The Blog of Ed Plese

This is a quick guide for setting up a CIFS/SMB file server using Samba within a virtualized zone on SmartOS.  A couple of the many benefits of doing this on SmartOS are that it can utilize ZFS for file storage and also that the file server can be isolated off as a zone and be run in parallel with various other zones and virtual machines.

On to the setup steps…

1. From an installed and running SmartOS system setup a JSON config file for the zone.  I tend to create a directory /opt/vmcfg and place the file there, in this case named samba01.json with the following contents.  When placed in a directory under /opt the files will persist across system reboots.  This sample config uses the base-64 15.1.1 image.  The delegate_dataset=true creates a ZFS filesystem that can be managed within the zone which is a nice feature to have on a file server for separating out users or shares to different filesystems.  The alias, hostname, quota, max_physical_memory, ZFS compression, and network configuration can be updated to your environment.

   {
     "brand": "joyent",
     "alias": "samba01",
     "hostname": "samba01",
     "quota": 50,
     "image_uuid": "0edf00aa-0562-11e5-b92f-879647d45790",
     "max_physical_memory": 1024,
     "delegate_dataset": true,
     "zfs_data_compression": "on",
     "zfs_root_compression": "on",
     "dns_domain": "local",
     "resolvers": [
       "8.8.8.8",
       "8.8.4.4"
     ],
     "nics": [
       {
         "nic_tag": "admin",
         "ip": "10.1.1.211",
         "netmask": "255.255.255.0",
         "gateway": "10.1.1.1",
         "primary": true
       }
     ]
   }
   

2. Create the zone from the configuration file.

   # vmadm create -f samba01.json 
   Successfully created VM 6153d789-5697-4ec6-a237-55198fe3c6b8
   

3. Log into the zone and install Samba.

   # zlogin 6153d789-5697-4ec6-a237-55198fe3c6b8
   # pkgin update
   # pkgin install samba
   

4. Setup the ZFS home directories and move the admin user home directory to a ZFS filesystem.

   # zfs create zones/6153d789-5697-4ec6-a237-55198fe3c6b8/data/home
   # zfs create zones/6153d789-5697-4ec6-a237-55198fe3c6b8/data/home/admin
   # cp -a /home/admin/. /zones/6153d789-5697-4ec6-a237-55198fe3c6b8/data/home/admin
   # rm -rf /home/admin
   # zfs set mountpoint=/home zones/6153d789-5697-4ec6-a237-55198fe3c6b8/data/home
   

5. Create a new user with a separate filesystem for the home directory.

   # zfs create zones/6153d789-5697-4ec6-a237-55198fe3c6b8/data/home/ed
   # chown ed:other /home/ed
   # useradd ed
   

6. Set the user’s Samba password.

   # smbpasswd -a ed
   

7. Optionally edit the Samba config file in /opt/local/etc/samba/smb.conf.
8. Start up Samba.  This will also set it to be enabled at startup.

   # svcadm enable -r smbd
   # svcadm enable -r nmbd

9. From a Windows or other computer connect to the user’s home directory/share as \\10.1.1.211\ed

This will get you a basic file server setup.  From here you can add addition users, shared directories, etc.

A few weeks ago there was a thread on the Samba mailing list regarding some difficulties in getting my shadow copy patches to work with newer versions of Samba.  These patches were originally written for Samba 3.0.25, and since then, Samba has moved up to version 3.4.3, with the 3.5.0 release on the horizon.  The more recent Samba versions also include a shadow_copy2 module that will likely be replacing the shadow_copy module in the future.

I spent some time today adapting the original patches to the shadow_copy2 module.  This patch was made against Samba 3.4.3, and I will be working on a version for Samba 3.5.x over the next couple days.  I hope to get this integrated into Samba, but for now, it’s available below:

• samba-3.4.3-shadowcopy.patch.gz

Creating a patched Samba source tree can be done with:

$ gzcat samba-3.4.3.tar.gz | tar -xf -
$ cd samba-3.4.3
$ gzcat ../samba-3.4.3-shadowcopy.patch.gz | patch -p1

The parameters added with this patch, as shown at the top of the source file, are:

shadow:sort = asc/desc, or blank for unsorted (default)

This is an optional parameter that specifies that the shadow
copy directories should be sorted before sending them to the
client.  This is beneficial for filesystems that don't read
directories alphabetically (e.g. ZFS).  If enabled, you typically
want to specify descending order.

shadow:format = <format specification for snapshot names>

This is an optional parameter that specifies the format
specification for the naming of snapshots.  The format must
be compatible with the conversion specifications recognized
by str[fp]time.  The default value is "@GMT-%Y.%m.%d-%H.%M.%S".

shadow:localtime = yes/no (default is no)

This is an optional parameter that indicates whether the
snapshot names are in UTC/GMT or the local time.

Example usage with ZFS for the [homes] share is:

[homes]
   comment = Home Directories
   browseable = no
   writable = yes
   vfs objects = shadow_copy2
   shadow: snapdir = .zfs/snapshot
   shadow: sort = desc
   shadow: localtime = yes
   shadow: format = %Y%m%d-%H%M%S

Where the snapshots would be taken with:

# zfs snapshot -r tank/home@`date +%Y%m%d-%H%M%S`

Recent versions of OpenSolaris allow ZFS snapshots to be created remotely over SMB/CIFS by simply creating a directory in the .zfs/snapshot subdirectory.  To see how this can be used, see my Windows Backups to ZFS post.  Though referring to the SMB/CIFS server built into OpenSolaris, the concept works equally as well with Samba and the shadow copy patch.