On 10/31/2012 06:19 AM, Hugo Mills wrote:

On Tue, Oct 30, 2012 at 10:14:12PM +0000, Hugo Mills wrote:

quoted

On Wed, Oct 31, 2012 at 05:40:25AM +0800, ching wrote:

quoted

On 10/30/2012 08:17 PM, cwillu wrote:

quoted

quoted

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If there is a lot of small files, then the size of metadata will be
undesirable due to deduplication

Yes, that is a fact, but if that really matters depends on the use-case
(e.g., the small files to large files ratio, ...). But as btrfs is designed
explicitly as a general purpose file system, you usually want the good
performance instead of the better disk-usage (especially as disk space isn't
expensive anymore).

As I understand it, in basically all cases the total storage used by
inlining will be _smaller_, as the allocation doesn't need to be
aligned to the sector size.

if i have 10G small files in total, then it will consume 20G by default.

   If those small files are each 128 bytes in size, then you have
approximately 80 million of them, and they'd take up 80 million pages,
or 320 GiB of total disk space.

   Sorry, to make that clear -- I meant if they were stored in Data.
If they're inlined in metadata, then they'll take approximately 20 GiB
as you claim, which is a lot less than the 320 GiB they'd be if
they're not.

   Hugo.

is it the same for:
1. 3k per file with leaf size=4K
2. 60k per file with leaf size=64k