OpenMediaVault – A few notes

Following on from my brief look at FreeNAS here, I thought I’d do a quick article on OpenMediaVault as well. While it isn’t quite as mature as FreeNAS, it is based on Debian. I’ve had a soft spot for Debian ever since I was able to get it running on a DECpc AXP 150 I had lying about many moons ago. The Jensen is no longer with us, but the fond memories remain. Anyway …

Firstly, you can download OpenMediaVault here. It’s recommended that you install it on a hard drive (ideally in a RAID 1 configuration) rather than on USB or SD cards. Theoretically you could put it on a stick and redirect the more frequently written stuff to a RAM disk if you really didn’t want to give up the SATA ports on your board. I decided to use an SSD I had laying about as I couldn’t be bothered with more workarounds and “tweaks”. You can follow this guide to setup some semi-automated backup of the configuration.

Secondly, here’s a list of the hardware I used for this build:

  • Mainboard – ASRock N3700-ITX
  • CPU – Intel Quad-Core Pentium Processor N3700 (on-board)
  • RAM – 2 * Kingston 8GB 1600MHz DDR3 Non-ECC CL11 SODIMM
  • HDDs – 1 * SSD, 8 * Seagate Constellation ES 2TB drives
  • SATA Controller PCIe x1 4-port SATA III controller (non-RAID), using a Marvell 88SE9215 chipset
  • IO Crest Mini PCIe 2-port SATA III controller (RAID capable), using a Syba (?) chipset
  • Case – Fractal Design Node 804
  • PSU – Silverstone Strider Essential 400W


You’ll notice the lack of ECC RAM, and the board is limited in SATA ports, hence the requirement for a single-lane, 4-port SATA card. I’m really not the best at choosing the right hardware for the job. The case is nice and roomy, but there’s no hot-swap for the disks. A better choice would have been a workstation-class board with support for ECC RAM, a decent CPU and a bunch of SATA ports in a micro-ATX form-factor. I mean, it works, but it could have been better. I’d like to think it’s because the market is a bit more limited in Australia, but it’s more because I’m not very good at this stuff.

Thirdly, if you do end up with the ASRock board, you’ll need to make a change to your grub configuration so that the board will boot headless. To do this, ssh or console onto the machine and edit /etc/default/grub. Uncomment GRUB_TERMINAL=console (by removing the #). You’ll then need to run update-grub and you should be right to boot the machine without a monitor connected.

Finally, the OMV experience has been pretty good thus far. None of these roll-your-own options are as pretty as their QNAP or Synology brethren from a UX perspective, but they do the job in a functional, if somewhat sparse fashion. That said, having been a QNAP user for a about 7 years now, I remember that it wasn’t always the eye candy that it is nowadays. Also of note, OMV has a pretty reasonable plugin ecosystem you can leverage, with Plex and a bunch of extras being fairly simple to install and configure. I’m looking forward to running this thing through its paces and posting the performance and useability results.



FreeNAS – A few notes

Mat and I have been talking about FreeNAS a lot recently. My QNAP TS-639 Pro is approaching 7 years old and I’m reluctant to invest further money in drives for it. So we’ve been doing a bit of research on what might be good hardware and so forth. I thought I’d put together a few links that I found useful and share some commentary.

Firstly, FreeNAS has been around for a while now, and there is a plethora of useful documentation available via the official documentation, forums and blog posts. While digging through the comments on a post I noticed someone saying that the FreeNAS crowd like to patronise people a lot. It might be a little unfair, although they do sometimes come across as a bit dickish, so be prepared. It’s like anything on the internet really.

Secondly, most of the angst comes about through the choices people make for their DIY hardware builds. There’s a lot of talk about ECC RAM and why it’s critical to a decent build. I have a strong dislike of the word “noobs” and variants, but there are some good points made in this thread. Brian Moses has an interesting counter here, which I found insightful as well. So, your mileage might vary. For what it’s worth, I’m not using ECC RAM in my current build, but I am by no means a shining light when it comes to best practice for IT in the home. If I was going to store data on it that I couldn’t afford to reload from another source (I’m using it to stream mkv files around the house) I would look at ECC.

Thirdly, one of the “folk of the forum”, as I’ll now call them, has a handy primer on FreeNAS that you can view in a few different ways here. It hasn’t been updated in a little while, but it covers off a lot of the salient points when looking at doing your own build and getting started with FreeNAS. If you want a few alternative approaches to what may or may not work for you, have a look at Brian’s post here, as well as this one and this one. Also, if you’re still on the fence about FreeNAS, take a look at Brian’s DIY NAS Software Roundup – it’s well written and covers a number of the important points. The key takeaways when looking at doing your own build are as follows:

  • Do your research before you buy stuff;
  • Don’t go cheap on RAM (ECC if you can);
  • Think about the real requirement for ZIL or L2ARC; and
  • Not everyone on the internet is a prick, but sometimes it will seem like that.

