Kerning comparison OSX – Windows – TLF

I did some tests comparing the same text on OS X with the TextEdit, on Windows XP with WordPad and on OS X in Safari on the Adobe Text Layout Framework demo site. I used everywhere Times New Roman as the font and a font size of 28.
Although Windows does not use kerning the text looks almost the same with some pixel difference. Have a look for yourself:
Comparing a text on OSX, Windows XP and TLF


Setting up an OpenSolaris root server at Hetzner

Several months ago I ordered a root server by the German hosting provider Hetzner called EQ4. It is quite powerful: an Intel Core i7-920 Quad-Core CPU, 8 GB RAM and two 750 GB HDDs for only 45,- €/month. Since they only provide several Linux flavors (openSuSE, Fedora, CentOS) at first glance I decided to use CentOS. I already some very good experiences with it a couple of years ago. The installation process was very easy.

After a couple of months without much time to fiddle with the server it just sat there in its rack and got bored.

After the very inspiring NoSQL meeting in Berlin last Thrusday I decided to spend some time with my server installing Erlang, CouchDB and nginx as a reverse proxy to do authentication and SSL stuff.

Installing the software packages went very well. Some of them I grabbed via yam others I installed from source. Connecting to my system via a ssh session worked very well but there was a very strange iptables setup in the CentOS installation which drove me crazy. I could not reach the proxy from outside and after several hours I decided to try a reinstall. At Hetzner one can reboot the server in a so called rescue mode. This mode can be of course Linux, but also FreeBSD and OpenSolaris. Digging a little further I discovered a site in the Hetzner wiki describing how to install OpenSolaris through this rescue system.

I used JollyFastVNC to establish a VNC session to the rescue system and used the graphical OpenSolaris installer to install it on the first HDD. After installation I used my directions from an earlier post to create a ZFS mirror using both HDDs.

This is my hardware configuration discovered by OpenSolaris:

# prtdiag -v
System Configuration: MSI MS-7522
BIOS Configuration: American Megatrends Inc. V8.2 04/20/2009

==== Processor Sockets ====================================

Version                          Location Tag
-------------------------------- --------------------------
Intel(R) Core(TM) i7 CPU         920  @ 2.67GHz CPU 1

==== Memory Device Sockets ================================

Type        Status Set Device Locator      Bank Locator
----------- ------ --- ------------------- ----------------
other       in use 0   DIMM0               BANK0
other       in use 0   DIMM1               BANK1
other       in use 0   DIMM2               BANK2
other       empty  0   DIMM3               BANK3
other       in use 0   DIMM4               BANK4
other       empty  0   DIMM5               BANK5
FLASH       in use 0                        

==== On-Board Devices =====================================

==== Upgradeable Slots ====================================

ID  Status    Type             Description
--- --------- ---------------- ----------------------------
1   available PCI              PCI1
2   available PCI Express      PCIE2
3   available PCI Express      PCIE3
4   available PCI Express      PCIE4

Next I used the CouchDB directions in the Joyent Wiki to install the entire required software stack from source. After some fiddling with directory write permissions I had my CouchDB system up and running.

To install nginx I used the official site. I wanted to have a password authentication on my site. Since nginx doesn’t come with htpasswd I used it on my Mac:

$ htpasswd -nbd user password

I copied the output line into the file /etc/nginx/htpasswd on my server.

To create a self signed certificate in the folder /etc/nginx I used the following commands:

# openssl req -new -nodes -keyout selfsigned.key -out selfsigned.csr
Generating a 1024 bit RSA private key
writing new private key to 'selfsigned.key'
# openssl x509 -req -days 1095 -in selfsigned.csr -signkey selfsigned.key -out selfsigned.crt
Signature ok
Getting Private key

My nginx setup file contents are:


#user  nobody;
worker_processes  2;

#error_log  logs/error.log;
#error_log  logs/error.log  notice;
#error_log  logs/error.log  info;

#pid        logs/;

events {
    worker_connections  1024;

http {
    include       mime.types;
    default_type  application/octet-stream;

    #log_format  main  '$remote_addr - $remote_user [$time_local] $request '
    #                  '"$status" $body_bytes_sent "$http_referer" '
    #                  '"$http_user_agent" "$http_x_forwarded_for"';

    #access_log  logs/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    #keepalive_timeout  0;
    keepalive_timeout  65;

