Chapter 4: Technology Background
103
RAID 1 – Mirror
When a RAID Volume is mirrored, identical data is written to a pair of disk drives,
while reads are performed in parallel. The reads are performed using elevator
seek and load balancing techniques where the workload is distributed in the most
efficient manner. Whichever drive is not busy and is positioned closer to the data
will be accessed first.
With RAID 1, if one disk drive fails or has errors, the other mirrored disk drive
continues to function. This is called
Fault Tolerance
. Moreover, if a spare disk
drive is present, the spare drive will be used as the replacement drive and data
will begin to be mirrored to it from the remaining good drive.
Figure 2. RAID 1 Mirrors identical data to two drives
The RAID Volume’s data capacity equals the smaller disk drive. For example, a
100 GB disk drive and a 120 GB disk drive have a combined capacity of 100 GB
in a mirrored RAID Volume.
If disk drives of different capacities are used, there will also be unused capacity
on the larger drive.
RAID 1 Volumes on SmartStor consist of two disk drives.
If you want a mirrored RAID Volume with more than two disk drives, see
“RAID 10 – Mirror / Stripe” on page 105.
1
2
3
4
1
2
3
4
Data Mirror
disk drives
Summary of Contents for SmartStor DS4600
Page 1: ...SMARTSTOR DS4600 Product Manual Version 1 0 ...
Page 6: ...SmartStor DS4600 Product Manual vi GNU General Public License 137 Index 139 ...
Page 24: ...SmartStor DS4600 Product Manual 18 ...
Page 48: ...SmartStor DS4600 Product Manual 42 RAID 10 4 drives ...
Page 50: ...SmartStor DS4600 Product Manual 44 Click the Next button D to continue ...
Page 54: ...SmartStor DS4600 Product Manual 48 Figure 7 SmartStor file structure viewed from a MAC ...
Page 70: ...SmartStor DS4600 Product Manual 64 10 Click the Add button ...
Page 76: ...SmartStor DS4600 Product Manual 70 5 Click the folder whose contents you want to backup ...
Page 95: ...Chapter 3 SmartNAVI 89 Optional ...
Page 96: ...SmartStor DS4600 Product Manual 90 To view a photo click the View icon ...
Page 142: ...SmartStor DS4600 Product Manual 136 5 Boot the SmartStor See Connecting the Power on page 9 ...