Finally, my experience with FreeNAS itself has been pretty good. I admit that I haven’t used FreeBSD or its variants in quite a few years, but the web interface is pretty easy to navigate. I’ve mucked about a bit with the different zpool configurations, and how to configure the ZIL and L2ARC on a different drive (that post is coming shortly). The installation is straight forward and once I got my head around the concept of jails it was easy to setup Plex and give it a spin too. Performance was good given the hardware I’ve tested on (when the drives weren’t overheating due to the lack of airflow and an Aussie summer). I’m hoping to do the real build this week or next, so I’ll see how it goes then and report back. I might give NexentaStor Community Edition a crack as well. I have a soft spot for them because they gave me some shoes once. In the meantime, if anyone at iXsystems wants to send me a FreeNAS Mini, just let me know.

EMC – DIY Heatmaps – Updated Version

I’ve patched the DIY Heatmaps script, fixing a problem with the table names generated in the database files. You can download it from the Utilities page.




EMC – DIY Heatmaps – Updated Version

Mat has patched the DIY Heatmaps script, fixing a problem with current model VNXs and updated naviseccli whereby using the –get_drive_type –display_drive_type options of the heatmap script would cause a JavaScript error in the resulting heatmap HTML file. You can download it from the Utilities page.

EMC – DIY Heatmaps – Updated Version

Mat has updated the DIY Heatmaps script to support SAS-type Flash drives. Download it from here, take it for a spin and let us know what you think. And tell your friends.

EMC – DIY Heatmaps – Updated Version

Mat has updated the DIY Heatmaps for EMC CLARiiON and VNX arrays to version 4.01. You can get it from the Utilities page. Any and all feedback welcome.

Updates and Changes to the script

  • Add database storage / retrieval for performance stats. The database size will be approximately 2.1 x the size of the NAR file based on the default interval of 30 minutes. On my PC it took a bit over 9 hours to process 64 NAR files into a database, the NAR files were 1.95GB and the resulting database was 4.18GB. However running the script over the database to produce a heatmap only takes seconds.
  • Changed to use temporary tables for transitional data.  This should slightly reduce the size of the database file, as the temporary data is not written to disk.
  • Changed the way the script processes multiple NAR files, the script previously bunched all NAR files into a single naviseccli process, this was problematic if you were processing multiple large NAR files, the script now processes them one at a time.
  • Add command line options:

–output_db                               Output the processed NAR file to the nominated database

–input_db                                  Use the nominated database as the source of data for the heatmap

–s_date                                       Specify a start date/time must be in the format (with quotes if specifying date and time “mm/dd/yyyy hh:mm:ss”

–e_date                                       Specify an end date/time

–retrieve_all_nar                     When retrieving NAR files from the array, you can now retireve all nar files (it wont overwrite files already downloaded)

–process_only_new                 If you are downloading NAR files, only process files that haven’t been downloaded previously

–max_nar_files                        Set the maximum number of files to download and process


Please let us know if you find any bugs or problems with the script, or if you have any further suggestions for changes and enhancements.



EMC – DIY Heatmaps – Updated Version

Mat has updated the DIY Heatmaps for EMC CLARiiON and VNX arrays to version 3.0211. You can get it from the Utilities page here. Any and all feedback welcome. Changes below:

Add –min_colour, –mid_colour, –max_colour options (just a change of spelling of colour)

Remove case sensitivity for colours

Added FC SSD drive type

EMC – DIY Heatmaps – Updated Version

Mat has updated the DIY Heatmaps for EMC CLARiiON and VNX arrays to version 3.020. You can get it from the Utilities page here. Any and all feedback welcome.

EMC – DIY Heatmaps – Updated Version

Mat has updated the DIY Heatmaps for EMC CLARiiON and VNX arrays to version 3.019. You can get it from the Utilities page here. Any and all feedback welcome.

Latest fixes:

· Search Path environment variable for naviseccli

· Search common install locations for naviseccli

· Improve cross browser support – tested on IE, Chrome and FireFox

· Improve debug details – add module version reporting

· Fix divide by zero bug in rendering routine

EMC – DIY Heatmaps – Updated Version

Mat has updated the DIY Heatmaps for EMC CLARiiON and VNX arrays to version 3.018. You can get it from the Utilities page here. Any and all feedback welcome.

Latest fixes:

## 0.3.016 Add options to add array name and SP name to output file

## Fix –display_drive_type so that it displays empty drive slots as white, Removed / Failed drives as gray and unknown as green

## Add attributes to display total array and bus IOPS and Bandwidth

## Add –display_actual option to view actual IO stats

## Add read and write attributes for SP IOPS and bandwidth metrics

## Add –time_zone option

## Add the time zone to the heatmap output

## Add LUN bandwidth total, read & write and LUN IOPS total, read & write attributes

## Fix display problem when all of trays have their last disks configured as hotspares or not in use

## Add 2TB drive size

## 0.3.017 Change display options to allow controll of how many Disk, LUN and SP heatmaps per column

## Add –disk_maps, –lun_maps and –sp_maps

## 0.3.018 Add –debug option to print detailed debug information