Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have a QNAP TS-239 Pro II+ with 2 x 2 TB HDDs in RAID1. I'm running 3.6.0 Build0210 firmware. I access the NAS from my iMac (OS X 10.7.x). The NAS HDDs are formatted as ext4.

I'm sitting at about 90% capacity now and before it gets any fuller I'd like to sort things out. In the future, I will opt for two single HDDs as opposed to a RAID1 setup as HDD prices are absurd these days and I don't require what RAID1 offers me.

In the meantime, I wonder if I can pull one of the HDDs and still use the NAS? What I plan on doing is:

  • Removing HDD2.
  • Placing HDD2 in a dock and formatting it as HFS+ for use with my iMac.
  • Turning on the NAS with only HDD1 in it.
  • Copying the data from HDD1 --> HDD2.
  • Waiting for HDD prices to drop to reasonable levels.
  • Putting in 2 x 3 TB HDDs and using them as single drives, as opposed to RAID1 (or RAID0).
  • Copying the data from HDD2 to the 2 x 3 TB HDDs.

Will the NAS work with one of the mirrored copies absent?

Many thanks.

share|improve this question
Safest bet is Not to use the NAS enclosure to mount the drive with data, use 2 docks, its not worth risking data loss, no way to know for sure how the NAS handles a missing drive, probably allows access to a single drive but is risking your data worth an experiment? and as Iceking007 said, configuring the NAS to run as non raid and putting the data drive in may cause the NAS to auto format the drive. – Moab Mar 2 '12 at 4:42
up vote 1 down vote accepted

Yes a RAID1 system is a mirrored array inwhich both drives contain the exact bit for bit data for the chance that one drive fails, all your data is intact.

You will have no problem removing one drive the other will function completely independent and your data will be intact for the life of the drive. Once you replace the removed drive the controller will rebuild the RAID1 configuration/integrity. Depending on the controller you may be able to turn off the RAID and use the two drives/bays independently however if you do not the controller will automatically reformat any drive; any data being erased and write the backup/RAID.

Hope that helps you out.

share|improve this answer
Thanks very much. Just the info I was after. – boehj Mar 2 '12 at 11:30

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .