You can use a global hot spare to automatically replace a failed physical disk in any redundant array as long as the capacity of the global hot spare is equal to or larger than the capacity of the failed physical disk. So in this case if any of the disk in RAID 6 is failed global hot spare will replace it till you replace failed drive with working one.
hi specialists,  here is what we are going to install: [IMAGE] perc H840 Raid adapter will be used for the MD1400, should we configure  global hotspare? what is the best practices? thanks and regards  
Raid6 with hotspare or not