Samba4: LDB size limit and memory leak

Marcel Ritter Marcel.Ritter at
Mon May 25 07:23:45 GMT 2009

Andrew Bartlett schrieb:
> On Mon, 2009-05-25 at 08:30 +0200, Marcel Ritter wrote:
>> Hi,
Hi Andrew,
>> I'm running several samba 4 tests at the moment and I found two things,
>> that may need some attention:
>> 1. LDB size seems to be limited to 4GB (both on i586 and x86_64). I tried
>>     to create a lot of new users using setup/newuser and somewhere in
>> between
>>     20000 and 40000 users, setup/newuser crashes:
> Correct.  If a 64 bit varient of TDB were developed, that limit would be
> removed.
So TDB is 32-bit only right now?

In bugzilla I found something about a 64-bit Patch to TDB, but it's quite
outdated (from 2005):

Any hint what needs to be done to make it 64-bit capable?
>>    The resulting filesize of users.ldb is exactly 4GB + 4096 bytes
>> (4294971392 bytes)
>> 2. As mentioned above I used setup/newuser to create the samba4 users. To
>>     speed things up a little I tried to modify newuser to internally
>> loop over
>>     function "samdb.newuser(username, opts.unixname, password)".
>>     However the amount of memory needed increases dramatically when using
>>     this version (and finally the python process dies when out of memory).
>>     I also tried to loop over a "less demanding" function like
>> "samdb.domain_dn()"
>>     with the same effect on memory consumption.
>>     Looks like a memory leak to me.
> It is quite possible that the python code has not recovered the moment
> at this point.  
> What version are you working with?
I'm using a one week old samba git checkout for testing.
> We have significantly improved ldb's memory use and disk space
> requirements in the past few months. 
> Andrew Bartlett

Dipl.-Inf. Marcel Ritter
Unix _IS_ user friendly... It's just selective about who its friends are.

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