode->data_vdi_id[] can only
> support 1 million objects. But 4TB is too small for storage application
> such as NAS and cloud-disk therefore we need to change the array of 'data_vdi_id' to
> b-tree.
> 
> This patchset add B-tree structure into sd_inode. It support just two levels
> (one root-node and many leaf-nodes) and after this the size of vdi could reach about
> (4MB / sizeof(sd_extent_header) * (4MB / sizeof(sd_extent)) * 4MB which is about 680PB
> in theory.
> 
> Currently the vdi size can raise to 16PB because the size of oid is just 32-bits, but
> it is certainly enough for many storage requirement.
> 
> v5 --> v6 changes:
> 	1. add delete_one() support for hyper volume
> 	2. add fill_object_tree() support for hyper volume

Seems that this patch set didn't deal with erasure code. Need to change some
helpers functions like

is_erasure_obj, is_erasure_oid and get_store_objsize in sheep and dog.

Finally make sure we can pass './check -ec'

Thanks
Yuan



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