Quanah Gibson-Mount wrote:
--On Tuesday, November 13, 2012 4:25 PM -0800 Howard Chu
<hyc(a)symas.com>
wrote:
>> I found that OSX acts different -- It actually allocates the entire size
>> of the database on disk, regardless of how much is used. That may be
>> common to all the BSDs.
>
> Sounds like whatever filesystem is default on BSDish systems doesn't
> support sparse files.
>
> Anyway, you can use mdb_stat to see what's in the MDB environment.
Oh, one additional note about the BSDs... I didn't see that behavior until
I enabled writemap. Disabling writemap reverted it to the same behavior as
linux, but then of course the advantage of writemap is lost. :P
That's to be expected. When writemap is enabled, we ask the OS to preallocate
the entire map space. Otherwise, writing to a new page would get a SIGBUS.
--
-- Howard Chu
CTO, Symas Corp.
http://www.symas.com
Director, Highland Sun
http://highlandsun.com/hyc/
Chief Architect, OpenLDAP
http://www.openldap.org/project/