User Manual

Chapter 8 Storage Manager
Cloud Storage User’s Guide
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GB and 250 GB respectively in one RAI D 5 array, then the m axim um capacity is 450 GB ( 3 * 150
GB, the sm allest disk size) and t he rem aining space ( 300 GB) is unused.
Typical applicat ions for RAI D 10 are transact ion processing, relat ional database applicat ions,
ent erprise resource planning and ot her business system s. For write- int ensive applicat ions, RAI D 1
or RAI D 1+ 0 are probably bet t er choices, as t he perform ance of RAI D 5 will begin to substant ially
decrease in a w rit e-heavy environm ent .
Hot-spare
A RAI D 1 or RAI D 5 array with a hot- spare operates as a three- disk RAI D 1 or RAI D 5 array with t he
fourth disk on standby. The st andby disk aut om at ically com es int o play if a disk in the array fails.
The advantage of a hot- spare is t hat if a disk fails, t hen t he array resynchronizes aut om atically wit h
the st andby disk and operates at healt hy array speed aft er the resynchronization.
Note: You need four hard disks installed t o use RAI D 10, RAI D 5 or RAI D 5 with hot-
spare.
RAID and Data Protection
I f a hard disk fails and you’re using a RAI D 1, RAI D 10, or RAI D 5 array t hen your data will st ill be
available ( but at degraded speeds until you replace the hard disk that failed and re-synchronize the
array) . However, RAI D cannot protect against file corruption, vir us att acks, files incorrectly delet ed
or m odified, or the NAS m alfunct ioning.