    #gzip  on;

    server {
        listen       80;
        server_name  localhost;

        #charset koi8-r;

        #access_log  logs/host.access.log  main;

        location / {
                auth_basic "Restricted";
                auth_basic_user_file /etc/nginx/htpasswd;
                rewrite /couchdb/(.*) /$1 break;
                proxy_pass http://localhost:5984;
                proxy_redirect off;
                proxy_set_header Host $host;
                proxy_set_header X-Real-IP $remote_addr;
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

        #error_page  404              /404.html;

        # redirect server error pages to the static page /50x.html
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;

    # HTTPS server
    server {
        listen       443;
        server_name  localhost;

        ssl                  on;
        ssl_certificate      /etc/nginx/selfsigned.crt;
        ssl_certificate_key  /etc/nginx/selfsigned.key;

        ssl_session_timeout  5m;

        ssl_protocols  SSLv2 SSLv3 TLSv1;
        ssl_ciphers  ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP;
        ssl_prefer_server_ciphers   on;

        location / {
                auth_basic "Restricted";
                auth_basic_user_file /etc/nginx/htpasswd;
                rewrite /couchdb/(.*) /$1 break;
                proxy_pass http://localhost:5984;
                proxy_redirect off;
                proxy_set_header Host $host;
                proxy_set_header X-Real-IP $remote_addr;
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

Now when I open http://my.secret.server.ipaddress/ I can log in with the created user credentials stored in htpasswd and get the warm CouchDB welcome message: ‘{“couchdb”:”Welcome”,”version”:”0.10.0″}’. I can also use the secure entry at https://my.secret.server.ipaddress/.

After every successful step I made a ZFS snapshot which is the greatest feature I can use now. By the way: a nice ZFS cheat sheet can be found here.

I don’t know why it worked so well with OpenSolaris and I had so many problems with CentOS. Maybe my system is now wide open and completely insecure, but this way I like it much better because now I can close all the open doors step by step and make it more secure.

Next I will move my domain also to Hetzner and let it point to my server. Then I will setup a mail server, maybe install some Ruby on Rails stuff ( and will write an Adobe Flex application for a customer which will rely completely on CouchDB #bliss.

Setting up my Solaris server as a centralized backup server

After some months of work I now have the time to set-up my server properly so that it can backup all my computers without a hassle. Since I wanted to let the server control, when the backups should be made I wrote a Ruby script which runs every hour and backs up all the available hosts (which are of course Macs ;-). The script should not run at the same time and produce a decent logfile.

Set up environment

First I had to make sure, that the server had the correct time. By default the ntp daemon did not run, so I configured it using the description at the grey blog. I did not use the European ntp server though instead I used

To install the current version 1.8.7 of Ruby I entered as root:

# pfexec pkg install SUNWruby18

Then I created a ssh key for my Solaris root user:

# ssh-keygen -t dsa
Enter file in which to save the key (/root/.ssh/id_dsa):
Created directory '/root/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_dsa.
Your public key has been saved in /root/.ssh/
The key fingerprint is:

To get a ssh connection which is needed for rsync to each of my hosts I then copied the contents of /root/.ssh/ to the to the file authorized_keys e.g. user1@host1:.ssh/authorized_keys

Now whenever I enter “ssh user1@host1” no password is needed to get a remote shell.

The Ruby Script

# This script will fetch the current files from a couple of hosts via rsync
# and stores them locally
require 'ping'
require 'tempfile'
require 'open3'
require 'logger'
require 'fileutils'


# Parse the commandline parameters
ARGV.each do |arg|
  when arg == '--stdout'
    LOG_STDOUT = true
  when arg == '--dry-run'
    DRY_RUN = true
LOG_STDOUT = (LOG_STDOUT rescue false) # Set default value to false
DRY_RUN = (DRY_RUN rescue false)       # dto.

