[Samba] Samba and ZFS

Gaiseric Vandal gaiseric.vandal at gmail.com
Wed Aug 4 08:33:30 MDT 2010

the ngroup_max issue isn't specific to an active directory 
environment.    I found with samba 3.0.x, if you were in more than 16 
groups, you might not have all the access you thought you should but you 
could still logon.  (samba didn't check the system ngroups_max.)  With 
samba 3.5.x if you are in more groups than "ngroups_max" you won't even 
be able to logon to windows.

NFS is the limiting factor for ngroups_max.  If you aren't using nfs you 
can up ngroups_max.  Of if you are using nfs with kerberos 
authentication then I think you should also be able to up ngroups_max.   
If you up ngroups_max  and a user has > 16 groups, he would be able to 
login to windows BUT non-krb nfs would be broken.

On 08/04/2010 09:50 AM, Marcis Lielturks wrote:
> Hi!
> You also can run into problems if you have AD environment (workgroup 
> mode could be affected as well btw) and users who are members of more 
> than 16 groups and are using ZFS acls. Faced this problem and could 
> not solve even by compiling samba 3.5.4, adding "ngroups_max=1024" in 
> /etc/system and doing other things.
> On 08/ 4/10 04:44 PM, Gaiseric Vandal wrote:
>> Solaris 10 includes samba 3.0.x with zfs support.   Sun backported 
>> zfs modules from newer sun releases.    If you were to download samba 
>> from www.samba.org you would have to go with 3.4 or 3.5 for the zfs 
>> module.  In the short term, assuming you don't have Vista or Windows 
>> 7 clients and aren't doing domain trusts the Sun bundled version of 
>> Samba should meet your needs.
>> I did have some issues when switching from UFS to ZFS.  ZFS ACL model 
>> is a lot more in line with Windows than UFS ACL's were.   With UFS,  
>> it looked like potential mismatches between Windows and UFS acl's 
>> were ignored.  With ZFS, you are more likely to run into permissions 
>> being enforced inappropriately-  especially with MS Office 
>> documents.    There are various posts in this forum on Solaris 10 
>> (some from me) that address this.
>> You may want to set samba share parameters to include
>>        vfs objects = zfsacl
>>        nfs4: mode = special
>>         nfs4:acedup = merge
>>         nfs4:chown = yes
>>         zfsacl: acesort = dontcare
>> You may also need to set  ZFS permissions to allow the user to 
>> read/write the following
>> a = read_attributes
>> R = read_xattr (exended attibutes)
>> c = read_acl
>> Although you can also set permissions via windows.    You also want 
>> to make sure that setting a file under solaris with  e.g. "660" (ie. 
>> user and group can read and write but no one else can ) doesn't end 
>> up being interpreted by windows clients as "deny access to everyone 
>> even despite rights granted to user or group."
>> I don't actually do quota checking in Windows.   Free space info 
>> seems OK.  But I have several servers with autofs and symlinks under 
>> the samba shared directories so I don't always expect samba directory 
>> info to be correct.    So this may be a cop out but you may need to 
>> setup a test machine to verify for yourself.
>> There are a lot of features in ZFS that are big improvements over 
>> UFS.    Especially if you have RAID5 volumes-  those are really easy 
>> to destroy in UFS if you loose your raid configuration info on the 
>> server.
>> On 08/04/2010 05:54 AM, Martin Rootes wrote:
>>> Hi,
>>>    I've recently moved our student fileserver from a Solaris 10 
>>> server that was using UFS filesytems to a new Sun Cluster. As part 
>>> of the move I decided to employ ZFS for the filesystem so that I 
>>> could take advantage of some of ZFS's features. However, it now 
>>> seems that windows does not report the amount of space that the user 
>>> is actually using, or the amount of quota left, instead it reports 
>>> the total amount of space in use and free on the total filesystem. 
>>> I'm currently running and exceptionally old version of Samba (<3 !) 
>>> and have been planning to upgrade to the latest version of 3 prior 
>>> to the start of term. However, I'm concerned that this may be an 
>>> inherant issue with Samba and ZFS. Will any of the latest versions 
>>> of Samba correctly report a users usage and free space based on 
>>> their quota or am I going to have to look at moving all the data 
>>> back to UFS to get quota reporting working again?
>>>    Martin.

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