Discovering Omnios Server


Doing some tidying in my network, computers and VPS collection, I went looking for a piece of software that could be used :

After looking at SmartOS , I tried OmniOS . It is also based on Illumos . The notes go here.


Read about a fresh installation and getting started with OmniOS .

Download and transfer it to a USB Flash Drive:

# dd if=omnios-r151048.iso of=/dev/rsd2c bs=1M

Booting the ISO using Ventoy did not work. Well, it worked but the installer stopped saying it wouldn’t find its data.

Insert the flash drive and power on the machine.


OmniOS comes with a nice friendly ncurse-like text installer. You can also use “the old text” installer which is more 1 question / 1 line ; a bit like OpenBSD installer.

As the machine was previously running SmartOS, the disks were configured for ZFS. To prevent issues, I used the installer option to start from scratch. On the “Welcome to the OmniOSce installer”, select the Configure Boot Options and toggle the Reconfigure variable.

My installation went:

Wait for installation to proceed. When installation is complete, select Configure the installed OmniOS system.

Return to main menu and Reboot.

Remove the USB stick when screen gets blank.

The first boot is quite long. “Applying initial boot settings” seem to take quite a few moments.

By default, the root user cannot log in using SSH. Don’t forget to create an Admin account during install. Connect using SSH and start admining.

Secured SSH connections

Install the SSH keys, force the key usage and restart the daemon:

$ mkdir ~/.ssh
$ cat > ~/.ssh/authorized_keys
ssh-ed25519 (...)

$ su -
# cat >> ~/.ssh/authorized_keys
ssh-ed25519 (...)

# vi /etc/ssh/sshd_config
PermitRootLogin prohibit-password
PasswordAuthentication no

# svcs | grep ssh
online         20:09:39 svc:/network/ssh:default
# svcadm restart ssh

Enable IPv6

To use IPv6 auto-configuration, simply:

# ipadm create-addr -T addrconf igb0/v6

Package management and Upgrading

Quick cheatsheet for package management:

ZFS pools and datasets

I want the OS on the mSATA and the data on the SSD, so let’s create the new pool.

# diskinfo
TYPE  DISK    VID      PID              SIZE         RMV SSD
SATA  c2t0d0  ATA      BT58SSD10M        238.47 GiB  no  yes
SATA  c2t1d0  Samsung  SSD 870 QVO 8TB  7452.04 GiB  no  yes

# zpool create -f tank c2t1d0

# zpool list
rpool   238G  4.87G   233G        -         -    0%   2%  1.00x  ONLINE  -
tank   7.27T   102K  7.27T        -         -    0%   0%  1.00x  ONLINE  -

According to the manual, I’d rather go for the LZ4 compression algorythm.

The lz4 compression algorithm is a high-performance replacement for the lzjb algorithm. It features significantly faster compression and decompression, as well as a moderately higher compression ratio than lzjb, but can only be used on pools with the lz4_compress feature set to enabled. See zpool-features(7) for details on ZFS feature flags and the lz4_compress feature.

Activate LZ4 compression on the data pool.

# zpool get feature@lz4_compress
NAME   PROPERTY              VALUE                 SOURCE
rpool  feature@lz4_compress  active                local
tank   feature@lz4_compress  active                local

# zfs set compression=lz4 tank

# zfs get compression
NAME                                            PROPERTY     VALUE     SOURCE
rpool                                           compression  on        local
rpool/ROOT                                      compression  on        inherited from rpool
rpool/ROOT/omnios-r151048                       compression  on        inherited from rpool
rpool/ROOT/omnios-r151048b                      compression  on        inherited from rpool
tank                                            compression  lz4       local

Create some ZFS dataset and enable deduplication. We’ll see later on if this is useful.

# for d in backup nocloud zones; do      \
  zfs create -o mountpoint=/$d tank/$d ; \
  zfs set dedup=edonr,verify tank/$d ;   \

# zfs get dedup,compression
NAME                                            PROPERTY     VALUE          SOURCE
rpool                                           dedup        off            default
rpool                                           compression  on             local
rpool/ROOT                                      dedup        off            default
rpool/ROOT                                      compression  on             inherited from rpool
tank                                            dedup        off            default
tank                                            compression  lz4            local
tank/backup                                     dedup        edonr,verify   local
tank/backup                                     compression  lz4            inherited from tank
tank/nocloud                                    dedup        edonr,verify   local
tank/nocloud                                    compression  lz4            inherited from tank
tank/zones                                      dedup        edonr,verify   local
tank/zones                                      compression  lz4            inherited from tank

Zone Management Tool

zadm is a third-party tool that allows user-friendly Zones management. Let’s install it:

# pkg install zadm

Asciinerama casts are available here . They demonstrate basic Zones tasks.


IPF can be used to filter access to the Global Zone services.

# svcadm enable network/ipfilter

# vim /etc/ipf/ipf.conf
pass  in quick on lo0 all
pass out quick on lo0 all
block in all
pass  in quick on igb0 proto icmp keep state
pass  in quick on igb0 proto tcp to port = 22 keep state
pass out all

# ipf -Fa -f /etc/ipf/ipf.conf -nv
# ipf -Fa -f /etc/ipf/ipf.conf

# ipfstat -io

To be continued

From here, there’s a couple of use-cases I want to implement. I am testing a few with success so far. I think OmniOS should become my second prefered system.

I’ll probably write about use-cases later on.


Here is a list of articles I found very usefull while exploring OmniOS. I recommend reading them.