Before I set up the SS4200 as a backup server for my Apple machines I did some research. The first blog I found was “OpenSolaris ZFS iSCSI Time Machine in 20 Minutes” by Michael Sullivan. The MacOS part worked fine for me. However, Michael uses the package SUNWiscsitgt which seems to be outdated. The current way to export iSCSI devices seems to be COMSTAR. So, what I configured on my SS4200 is COMSTAR and I use the globalSAN iSCSI initiator on Snow Leopard.

Installing Packages on the Server

I needed to install two packages on the server. First the target mode framework (stmf):

master@tank:~# pkg install SUNWstmf
DOWNLOAD                                    PKGS       FILES     XFER (MB)
Completed                                    1/1       36/36     1.03/1.03 

PHASE                                        ACTIONS
Install Phase

Second the iSCSI target provider

master@tank:~# pkg install SUNWiscsit
DOWNLOAD                                    PKGS       FILES     XFER (MB)
Completed                                    2/2       23/23     0.66/0.66 

PHASE                                        ACTIONS
Install Phase

To activate the service stmf I needed to reboot.

Installing globalSAN on Snow Leopard

This step is straight forward. Download globalSAN from here. Install the mpkg from the downloaded DMG.

Starting the iSCSI target provider

The target provider service is named svc:/network/iscsi/target:default. Check if the service is enable and if not enable it.

master@tank:~# svcs -a | grep iscsi
disabled       20:21:19 svc:/network/iscsi/target:default
master@tank:~# svcadm enable -r svc:/network/iscsi/target:default
svcadm: svc:/milestone/network depends on svc:/network/physical, which has
multiple instances.

Per Time Machine Client Setup

You can have multiple devices (aka. logical unit or lu) per iSCSI target. For a Time Machine client you only want one logical unit per target. This way you will only connect the backup volume for the machine in question and no other volume. My experience is that more than one Mac accessing a backup volume at the same time is likely to cause inconsistencies. I had to reinitiate some backup volumes due to multiple logical units on one target.

To start the configuration of targets, stop the stmf service first.

master@tank:~# svcadm disable stmf

For each Mac you want to backup follow these steps:

1. Create a target group. The target group is used to associate the logical unit with the target.

   master@tank:~# stmfadm create-tg electra

2. Create a target.

   master@tank:~# itadm create-target
   Target iqn.1986-03.com.sun:02:f39f064c-9528-c9ff-bd34-f0e0e2c3ccb1
   successfully created

   Remember the target name. You will need it to select the right target when connecting the initiator from the client.

3. Add the target to the target group.

   master@tank:~# stmfadm add-tg-member -g electra \
   iqn.1986-03.com.sun:02:f39f064c-9528-c9ff-bd34-f0e0e2c3ccb1

4. Create a ZFS volume.

   master@tank:~# zfs create -s -V 1G tank/electra

5. Create logical unit for the volume.

   master@tank:~# sbdadm create-lu /dev/zvol/dsk/tank/electra 
   
   Created the following LU:
   
                 GUID                    DATA SIZE           SOURCE
   --------------------------------  -------------------  ----------------
   600144f00220050000004b6dc30e0001      1073676288       /dev/zvol/dsk/tank/electra

   Be sure to use the device in /dev/zvol/dsk not /dev/zvol/rdsk. Remember the GUID. You will need it to connect logical unit and target.

6. Add a view for the logical unit to the target group.

   master@tank:~# stmfadm add-view -t electra 600144f00220050000004b6dc30e0001

   Here you need the GUID again.

After you set up the iSCSI targets for all Time Machine clients you can activate the stmf service again.

master@tank:~# svcadm enable stmf

That’s it on the server side.

Setting up a iSCSI initiator (client) on Snow Leopard

Open the globanSAN preference pane and click on the “+”. Select “Portal”.

Enter the IP address of the iSCSI server.

The discovered targets will appear in the target list. Identify the target you remembered in step 2 above and select it. There will only be one connection. Select it and click “Connect”.

Snow Leopard will discover an uninitialized device. Use diskutil to initialize the device and select it as backup drive in the Time Machine preference pane.

That’s it on the client side. Time Machine should now backup happily over iSCSI.

