EN 16
RAID 0
• WhenaharddrivefailsinaRAID0,theRAIDfailscompletely.
• A RAID 0 Spanningoffersthepossibilitytouseharddriveswithdifferentcharac-
teristics.Thisisonlyagoodsolutionifthesaveddataisactuallyredundant.As
anarchiveof“oldharddrives”itisnotagoodsolution.Olddiskswilleventually
failandyourarchivewillbelost.
RAID 1
• ARAID1continuestoworkevenifoneharddrivefails.Thefaileddiskshouldbe
replacedassoonaspossibleasanotherdiskfailurewouldmeanacompleteloss
of all data. We recommend to perform a data backup before installing the new
hard drive. The exchange of a hard drive and the following rebuild of the data
usebothdrivesheavily–thereisariskfortheotherharddrivetofailtoo.
• The installation of a new hard drive triggers the rebuild of the data. You can
simplyputinthenewharddriveswhiletheotherarebusybutthesmooth
operationofaRAID1canbeinterruptedbythat.Therebuildingprocesstakes
several hours – it is dependent on size and processing speed of the hard drives.
It which means it cannot be seen on
theharddrives.Althoughthedrivecanbeusedduringtherebuildthiswilldelay
the process.
• The rebuild willnotstartwhendriveisactivelyaccessedorthedatacableisnot
connected.Ifyounoticethis,justturnoffthedevice,connectittoaPCandturn
it on again.
• A started and active rebuild will be carried out even with disconnected USB
cable.
• A disk failureissignalledbytheashingoftheredLED(Nr.12)onthefailed
disk.
• A rebuildofthemirrorissignalledbythelightoftheredLED(Nr.12)onthe
faileddisk.AtthesametimebothLEDs(Nr.11)arechangingcolourbetween
blueanpurpleandbothharddrivesareworkingpermanently.
• Hard drives age and will eventually fail.Theycanalsofail spontaneously due
to other defects.Whentheyare“identical”theywillreachtheirlifetime limit
around the same time.
Accordingtothiswerecommendfollowingstrategyforexchangingharddrives:
Hasoneharddrivefailedspontaneously,exchangethisoneharddrive.Hasthe
hard drive reached its lifetime limit (which differs from hard drive model to
modelanddependsontheintensityofusage),betterexchangebothharddrives
–aftercreatingabackup.ThisallowsforaRAID1systemwhichworksreliably
for a long time.
Hints for the Installation of Hard Drives with Data
Important: If you plan to remove hard drives from one system to install them into