2015-01-07: I’ve updated this post to to reflect changes in FreeNAS 9.3.

I’ve been using OpenIndiana since late 2011 and switched to OmniOS in 2013. Lately I started testing FreeNAS, what drove me to do this is I use CrashPlan to backup my pool but recently Code 42 announced they’ll be discontinuing Solaris support for Crashplan so I needed to look for an alternative OS or an alternative backup solution. I looked at FreeNAS because it has a CrashPlan plugin that runs in a jail using Linux emulation. After testing it out for a while I will likely stay on OmniOS since it suits my needs better and instead switch out CrashPlan for ZnapZend for my backup solution. But after running FreeNAS for a few months here are my thoughts on both platforms and their strengths and weaknesses as a ZFS storage server.

Update: 2015-01-07: After a lot of testing ZnapZend ended up not working for me, this is not it’s fault, but because I have limited and bandwidth, the snapshots don’t catch up and it gets further and further behind so for now I’m continuing with Crashplan on OmniOS. I am also testing FreeNAS and may consider a switch at some point.

CIFS / SMB Performance for Windows Shares

FreeNAS has a newer implementation of SMB, supporting SMB3, I think OmniOS is at SMB1. FreeNAS can function as an Active Directory Domain Controller.

OmniOS is slightly faster, writing a large file over my LAN gets around 115MBps vs 98MBps on FreeNAS. I suspect this is because OmniOS runs NFS SMB at the kernel level and FreeNAS runs it in user space. I tried changing the FreeNAS protocol to SMB2, and even SMB1 but couldn’t get past 99MBps. This is on a Xeon E3-1240V3 so there’s plenty of CPU power, Samba on FreeNAS just can’t keep up.

CIFS / SMB Snapshot Integration with Previous Versions

Previous Versions Snapshot Integration with Windows is far superior in OmniOS. I always use multiple snapshot jobs to do progressive thinning of snapshots. So for example I’ll setup monthly snaps with a 6 month retention, weekly with two-month retention, daily with two week, hourly with 1 week, and every 5 minutes for two days. FreeNAS will let you setup the snap jobs this way, but in Windows Previous Versions it will only show the snapshots from one of the snap jobs under Previous Versions (so you may see your every 5 minute snaps but you can’t see the hourly or weekly snaps). OmniOS handles this nicely. As a bonus Napp-It has an option to automatically delete empty snapshots sooner than their retention expiration, so I don’t see them in Previous Versions unless some data changed.

Enclosure Management

Both platforms struggle here, FreeNAS has a bit of an edge here… probably the best thing to do is record the serial number of each drive with the slot number. In FreeNAS drives are given device names like da0, da1, etc. but unfortunately the numbers don’t seem to correspond to anything and they can even change between reboots. FreeNAS has the ability to label drives so you could insert one drive at a time and label them with the slot they’re in.

OmniOS drives are given names like c3t5000C5005328D67Bd0 which isn’t entirely helpful.

For LSI controllers, the sas2irc utility (which works on FreeBSD or Solaris) will map the drives to slots.

Fault Management

The ZFS fault management daemon will automatically replace a failed drive with a hot spare… but it hasn’t been ported to FreeBSD yet, so FreeNAS only has warm spare capability. Update: FreeNAS added hot spare capability on Feb 27, 2015. To me this is a minor concern… if you will use RAID-Z with a hot spare why not just configure the pool with RAID-Z2 or RAID-Z3 to begin with? However, I can see how the fault management daemon on OmniOS would reduce the amount of work if you had several hundred drives and failures were routine.

SWAP issue on FreeNAS

While I was testing, I had a drive fail (this is why 3-year old Seagate drives are great to test with) and FreeNAS crashed! The NFS pool dropped out from under VMware. When I looked at the console I saw “swap_pager: I/O error – pagein failed” I had run into FreeNAS Bug 208 (removed dead link) which was closed a year ago but never resolved. The default setting in FreeNAS is to create a 2GB swap partition on every drive which acts like striped swap space (I am not making this up, this is the default setting). So if any one drive fails, it can take FreeNAS down. The argument from FreeNAS is that you shouldn’t be using swap—and perhaps that’s true but I had a FreeNAS box with 8GB memory and running only one jail with CrashPlan bring my entire system down because a single drive failed. That’s not an acceptable default setting. Fortunately, there is a way to disable automatically creating swap partitions on FreeNAS, it’s best to disable the setting before initializing any disks.