After OpenSolaris was installed on my SS4200 the next step was to setup the ZFS pool. First you have to decide what kind of data redundancy you need. I started with two disks, but want to be able to increase the capacity by adding a disk at a time. Consequently I decided to go for a raidz which uses one parity disk. A mirror might give more performance in a two disk setup, but the ability to add disk by disk to ramp up the capacity lead to the decision for raidz.

zpool attach pool raidz-vdev device

Creating the zpool

First you need to find out which devices to use for the pool:

master@tank:~# format
Searching for disks...done

AVAILABLE DISK SELECTIONS:
       0. c7d0
          /pci@0,0/pci-ide@1,1/ide@0/cmdk@0,0
       1. c7d1
          /pci@0,0/pci-ide@1,1/ide@0/cmdk@1,0
       2. c8d1
          /pci@0,0/pci-ide@1,1/ide@1/cmdk@1,0
Specify disk (enter its number): ^C

c7d0 is the device the root file system and c7d1 and c8d1 are the empty disks prepared for the pool. Now lets create the pool:

master@tank:~# zpool create tank raidz c7d1 c8d1
master@tank:~# zpool status tank
  pool: tank
 state: ONLINE
 scrub: none requested
config:

        NAME        STATE     READ WRITE CKSUM
        tank        ONLINE       0     0     0
          raidz1    ONLINE       0     0     0
            c7d1    ONLINE       0     0     0
            c8d1    ONLINE       0     0     0

errors: No known data errors

The pool is now up and running as the status output shows.

Creating the file systems and sharing

For creating a file system you simply type:

Sharing the new file system is as easy as:

First of all you need an installation CD for OpenSolaris. I downloaded the current LiveCD from OpenSolaris.org. The SS4200 has no graphic connector and OpenSolaris does not use the console routed through the IDC10 connector. I.e. you cannot see the output once the LiveCD has started. To know what keys I had to press to choose the write start configuration from the grub menu I started the LiveCD in a VirtualBox instance. In short: Push 4x cursor down and hit enter. This way the LiveCD starts with SSH active.

To start the SS4200 with the LiveCD I burned it to a real CD and put it into an USB-CD-ROM-drive. I connected the drive to the box. I made sure the USB-stick I wanted to install OpenSolaris onto was not connected. Next I connected the terminal application on my MacBook with the RS232 connector of the SS4200. See my previous blog for more information. Additionally I connected an USB-keyboard.

Boot and Install

Pressing the power button starts up the device. To boot from the LiveCD I held down F3 on the keyboard. This led to a menu appearing on my terminal with a choice of boot disks. I choose the USB-CDROM-drive. The LiveCD booted and the copyright notice followed on the terminal – no more messages on this way. After about a minute I entered the 4x cursor down and hit enter. Some two minutes later I was able to ping the box and log in via SSH:

Next, I connected the USB-stick and started the installation:

The installation process went on straight forward. I just followed the instructions. After reboot and holding down F3 again, I chose the USB-stick as boot device. After another minute the system was up and reachable via SSH.

The SS4200 gets delivered with no power cable. Luckily I had a stock of such cables from the computers a owned so far. What I found remarkable is the way the hard-disks are mounted in the case. There are four bays that each take one disk. The bays have brackets that – when closed – form a rail with the bottom of the bay. Also in the packet are some bolts with rubber tops – shown to the left – that fit in the rails and thus secure the drives in the bays. The rubber top the noise-reducing decoupling of the drives from the case.

Adding the Disks

To get the disks mounted you follow some simple steps:

• Put four bolts in each disk
• Open the securing bolt of the disk bay
• Open the bay
• Connect power supply and SATA plug
• Place disk inside the bay
• Close drive bay
• Tighten securing bolt

Getting Access

The SS4200 has no graphic connector. The only way to get access to the BIOS is thru a serial console. On the main-board is an IDC10 connector which provides the RS232 interface. I used a ready-made IDC10 to DB9 adapter from the local electronics store. I also needed a USB to serial adapter and a null modem to connect the DB9 plug to my Macbook. The USB to serial adapter turned out to be a PI2303 by Prolific.

I followed the instructions here and installed the driver from here. To connect to the SS4200 you then just type: