Saturday, 28 April 2012

When is the image file of the entire RAID array useful?

Creating an image might be useful if one of these conditions are met

  1. The drives are connected via USB and power failures occur often. ReclaiMe + RAID recovery pair operates using "disk paths", and paths for USB drives may change on reboot. So you will need to redo the RAID part every reboot.
  2. One of the RAID member disks has a bad sector, or is otherwise damaged. In this case, it is best to create an image of the suspect disk first, even before you start with RAID recovery.
  3. The filesystem on the array is damaged, and you want to try some other data recovery tool on it.

Other than that, the image of the whole array is a waste of disk space. With a large array, you have to be careful what you are placing the image file onto. You should be acutely aware of the image file size. While most filesystem specifications say 12TB single file is acceptable, you will find that in practice, there is a limited set of configurations which accept files that big. By the way, this is where ReFS comes in handy even though it is still in beta.

Saturday, 14 April 2012

QNAP reboot

Always remember that

as the uptime grows, the chance of not being able to restart susccessfully increases.

That is, unless you take some special precautions.

Had an UPS fail on our QNAP, like a couple of days ago. Before that, the uptime was something like several months. Lo and behold, the QNAP failed to come back online. It just sit there "SYSTEM BOOTING >>>" with all the drive LEDs blinking, no ping, nothing, and looked very much like a power supply failure. However, all the LEDs were blinking, and generally it look very busy doing something for about 30 hours I let it sit. When I finally get around to connect a VGA to it, there was nothing to be seen.

Then, a couple of hard reboots took care of the problem, at least for the time being.
Looks like next time the PSU has to be replaced.

Monday, 9 April 2012

ReFS recovery

We now have ReFS recovery capability in our ReclaiMe data recovery software ( Obviously, this is not the final version, because the filesystem is not officially released yet. However, ReclaiMe works farily well against the current Windows 8 Server beta build.