Rai D 1 - Mirror - NUUO NVRmini 2 User Manual

I f disk drives of different capacit ies are used, t here will also be unused
capacit y on t he larger driv es.
Because RAI D 0 does not offer Fault Tolerance, m eaning t hat y ou cannot
recov er y our dat a aft er a disk driv e failure, we do not recom m end a RAI D 0
Volum e for y our unit .
RAI D 0 Volum es on t his unit consist of one or m ore disk driv es.
RA I D 1 – M i r r o r
When a RAI D Volum e is m irrored, ident ical dat a is writ t en t o a pair of disk
driv es, while reads are perform ed in parallel. The reads are perform ed using
elevat or seek and load balancing t echniques where t he workload is dist ribut ed
in t he m ost efficient m anner. Whichev er driv e is not busy and is posit ioned
closer t o t he dat a will be accessed first .
Wit h RAI D 1, if one disk drive fails or has errors, t he ot her m irrored disk drive
cont inues t o funct ion. This is called Fault Tolerance. Moreov er, if a spare disk
driv e is present , t he spare driv e will be used as t he r eplacem ent driv e and dat a
will begin t o be m irrored t o it from t he rem aining good driv e.
The RAI D Volum e's dat a capacit y equals t he sm aller disk drive. For ex am ple,
a 100 GB disk drive and a 120 GB disk driv e hav e a com bined capacit y of 100
GB in a m irrored RAI D Volum e.
I f disk drives of different capacit ies are used, t here will also be unused
capacit y on t he larger driv e.
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