In my three years of running an OpenSolaris / Illumos based OS I’ve never had a drive failure bring the system down

Running under VMware

FreeNAS is not supported running under a VM (this is now a supported configuration) but OmniOS is. In my testing both OmniOS and FreeNAS work well under VMware under the best practices of passing an LSI controller flashed into IT mode to the VM using VT-d. I found that OmniOS does a lot better virtualized on slower hardware than FreeNAS. On an Avaton C2750 FreeNAS performed well on bare metal, but when I virtualized it using vmdks on drives instead of VT-d FreeNAS suffered in performance but OmniOS performed well under the same scenario.

Both platforms have VMXNET3 drivers, neither has a Paravirtual SCSI driver.

Encryption

Unfortunately, Oracle did not release the source for Solaris 11, so there is no encryption support on OpenZFS directly.

FreeNAS can take advantage of FreeBSD’s GELI based encryption. FreeBSD’s implementation can use the AES instruction set, last I tested Solaris 11 the AES instruction set was not used so FreeBSD/FreeNAS probably has the fastest encryption implementation for ZFS.

There isn’t a good encryption option on OmniOS.

ZFS High Availability

Neither systems supports ZFS high availability out of the box. OmniOS can use a third-party tool like RSF-1 (paid) to accomplish this. The commercially supported TrueNAS uses RSF-1 so it should also work in FreeNAS.

ZFS Replication & Backups

FreeNAS can easily setup replication as often as every 5 minutes which is a great way to have a standby host to failover to. Replication can be done over the network. If you will replicate over the internet, I’d say you want a small data set or a fast connection—I ran into issues a couple of times where the replication got interrupted and it needed to start all over from scratch. On OmniOS Napp-It does not offer a free replication solution, but there is a paid replication feature, however there are also numerous free ZFS replication scripts that people have written such as ZnapZend.

I did get the CrashPlan plugin to work under FreeNAS, however I found that after a reboot the CrashPlan jail sometimes wouldn’t auto-mount my main pool so it ended up not being a reliable enough solution for me to be comfortable with. I wish FreeNAS made it so it wasn’t in a jail.

Memory Requirements

FreeNAS is a little more power hungry than OmniOS. For my 8TB pool a bare minimum for FreeNAS is 8GB while OmniOS is happy with 4GB, although I run it with 6GB to give it a little more ARC.

Hardware Support

FreeNAS supports more hardware than OmniOS. I virtualize my ZFS server so it doesn’t matter too much to me but if you’re running bare metal and on obscure or newer hardware, there’s a much better chance that FreeNAS supports it. Also in 9.3 you can configure IPMI from the web interface.

VAAI (VMware vSphere Storage API’s — Array Integration)

FreeNAS now has VAAI support for iSCSI. OmniOS has no VAAI support. As of FreeNAS 9.3 and Napp-It 0.9f4 both control panels can enable VMware snapshot integration / ESXi hot snaps. The way this works is before every ZFS snapshot is taken FreeNAS has VMware snap all the VMs, then the ZFS snapshot is taken, then the VMware snapshots are released. This is nice and allows for proper consistent snapshots.

GUI

The FreeNAS GUI looks a little nicer and is probably a little easier for a beginner. The background of the screen turns red whenever you’re about to do something dangerous. I found you can set up just about everything from the GUI, where I had to drop into the command line more often with OmniOS. The FreeNAS web interface seems to hang for a few seconds from time to time compared to Napp-It, but nothing major. I believe FreeNAS will have an asynchronous GUI in version 10.

One frustration I have with FreeNAS is it doesn’t quite do things compatible with CLI. For example, if you create a pool via CLI FreeNAS doesn’t see it, you have to import it using the GUI to use it there. Napp-it is essentially an interface that runs CLI commands so you can seamlessly switch back and forth between managing things on CLI and Napp-It. This is a difference in philosophy. Napp-It is just a web interface meant to run on top of an OS, where FreeNAS is more than just a web app on top of FreeBSD, FreeNAS is its own OS.

I think most people experienced with the ZFS command line and Solaris will be a little more at home with Napp-It’s control panel, but it’s easy enough to figure out what FreeNAS is doing. You just have to be careful what you do in the CLI.

On both platforms I found I had to switch into CLI from time to time to do things right (e.g. FreeNAS can’t set sync=always from the GUI, Napp-It can’t setup networking).