# Check which output should be used for logging
  # Log to stdout
  $LOG =$stdout)
  $LOG.datetime_format = '%H:%M:%S'
  # Logfile will not exceed 1 MB
  $LOG ='/var/log/backup_rb.log', 0, 1 * 1024 * 1024)
  $LOG.datetime_format = '%d.%m.%y %H:%M:%S'

# Kill older processes of this script
pids_to_kill = []
`ps -Al -o pid -o args|grep -e ruby|grep -e #{__FILE__}`.split("\n").each do |line|
  other_pid = line.split(" ")[0].to_i
  if other_pid != $$
    pids_to_kill << other_pid
    `ps -Al -o pid,ppid=MOM -o args|grep "1 rsync"|grep -v grep`.split("\n").each do |child_line|
      child_pid = child_line.split(" ")[0].to_i
      pids_to_kill << child_pid

if pids_to_kill.length > 0
  $ "****** Cleaning up... *******"
  $ "Killing old backup processes #{pids_to_kill.join(",")}"
  `kill -9 #{pids_to_kill.join(" ")}`

# Execute a command and store its output
class ExecCmd
  attr_reader :output,:error_output,:cmd,:exec_time

  def initialize(cmd,cmd_id)
    @output = ""
    @error_output = ""
    @exec_time = 0
    @cmd = cmd
    @cmd_id = cmd_id

  def run
    start_time =
      $ "[#{@cmd_id}] Starting command: #{@cmd}..."
      Open3.popen3(@cmd) do |stdin, stdout, stderr|
        @output =
        @error_output =
    rescue Exception => e
      @error_output += e.to_s
      @exec_time = - start_time
      $ "[#{@cmd_id}] Command completed in #{@exec_time} seconds."

  # Log the stdio and stderr outputs
  def log_results
    $ "[#{@cmd_id}] #{@cmd}:"
    if @error_output.length > 0
      @error_output.split("\n").each { |line| $LOG.error "[#{@cmd_id}]  #{line}" }
    if @output.length > 0
      @output.split("\n").each { |line| $ "[#{@cmd_id}]  #{line}" }

  # Returns false if the command hasn't been executed yet
  def run?
    return @exec_time > 0

  # Returns true if the command was successful.
  def success?
    return @error_output.length == 0

# Define for each host which user accounts are being backed up and which files should be excluded
default_excludes = ['.Trash', 'Downloads', 'Desktop', 'Music/iTunes/iTunes Music/Podcasts',
                    'Library/Caches', 'Library/Logs']
# format: hostname => { username => [excluded_files] }
HOSTS={ 'host1' => { 'user1' => default_excludes },
        'host2' => { 'user2' => default_excludes, 'user1' => default_excludes },
        'host3' => { 'user2' => default_excludes + ['Music/iTunes']},
        'host4' => { 'user3' => default_excludes }

$ "****** Backup started... *******"

# Make a ZFS snapshot
snapshot_name = "#{ZFS_POOL}@backup-#{'%y-%m-%d_%H:%M')}"
$ "Creating ZFS snapshot #{snapshot_name}"
`zfs snapshot #{snapshot_name}`

pending_commands = {}
HOSTS.each do |hostname,user_data|
  $ "Calling #{hostname} ..."
  if Ping.pingecho(hostname)
    user_data.each do |user,excluded_files|
      exclude_file ="tempfile")
      excluded_files.each { |filepath| exclude_file << filepath << "\n" }
      user_hostname = "#{user}@#{hostname}"
      $ "Backing up #{user_hostname} ..."
      local_backup_path = "#{LOCAL_BACKUP_PATH}/#{hostname}/#{user}"
      FileUtils.mkdir(local_backup_path) unless File.exists? local_backup_path
      command = "rsync -#{DRY_RUN ? 'n' : ''}avz --delete --partial --exclude-from=#{exclude_file.path} #{user_hostname}: #{local_backup_path}/"
      rsync =, user_hostname)
      pending_commands[user_hostname] = rsync do
    $LOG.warn "#{hostname} does not respond!"

# Wait for the backup processes to complete
while pending_commands.length > 0
  pending_commands.each do |user_hostname, exec_cmd|

  if pending_commands.length > 0
    $ "Still #{pending_commands.length} tasks backing up #{pending_commands.keys.join(', ')}"
    sleep 60

$ "****** Backup complete. *******\n"

What it does

You can use the command line argumens –dry-run and –stdout. The first one will call rsync with the –dry-run option and the second one will write to stdout instead of a logfile.

On start the script looks for other instances of itself and will kill them and all orphaned rsync child processes.

It will create a ZFS snapshot of the target pool with the current time and date as a label.

Then it will ping all the hosts defined in HOSTS and will construct the rsync command with all the excluded files and the defined users and start a separate thread in which the command will be executed.

