--On Tuesday, November 13, 2012 4:54 PM -0800 Howard Chu <hyc(a)symas.com>
Quanah Gibson-Mount wrote:
> --On Tuesday, November 13, 2012 4:25 PM -0800 Howard Chu <hyc(a)symas.com>
>>> 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.
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.
That's not quite what I see.
On Linux, you get:
[zimbra@ldap01-zcs db]$ ls -l
-rw------- 1 zimbra zimbra 85899345920 Nov 13 17:23 data.mdb
-rw------- 1 zimbra zimbra 8192 Nov 13 17:23 lock.mdb
[zimbra@ldap01-zcs db]$ du -c -h data.mdb
But on OSX, the du -c -h shows 80GB as well.
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