R10 Mode - Sans Digital Towerraid TR4UT-B Detailed User Manual

Although the volume remains available during the rebuild process, the volume is susceptible to data loss through damage to
the remaining drive until redundancy is restored at the end of the rebuild and verification process. Host access takes
precedence over the rebuild process. If you continue to use the R1 volume during the rebuild, the rebuild process will take
a longer time to complete, and the host data transfer performance will also be affected.
TR4UT / TR4UT-B

2.6 R10 MODE

The R10 MODE storage policy combines the features of both R0 and R1. Performance is provided through the use of R0
MODE, while adding the fault tolerance of R1. The implementation of R10 requires four drives. The drives are assigned as
two sets of striped pairs. The data is written to R1 set and provides data redundancy. Alternating blocks of data are then
striped (R0) across another R1 set. This provides improved speed. The resulting storage capacity of the virtual R10 volume
will be two times of the smallest drive.
If one drive fails, the R10 volume is still usable, but it is in a vulnerable state because its mirrored hard drive is inaccessible.
When the offline drive comes back online, the appliance begins a rebuild process immediately to restore data redundancy. A
message appears in the LED indicator to notify you that a rebuild is in progress.
Although the volume remains available during the rebuild process, the volume is susceptible to data loss through damage to
the remaining drive until redundancy is restored at the end of the rebuild and verification process. Host access takes
precedence over the rebuild process. If you continue to use the R10 volume during the rebuild, the rebuild process will
take a longer time to complete, and the host data transfer performance will also be affected.
TR4UT / TR4UT-B
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