Then it will loop until all the rsync tasks have been completed.

The logfile is /var/log/backup_rb.log and looks like this:

I, [15.10.09 11:44:11#7343]  INFO -- : ****** Cleaning up... *******
I, [15.10.09 11:44:11#7343]  INFO -- : Killing old backup processes 7316,7325,7332,7328,7334
I, [15.10.09 11:44:11#7343]  INFO -- : ****** Backup started... *******
I, [15.10.09 11:44:11#7343]  INFO -- : Creating ZFS snapshot daten@backup-09-10-15_11:44
I, [15.10.09 11:44:11#7343]  INFO -- : Calling host1 ...
I, [15.10.09 11:44:11#7343]  INFO -- : Backing up user2@host1 ...
I, [15.10.09 11:44:11#7343]  INFO -- : [user2@host1] Starting command: rsync -avz --delete --partial --exclude-from=/tmp/tempfile20091015-7343-1hpu6rm-0 user2@host1: /daten/host1/user2/...
I, [15.10.09 11:44:11#7343]  INFO -- : Calling host2 ...
I, [15.10.09 11:44:11#7343]  INFO -- : Backing up user1@host2 ...
I, [15.10.09 11:44:11#7343]  INFO -- : [user1@host2] Starting command: rsync -avz --delete --partial --exclude-from=/tmp/tempfile20091015-7343-1f9jzvu-0 user1@host2: /daten/host2/user1/...
I, [15.10.09 11:44:11#7343]  INFO -- : Calling host3 ...
W, [15.10.09 11:44:16#7343]  WARN -- : host3 does not respond!
I, [15.10.09 11:44:16#7343]  INFO -- : Calling host4 ...
I, [15.10.09 11:44:16#7343]  INFO -- : Backing up user2@host4 ...
I, [15.10.09 11:44:17#7343]  INFO -- : [user2@host4] Starting command: rsync -avz --delete --partial --exclude-from=/tmp/tempfile20091015-7343-yv60ta-0 user2@host4: /daten/host4/user2/...
I, [15.10.09 11:44:17#7343]  INFO -- : Backing up user1@host4 ...
I, [15.10.09 11:44:17#7343]  INFO -- : [user1@host4] Starting command: rsync -avz --delete --partial --exclude-from=/tmp/tempfile20091015-7343-644sq6-0 user1@host4: /daten/host4/user1/...
I, [15.10.09 11:44:17#7343]  INFO -- : Still 4 tasks backing up user1@host2, user1@host4, user2@host4, user2@host1
I, [15.10.09 11:45:17#7343]  INFO -- : Still 4 tasks backing up user1@host2, user1@host4, user2@host4, user2@host1
I, [15.10.09 11:45:41#7343]  INFO -- : [user2@host4] Command completed in 84.087238
I, [15.10.09 11:46:17#7343]  INFO -- : [user2@host4] rsync -avz --delete --partial --exclude-from=/tmp/tempfile20091015-7343-yv60ta-0 user2@host4: /daten/host4/user2/:
I, [15.10.09 11:46:17#7343]  INFO -- : [user2@host4] receiving file list ... done
I, [15.10.09 11:46:17#7343]  INFO -- : [user2@host4] Dropbox/
I, [15.10.09 11:46:17#7343]  INFO -- : [user2@host4] Library/Application Support/SyncServices/Local/
I, [15.10.09 11:46:17#7343]  INFO -- : [user2@host4] Library/Application Support/SyncServices/Local/admin.syncdb
I, [15.10.09 11:46:17#7343]  INFO -- : [user2@host4] Library/Application Support/SyncServices/Local/TFSM/
I, [15.10.09 11:46:17#7343]  INFO -- : [user2@host4] Library/Application Support/SyncServices/Local/clientdata/120c2b27e9ab530b442181ced8799e35b30c85cb/
I, [15.10.09 11:46:17#7343]  INFO -- : [user2@host4] Library/Application Support/SyncServices/Local/conflicts/
I, [15.10.09 11:46:17#7343]  INFO -- : [user2@host4] Library/Calendars/
I, [15.10.09 11:46:17#7343]  INFO -- : [user2@host4] Library/Calendars/Calendar Cache
I, [15.10.09 11:46:17#7343]  INFO -- : [user2@host4] Library/Calendars/Calendar Sync Changes/
I, [15.10.09 11:46:17#7343]  INFO -- : [user2@host4] Library/Calendars/FE3DF9D9-8D76-4F44-973A-525E02717BFE.calendar/Info.plist
I, [15.10.09 11:46:17#7343]  INFO -- : [user2@host4] Library/Logs/Sync/syncservices.log
I, [15.10.09 11:46:17#7343]  INFO -- : [user2@host4] Library/Mail/
I, [15.10.09 11:46:17#7343]  INFO -- : [user2@host4] Library/Preferences/
I, [15.10.09 11:46:17#7343]  INFO -- : [user2@host4] Library/Preferences/iCalExternalSync.plist
I, [15.10.09 11:46:17#7343]  INFO -- : [user2@host4]
I, [15.10.09 11:46:17#7343]  INFO -- : [user2@host4] sent 13772 bytes  received 1001023 bytes  13440.99 bytes/sec
I, [15.10.09 11:46:17#7343]  INFO -- : [user2@host4] total size is 64974563109  speedup is 64027.28
I, [15.10.09 11:46:17#7343]  INFO -- : Still 3 tasks backing up user1@host2, user1@host4, user2@host1
I, [15.10.09 11:47:17#7343]  INFO -- : Still 3 tasks backing up user1@host2, user1@host4, user2@host1