As far as managing a ZFS file system both have what I want.. email alerts when there’s a problem, scheduling for data scrubs, snapshots, etc.

FreeNAS has better security, it’s much easier to set up an SSL cert on the management interface, in fact you can create an internal CA to sign certificates from the GUI. Security updates are easier to manage from the web interface in FreeNAS as well.

Community

FreeNAS and OmniOS both have great communities. If you post anything at HardForum chances are, you’ll get a response from Gea and he’s helpful. There is a lot of info on the FreeNAS forums and the FreeNAS Jira project is open so you can see all the issues, it’s a great way to see what bugs and feature requests are out there and when they were or will be fixed. OmniOS has an active OmniOS Discuss mailman list and Gea, the author of Napp-It is active on various forums. He has answered my questions frequently over at HardForum’s Data Storage subforum. I’ve found the HardForum community a little more helpful…I’ve always gotten a response there while several questions I posted on the FreeNAS forums went unanswered.

Documentation

FreeNAS documentation is great, like FreeBSD’s. Just about everything is in the FreeNAS Guide

OmniOS isn’t as organized. I found some howtos here, not nearly as comprehensive as FreeNAS. Most of what I find from OmniOS I find in forums or the Napp-It site.

Mirrored ZFS boot device / rpool

OmniOS can boot to a mirrored ZFS rpool.

FreeNAS does not have a way to mirror the ZFS boot device. FreeBSD does have this capability but it turns out FreeNAS is built on NanoBSD. The only way to get FreeNAS to have redundancy on the boot device that I know of is to set it up on a hardware RAID card.

FreeNAS 9.3 can now install to a mirrored ZFS rpool!

Features / Plugins / Extensions

Napp-It’s extensions include:

AMP (Apache, MySQL, PHP stack)

Baikal CalDAV / CardDAV Server

Logitech MediaServer

MediaTomb (DLNA / UPnP server)

Owncloud (Dropbox alternative)

PHPvirtualbox (VirtualBox interface)

Pydio Sharing

FTP Server

Serviio Mediaserver

Tine Groupware

FreeNAS plugins:

Bacula (Backup Server)

BTSync (Bittorrent Sync)

CouchPotato (NZB and Torrent downloader)

CrashPlan (Backup client/server)

Cruciblewds (Computer imaging / cloning)

Firefly (media server for Roku SoundBridge and Apple iTunes)

Headphones (automatic music downloader for SABnzbd)

HTPC-Manager

LazyLibrarian (follow authors and grab metadata for digital reading)

Maraschino (web interfrace for XBMC HTPC)

MineOS (Minecraft control panel)

Mylar (Comic book downloader)

OwnCloud (Dropbox alternative)

PlexMediaServer

s3cmd

SABnzbd (Binary newsreader)

SickBeard (PVR for newsgroup users)

SickRage (Video file manager for TV shows)

Subsonic (music streaming server)

Syncthing (Open source cluster synchronization)

Transmission (BitTorrent client)

XDM (eXtendable Download Manager)

All FreeNAS plugins run in a jail so you must mount the storage that service will need inside the jail… this can be annoying but it allows for some nice security—for example CrashPlan can mount the storage you want to back up as read-only.

Protocols and Services

Both systems offer a standard stack of AFP, SMB/CIFS, iSCSI, FTP, NFS, RSYNC, TFTP

FreeNAS also has WebDAV and few extra services like Dynamic DNS, LLDP, and UPS (the ability to connect to a UPS unit and shutdown automatically).

Performance Reporting and Monitoring

Napp-It does not have reports and graphs in the free version. FreeNAS has reports and you can look back as far as you want to see historical performance metrics.

As a Hypervisor

Both systems are very efficient, running guests of the same OS. OmniOS has Zones, FreeNAS can run FreeBSD Jails. OmniOS also has KVM which can run any OS. I suspect that FreeNAS 10 will have Bhyve. Also both can run VirtualBox.

Stability vs Latest

Both systems are stable, OmniOS/Napp-It seems to be the most robust of the two. The OmniOS LTS updates are very minimal, mostly security updates and a few bug fixes. Infrequent and minimal updates are what I like to see in a storage solution.

FreeNAS is pushing a little close to the cutting edge. They have frequent updates pushed out—sometimes I think they are too frequent to have been thoroughly tested. On the other hand, if you come across an issue or feature request in FreeNAS and report it chances are they’ll get it in the next release pretty quickly.

