Keep Drive Spinning



Every time I close the lid on my macbook air, my external hard drive seems to spin up for about 5 seconds every 30 seconds, and this will go on continuously, even for several hours. The noise itself isn't too loud, so I don't really have a problem with that, but I'm worried it might damage the hard drive. Keep Drive Spinning Makes sure that a selected drive does not go to sleep unexpectedly. For use with certain external drives that don’t respect Mac OS X’s power management settings. Current version: 3.0.

Keep
Areca ARC-8050 8-Bay Thunderbolt to 6Gb/s SAS RAID Storage

In my last post I reviewed external thunderbolt storage devices for our Imac capture station, none of which worked correctly. I came across this Areca 8 bay box on the OWC website. This looked more “promising” than the Pegasus R6 :) sorry Promise Tech…had to do it. Costs around $1500/free shipping. Price is very close to the Pegasus R6 when you take into account 8 bays vs 6 bays. Its empty which is how I would prefer it anyway. Lets me use my existing drives. Here are some quick specs from Areca’s website:

  • The ARC-8050 incorporated on-board high performance dual core 800Mhz ROC storage processor and with 1GB DDR3-1333 SDRAM memory on-board to deliver true high performance hardware RAID.
  • Bootable
  • RAID level 0, 1, 1E, 3, 5, 6, 10, 30, 50, 60, Single Disk or JBOD (just a bunch of disks aka passthru)

Check out their website, they have it all spelled out. Some of the other manufacturers don’t have real detailed spec sheets showing whether they are bootable, JBOD capable, etc. Areca’s was pretty clear. The drive trays have mounting holes for 2.5″ and 3.5″ drives. Seems like a nice piece of hardware.

There were a couple of hiccups to get it going, which ended up being a default being set incorrectly. But from the first time it started up, there was a noticeable difference in operation and a feeling of reliability. The Pegasus box was just the opposite.

We’ve had it running for about two months and haven’t had any issues. In the first bay we placed a 90 GB 6G SSD OCZ Vertex 3 to run the OS (running around 400 MB/sec read & write). The next bay has a HST 4 TB Time Machine SATA drive. Next bay is empty (may use for hot spare or add another drive to the RAID 5 array). Then we have 5 2TB Hitachi SATA HD’s in a RAID 5 setup (these will be used for working still and video files, running around 415 MB / sec read & write).

Arc-8050 Thunderbolt rear view

I still don’t trust the RAID 5 as a single solution for storage and backup. You still need at least two other copies of all data you don’t want to lose, one of which off site at all times.

Here is the iMac machine specs we are using:

Keep Drive Spinning For Mac

Keep hard drive spinning
iMac 27 inch, Late 2012

Our first attempt at RAID 5 with factory defaults and using their Quick Function > Quick Create option was not successful. The ARC – 8050 would start to initialize for an hour or so then freeze at exactly 5.6%. The box would freeze and crash the iMac. Fun. Now this product just started shipping so they will get cut some slack. The problem was also resolved quickly. See below.

Long story short, after emailing Areca’s tech support over then next couple of days and running some more tests we found a fix. Under System Configurations >Disk Write Cache Mode needs to be set to Disabled, not set to SAS and SATA (which is the default). After changing that it initialized properly the first time and haven’t had any problems since.

Drive
Disk Write Cache Mode
Keep Drive Spinning

If you are looking for a fast external thunderbolt enclosure with all of the bells and whistles…this appears to be the ticket…for now at least.

Jordan

June 2013

Why Is Hard Drive Spinning

The hard disk firmware is programmed to go into powersave mode on boot up. What you'll need to do is send the ATA commands to not stay in powersave mode, or like you said, give it dummy commands.
There is info over at PJRC on how to interface a PIC with an IDE drive, but it requires about 20 bits of IO to do it: http://www.pjrc.com/tech/8051/ide/wesley.html .
To do this in code, you'll need to (and this is all speculation based on reading the docs):
1] Read the status register until it indicates READY
2] Write 0xE3 to the command register
#1 is probably unnecessary. The write cycle looks like you need to set the following bits (copied from docs):
/CS0=0, /CS1=1, A2..A0=111B, D0..D7=0xEH - set write to command register with 'no Idle spindown' command
Then pulse the /WR pin low
The easiest way may just be to hook it up to a computer that allows you to set the idle times in BIOS, and do that. See if it saves it permanently.