Tag Archives: TrueNAS

Seagate Exos disks in TrueNAS Core: Disable parking of heads

Technical Stuff, ,

My NAS (TrueNAS Core) is running with Seagate Exos X16 drives. Those were considerably cheaper than any other drive at the time of purchase (September 2020) here in Germany. From what I gathered  since then, this is often still the case, also in other countries.

But there is one aspect about these drives that needs attention. Being marketed for data center use, they have a very small timeout for parking their heads. So, if an Exos drive is idle for only a very short time, it will move its heads into a parking position. That is a reasonable setting for data centers, where drives are hardly ever idle. But for a small business or home use it is less than ideal.

Fortunately, this setting can be changed and TrueNAS Core, or rather the underlying FreeBSD, has the right program for this already installed. Below you find the command that I am using. You will need to adjust the device, but otherwise you can just run it.

camcontrol epc /dev/??? -c state -d -p Idle_b -s

In terms of the ATA level, this disables the Idle_b power condition and saves it to the drive to survive a reboot. For more details, please check out the extensive man page of the camcontrol command.

In addition I recommend that you configure your system to issue this command on every startup. Under normal conditions that is not necessary. But what if you need to replace a disk drive? If you have a case with hot-swappable drive bays, this will of course not help. In that case I would think about a cron job.

My Journey with Data and Backups

Technical Stuff, , , , ,

I started with PCs in 1990 on a 286 with a 42 MB hard disk (Seagate ST251-1), which about one year later had issues with faulty sectors. This was a couple of years before (consumer) hard disks started to internally re-map bad sectors. And it was also the first and last time that I lost data. Ever since, I have been paranoid about backups (and more importantly restores).

I started with simple floppy disks for source code, spreadsheets, etc. and went for a DAT streamer in 1996 (HP C1536). This only lasted 3 years and after that abysmal experience I switched to a QIC streamer (Tandberg SLR-24), which lasted until about 2008. Well, that’s when I took it out of service.  It was in perfect working condition but 12 GB capacity per cartridge started to be an issue. Since then I have used hard disks in various ways, since streamers have become a prohibitive upfront investment for me. I would still prefer streamers, but that is a different story.

All the people I know (incl. at work) initially think of my efforts as overkill. Until they loose 10 years of digital pictures, esp. when their children are involved. That is when they are willing to invest time and money. The same goes for many companies, unfortunately. A friend told me about a malware attack on his employer about a year ago. All of a sudden there was budget for keeping backups longer than just 30 days, a properly segmented network, and other things their IT department had wanted for more than a decade. Everybody (incl. me – see above) has to learn this the hard way, I guess.

A side note on NAS gear that is typically more in the consumer space. I am currently in the process of switching to a new FreeNAS box. There were long deliberations as to whether I should go for Synology instead. The core reason why I stayed with FreeNAS is that it I have flexibility. From a usability and ease-of-use perspective I got the impression that Synology is (far?) superior. But that comes at the price of limitations. A mass market product needs to keep support tickets under control and the only way for that is to constrain people’s options. And I wanted to stay flexible, even if that meant to spend more money (hardware specs are considerably higher than the Synology model in question) and time for setting things up.

Finally, I am not going for TrueNAS 12 right now but start with FreeNAS 11.3 U5. Yes, I have seen and read many highly positive comments about v12 and how stable it is. But IMHO nobody can be really sure for at least a couple of weeks that no hidden errors exist.