Run in crontab

Finally I added a new entry of the root user crontab with “crontab -e” which will start the script every hour.

0 * * * * /usr/bin/ruby /root/backup.rb

Setting up my Solaris fileserver (Part 2)

To enable mirroring on my two HDDs I tried to follow the steps described at and but got a little confused by the different device names.

What I needed to do is copy the partition table from the first drive to the second one and then I could attach it to the rpool. The following steps I did as a root user.

# zpool status

 pool: rpool
 state: ONLINE
 scrub: none requested

 rpool       ONLINE       0     0     0
   c8d0s0    ONLINE       0     0     0

errors: No known data errors

Meaning: my first disk is c8d0s0 and it is attached directly to the rpool.

# format

Searching for disks...done

 0. c8d0 <DEFAULT cyl 19454 alt 2 hd 255 sec 63>
 1. c8d1 <DEFAULT cyl 19454 alt 2 hd 255 sec 63>

So my second drives name is c8d1. I chose option (1) and used the fdisk command to create a solaris2 partition. Then I quit the format command.

To copy the partition table from the first drive to the second one I used:

# prtvtoc /dev/rdsk/c8d0s2|fmthard -s - /dev/rdsk/c8d1s2

Then I could force attach the second drive to the rpool:

# zpool attach rpool c8d0s0 c8d1s0
invalid vdev specification
use '-f' to override the following errors:
/dev/dsk/c8d1s0 overlaps with /dev/dsk/c8d1s2

# zpool attach -f rpool c8d0s0 c8d1s0
Please be sure to invoke installgrub(1M) to make 'c8d1s0' bootable.

# zpool status
 pool: rpool
 state: ONLINE
 scrub: resilver completed after 0h2m with 0 errors on Mon Jul 13 10:16:55 2009

 rpool       ONLINE       0     0     0
   mirror    ONLINE       0     0     0
     c8d0s0  ONLINE       0     0     0
     c8d1s0  ONLINE       0     0     0  4,18G resilvered

errors: No known data errors

To make the second drive also bootable I invoked installgrub

# installgrub /boot/grub/stage1 /boot/grub/stage2 /dev/rdsk/c8d1s0
stage1 written to partition 0 sector 0 (abs 16065)
stage2 written to partition 0, 271 sectors starting at 50 (abs 16115)

The next task will be to install the four different 1 TB HDDs I also bought into that Chenbro case and create a zpool for them.

