SHARKOON 8-Bay RAID-Station - Manual (Page 25)

8-bay raid station 25
Advantage/disadvantage:
The R50 mode uses less capacity for protection and is the preferred method to reduce
the cost per megabyte for larger installations.
In exchange for low overhead necessary to implement protection, the R50 mode degrades
performance for all write operations. The parity calculations for R50 mode may result in
write performance that is somewhat slower.
The resulting storage capacity of the virtual R50 volume will be “n minus 2”-times
(n=number of disks) of the smallest drive capacity.
If one drive fails, the virtual R50 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. During
this procedure the LED indications will notify you that a rebuild is in progress.
Notes:
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 virtual R5 volume during the rebuild,
the rebuild process will take a longer time to complete, and the host data transfer
performance will also be affected.
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