What Is RAID1m Anyway?
RAID1m refers to Vasstek's patent-pending process "Reliable Access in a Disk by Mirror 1." The controller essentially creates a real-time mirror image on a single disk, which allows data to be restored from its duplicate should original information become corrupted or unreadable due to bad sectors. This restoration function starts up immediately and allows for uninterrupted workflow. It's not just partition data that's protected; the controller also backs up the primary boot sector. Creating the mirror isn't without its price in terms of a storage hit with the RAID1m process effectively halving the volume's available space.
To inform users of sectors gone awry, Vasstek has incorporated a proprietary application known as the "VASSTEK Advanced Disk Indicator" (VADI) which runs minimized in the taskbar. This utility immediately informs users when bad sectors occur and continues to provide file access by reading data from the mirror. VADI also records the history of bad sectors, which allows for evaluation of whether your internal storage requires secondary backup or drive replacement.
We choose a 400 GB Samsung HD400LJ as our test drive. The size halved by the RAIDm1 mirror gives us a resulting capacity of 200 GB, which is what many desktops offer.
Our drive did not have any errors so the VADI table was empty.
Vadi Hard Disk Information:
HD Model: SAMSUNG HD400LJ
HD Size (MB): 190745
HD Mode: RAIDm1 Mode
Total Bad Sectors:
counting of bad sectors = 00
Bad Sector History:
LBA address time
I'm sure most of you are shaking your heads as to why one would create a backup solution by choosing to write to the same drive. We did this to see what the performance hit would be from the write process when the mirror was intrinsic to the volume. Let's take a look at the benchmarks.