Setting up my Solaris fileserver (Part 1)

Finally I had the time (and money 🙂 to fullfil my long lasting wish to setup my own fileserver running Solaris and ZFS. Since I wanted to use it also as a potential test server for my projects I decided to use a slightly bigger processor. I ordered a BTO system at with the following configuration:

  • Fan: Arctic Alpine  64 PRO
  • CPU: AMD X2CV  GE4450E AM2 2300    2000 1MB
  • Power supply: Corsair CMPSU-400CX   400W ATX2
  • Case: A+case  Seenium         Black
  • Mainboard: GiBy GA-M85M-US2H GF8100 RGVSM
  • 1st boot HDD: Samsung  160 GB SAT2 HD161GJ
  • 2nd boot HDD: Maxtor   160 GB SATA STM3160813AS
  • RAM: D2 2GB  800-5     128×8     tMS
  • DVD: Lite DH-16D3P        16x AT        Bl  B

The first installation of OpenSolaris 2009.06 went quite smoothly but then I had to discover that I am back in tinker land: the onboard network interface was not recognized. After many hours of reinstalling, searching the web and so on (I know why I use a Mac 😉 I found this use page of a guy who had the same problems:

“scanpci -v” returned this in my case:

pci bus 0x0000 cardnum 0x0a function 0x00: vendor 0x10de device 0x0760
 nVidia Corporation MCP78S [GeForce 8200] Ethernet
 CardVendor 0x1458 card 0xe000 (Giga-byte Technology, Card unknown)
 STATUS    0x00b0  COMMAND 0x0007
 CLASS     0x02 0x00 0x00  REVISION 0xa2
 BIST      0x00  HEADER 0x00  LATENCY 0x00  CACHE 0x00
 BASE0     0xfc008000 SIZE 4096  MEM
 BASE1     0x0000dc00 SIZE 8  I/O
 BASE2     0xfc009000 SIZE 256  MEM
 BASE3     0xfc00a000 SIZE 16  MEM
 BASEROM   0x00000000  addr 0x00000000
 MAX_LAT   0x14  MIN_GNT 0x01  INT_PIN 0x01  INT_LINE 0x0f

Since I have a different mainboard with a Geforce 8200 chip I tried to use the latest drivers. After two reinstalls I got it up and running with these steps running as a root user:

gunzip nfo-2.6.3.tar.gz
tar -xvf nfo-2.6.3.tar
cd nfo-2.6.3
rm obj Makefile
ln -s Makefile.${KARCH}_${COMPILER} Makefile  ( for me it was ln -s Makefile.amd64_gcc  Makefile )
ln -s ${KARCH} obj ( for me it was ln -s amd64 obj )
rm Makefile.config
ln -s Makefile.config_gld3 Makefile.config
/usr/ccs/bin/make install
cp nfo.conf /kernel/drv/nfo.conf

After these steps a reboot did the trick.

Build your own Drobo-Replacement based on ZFS

The Drobo hype

I saw the first Drobo presentation video on YouTube almost 2 years ago. Since then I was longing to get one, but the price for an empty box being 490,- € without a single harddrive was too much in my oppinion.

As a regular podcast listener I heared everywhere about the sexyness of the Drobo: MacBreak Weekly mentions it in every episode, the guys at BitsUndSo are collecting them like crazy, and finally Tim Pritlove also got one. But then he mentioned on his podcast Mobile Macs his strange difficulties with the Drobo which made me think a little bit more about the subject.

The Drobo has in my opinion some major drawbacks:

  • it doesn’t know its hosted data and the used filesystem, so on a resilvering task it has to duplicate all parts of a harddrive, also the ones with noise
  • one has to set an upper limit for the hosted filesystem, so Drobo acts to the host machine as one physical drive with a given size
  • you cannot use all the disk space if you use drives with different sizes
  • it is limited to a maximum amount of 4 drives
  • if your Drobo fails you cannot access your data

We can do better!

So what would I want from my dream backup device?

  • it should not have an upper storage limit
  • it should be able to heal itself silently
  • it should be network accessible (especially for Macs)
  • the drives should also work when connected to other hardware
  • it should be usable as a Time Machine target
  • it HAS to be cheaper than a Drobo

It doesn’t have to be beautiful or silent, since I want to put it in my storage room and want to forget about it.

Initial thoughts

In my oppinion the most modern and future proof filesystem at the moment is ZFS. After listening to the very good podcast episode of Chaos Radio Express CRE049 in German about ZFS by Tim Pritlove I always wanted to use it. Unfortunately Apple is very lazy with its ZFS plans. It is included in Leopard but can only read ZFS and the plans for Snow Leopard are very vague. So Mac OS X is no option at the moment. Since I want it to be cheap, Mac hardware is also no option.

FreeBSD seems to have a recent version of ZFS, but I gave OpenSolaris a try, since ZFS is developed by Sun I think Solaris is the first OS where new features of ZFS will appear. Bleading edge is always best 😉 so I looked further into this setting.