Because of this, OmniOS is behind FreeNAS on some things like NFS and SMB protocol versions, VAAI support for iSCSI, etc.

I think this is an important consideration. With FreeNAS you’ll get newer features and later technologies while OmniOS LTS is the better platform for stability. The commercial TrueNAS solution is also going to robust. For FreeNAS you could always pick a stable version and not update often—I really wish FreeNAS had an LTS, or at least a slower moving stable branch that maybe only did quarterly updates except for security fixes.

ZFS Integration

OmniOS has a slight edge on ZFS integration. As I mentioned earlier OmniOS has multi-tiered snapshot integration into the Windows Previous versions feature where FreeNAS can only pick one snap-frequency to show up there. Also, in OmniOS NFS and SMB shares are stored as properties on the datasets so you can export the pool, import it somewhere else and the shares stay with the pool so you don’t have to reconfigure them.

Commercial Support

OmniOS offers Commercial Support if you want it.

iX Systems offers supported TrueNAS appliances.

Performance

On an All-in-one setup, I setup VMware ESXi 6.0, a virtual storage network and tested FreeNAS and OmniOS using iSCSI and NFS. On all tests MTU is set to 9000 on the storage network, and compression is set to LZ4. iSCSI volumes are sparse ZVOLs. I gave the ZFS server 2 cores and 8GB memory, and the guest VM 2 cores and 8GB memory. The guest VM is Windows 10 running Crystal Benchmark.

Environment:

Supermicro X10SL7-F with LSI 2308 HBA flashed to IT firmware and passed to ZFS server via VT-d (I flashed the P19 firmware for OmniOS and then re-flashed to P16 for FreeNAS).

Intel Xeon E3-1240v3 3.40Ghz.

16GB ECC Memory.

6 x 2TB Seagate 7200 drives in RAID-Z2

2 x 100GB DC S3700s striped for ZIL/SLOG. Over-provisioned to 8GB.

Latest stable updates on both operating systems:

FreeNAS 9.3 update 201503200528

OmniOS r151012 omnios-10b9c79

On Crystal Benchmark I ran 5 each of the 4000MB, 1000MB, and 50MB size tests, the results are the average of the results.

On all tests every write was going to the ZIL / SLOG devices. On NFS I left the default sync=standard (which results in every write being a sync with ESXi). On iSCSI I set sync=always, ESXi doesn’t honor sync requests from the guest with iSCSI so it’s not safe to run with sync=standard.

Update: 7/30/2015: FreeNAS has pushed out some updates that appear to improve NFS performance. See the newer results here: VMware vs bhyve Performance Comparison. Original results below.

Sequential Read MBps

OmniOS is faster at NFS while FreeNAS pulls ahead on iSCSI.

Sequential Write MBps

OmniOS is significantly faster with NFS sequential writes. No significant difference with iSCSI

Random Read 512K MBps

No significant difference on NFS, FreeNAS is faster on random iSCSi reads.

Random Write 512K MBps

OmniOS is faster at random NFS writes. No significant difference for iSCSI.

Random Read 4K IOPS

OmniOS is faster at NFS and iSCSI random reads.

Random Write 4K IOPS

OmniOS is faster wit NFS random writes, no significant difference for iSCSI.

Random Read 4K QD=32 IOPS

No significant difference except when using large blocks on NFS, then FreeNAS slows down.

Random Write 4K QD=32 IOPS

OmniOS tends to do a little better.

Performance Thoughts

So it appears, from these unscientific benchmarks that OmniOS on NFS is the fastest configuration, iSCSI performs pretty similarly on both FreeNAS and OmniOS depending on the test. One other thing I should mention, which doesn’t show up in the tests, is latency. With NFS I saw latency on the ESXi storage as high as 14ms during the tests, while latency never broke a millisecond with iSCSI.

One major drawback to my benchmarks is its only one guest hitting the storage. It would interest to repeat the test with several VMs accessing the storage simultaneously, I expect the results may be different under heavy concurrent load.

I chose 64k iSCSI block size because the larger blocks result in a higher LZ4 compression ratio; I did several quick benchmarks and found 16K and 64K performed pretty similarly, 16K performed better at random 4K write QD=1, but otherwise 64K was close to a 16K block size depending on the test. I saw a significant drop in random performance at 128k. Once again under different scenarios this may not be the optimal block-size for all types of workloads.