Test driving OpenSolaris

I wanted to make some more investigations so before using real hardware I wanted to test drive it with a virtualization software. After downloading the current ISO version of OpenSolaris 2008.11 I tried to install it on my Mac with VMWare Fusion but at that time I didn’t know that Solaris and OpenSolaris are the same so I had difficulties setting up the VM properly.

So I tried out VirtualBox and hoped, since it is now owned by Sun, it will work like a charm virtualizing Solaris. I set up a new VM with one boot disk and four raid disks.


I switched on all the fancy CPU extensions. There is only one ISO image for both x86/x64 so I turned on x64 and it automatically used the 64-Bit kernel. The hardware recommencations for ZFS say, that it works best with 64 Bit and at least 1 GB of RAM.

Installing OpenSolaris from the Live system worked very well. I was very surprised by the polished look thanks to Gnome (although I am a KDE fanboy). ZFS is now used by default as the boot filesystem on Solaris so I had to do nothing to activate it.

When the installation was complete and the system was up and running I made a little tweak to get access via SSH to the VM. Since it used NAT I set up a port forward from 2222 to 22 on my Mac. I edited the XML file of my virtual machine (~/Library/VirtualBox/Machines/Open Solaris/Open Solaris.xml in my case) and inserted the following lines to the DataItem section:

      <ExtraDataItem name="VBoxInternal/Devices/e1000/0/LUN#0/Config/ssh/HostPort" value="2222"/>
      <ExtraDataItem name="VBoxInternal/Devices/e1000/0/LUN#0/Config/ssh/GuestPort" value="22"/>
      <ExtraDataItem name="VBoxInternal/Devices/e1000/0/LUN#0/Config/ssh/Protocol" value="TCP"/>

After starting the VM I could connect with “ssh -l <user> -p 2222 localhost” to it.

I used to work for several years with a Linux system and after that on Mac OS X. I had no problems adapting to the Solaris world, since they took many products from the open source world like bash and integrated it. So the learing curve using this system seems very flat.

To get some info about the system I entered the following commands:

Get info about the kernel mode

$ isainfo -kv
64-bit amd64 kernel modules

Listing all system devices

$ prtconf -pv
System Configuration:  Sun Microsystems  i86pc
Memory size: 1061 Megabytes
System Peripherals (PROM Nodes):

Node 0x000001
    bios-boot-device:  '80'

Show the system log

$ cat /var/adm/messages

Setting up the storage pool

Since I want to have one huge storage pool which can grow over the time I used RAIDZ.

The following commands where entered as root.

First to get all connected storage devices:

# format
Searching for disks...done

       0. c3d0 <DEFAULT cyl 2044 alt 2 hd 128 sec 32>
       1. c5t0d0 <ATA-VBOX HARDDISK-1.0-8.00GB>
       2. c5t1d0 <ATA-VBOX HARDDISK-1.0-8.00GB>
       3. c5t2d0 <ATA-VBOX HARDDISK-1.0-8.00GB>
       4. c5t3d0 <ATA-VBOX HARDDISK-1.0-8.00GB>
Specify disk (enter its number): ^C

The green ids are the device ids we need to set up the storage pool. To create a pool named “tank” I entered:

zpool create -f tank raidz c5t0d0 c5t1d0 c5t2d0 c5t3d0

To show the available pools type:

# zpool list
rpool  3,97G  2,90G  1,07G    73%  ONLINE  -
tank   31,8G   379K  31,7G     0%  ONLINE  -

rpool is the pool on the boot device. You can see, that the space you get connecting 4 drives with 8 GB is almost 32 GB. When you store something on that pool it is stored redundantly and uses about 30 % more space to ensure the safety when one device is failing.

Now I created a filesystem on that pool

# zfs create tank/home

It is linked automatically to /tank/home. To get all live zfs filesystems enter

# zfs list
rpool                   3,44G   482M    72K  /rpool
rpool/ROOT              2,71G   482M    18K  legacy
rpool/ROOT/opensolaris  2,71G   482M  2,56G  /
rpool/export             746M   482M    21K  /export
rpool/export/home        746M   482M    19K  /export/home
rpool/export/home/mk     746M   482M  45,4M  /export/home/mk
tank                     682M  22,7G  26,9K  /tank
tank/home                681M  22,7G  29,9K  /tank/home

In this example I copied the OpenSolaris ISO image to my new filesystem. It occupies 681M. On the pool it occupies 911M.

#zpool list
rpool  3,97G  3,44G   545M    86%  ONLINE  -
tank   31,8G   911M  30,9G     2%  ONLINE  -

A very nice feature of ZFS is built-in compression. Properties of file systems are inherited so if you set compression on tank/home and create a new system inside of it it is compressed automatically:

# zfs set compression=on tank/home
# zfs get compression tank/home
tank/home  compression  on         local
# zfs create tank/home/mk
# zfs get compression tank/home/mk
NAME          PROPERTY     VALUE         SOURCE
tank/home/mk  compression  on            inherited from tank/home

Health insurance

ZFS data validity is ensured by internal checksums so it can see on the fly if data is still valid and can reconstruct if necessary.

To get the status of a pool enter

# zpool status -v tank
  pool: tank
 state: ONLINE
 scrub: none requested

        NAME        STATE     READ WRITE CKSUM
        tank        ONLINE       0     0     0
          raidz1    ONLINE       0     0     0
            c5t0d0  ONLINE       0     0     0
            c5t1d0  ONLINE       0     0     0
            c5t2d0  ONLINE       0     0     0
            c5t3d0  ONLINE       0     0     0

errors: No known data errors

A scrub is a filesystem check which should be done with consumer quality drives on a weekly basis and can be trigged by

# zpool scrub tank

and after some time check the result with

# zpool status -v tank
  pool: tank
 state: ONLINE
 scrub: scrub completed after 0h2m with 0 errors on Tue Jan 13 11:36:38 2009

        NAME        STATE     READ WRITE CKSUM
        tank        ONLINE       0     0     0
          raidz1    ONLINE       0     0     0
            c5t0d0  ONLINE       0     0     0
            c5t1d0  ONLINE       0     0     0
            c5t2d0  ONLINE       0     0     0
            c5t3d0  ONLINE       0     0     0

errors: No known data errors

Gnome Time Machine

When logging into a Gnome session and browsing through the menues I noticed the program “Time Slider Setup”.


When you activate it, it will create ZFS snapshots on a regular basis. These snapshots don’t waste disk space and you can travel back in time (not as fancy as with Time Machine, but who cares) with the Gnome file browser Nautilus.


That is a killer feature and if I still would be a Linux/Java developer, this would be a good reason for me to switch to OpenSolaris. You don’t have to use a RAID with ZFS to make snapshots, so your filesystem has a built-in time-based versioning system. *cool*

Network accessiblity

My next step was to set up Netatalk on Solaris using this guide. I first had some difficulties and had to install gmake and gcc. The described patches didn’t work correctly since the file /usr/ucbinclude/sys/file.h was missing, so I changed the #ifdef statement from

#if defined( sun ) && defined( __svr4__ )
#include </usr/ucbinclude/sys/file.h>
#else /* sun __svr4__ */


#if defined( sun ) && !defined( __svr4__ )
#include </usr/ucbinclude/sys/file.h>
#else /* sun __svr4__ */

in all source files where it occurred:

  • etc/atalkd/main.c
  • etc/cnid_dbd/dbif.c
  • etc/papd/main.c
  • etc/papd/lp.c
  • sys/solaris/tpi.c

I need further work with this to get it running with Time Machine.

Getting real

So everything looks promising at first glance. The next logical step would be to buy  the hardware components and try everything out. I configured bare systems with midi towers using AMD or Intel processors for approximately 170,- to 190,- €. Thats about half the price of a Drobo. For each SATA hard drive I would buy a hot pluggable case. Another option would be to use external USB drives but that might lead to a quiet cluttered and fragile construction.

I need to investigate further to use the correct components. Motherboards tested with OpenSolaris are listed here:

ZFS has a hotplug feature so if a device fails it can be replaced without rebooting and typing in any commands. But if that fails one can also enter some commands into the commandline.

Next steps

I really need to invest more time with the VM and try to corrupt some disk images and how ZFS reacts to that. Also expanding existing pools with different sizes will be interesting.

Of course I need to get Netatalk working and try to use it as a Time Machine target. I could use the VM on a different host to simulate to final system.

Stay tuned for my future investigations and please don’t start trolling about the superiority of the Drobo. I think that is a matter of taste.