User Manual

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Product Manual Technology Background
raid leVel MigratioN
The term “Migration” means either or both of the following:
• ChangetheRAIDlevelofalogicaldrive.
• Expandthestoragecapacityofalogicaldrive.
On Vess, RAID level migration is performed on the disk array but it applies to the logical drives. Migration does
not disturb your data. You can access the data while the migration is in progress. When migration is done, your
disk array has a different RAID level and/or a larger capacity.
MigrAtiOn reQuireMents
The following conditions affect RAID level migration:
• Thediskarrayandlogicaldrivemustshowagreencheckicon.
• TheTargetdiskarraymayrequiremorephysicaldrivesthantheSourcediskarray.
• IftheTargetdiskarrayrequiresanEVENnumberofphysicaldrivesbuttheSourcediskarrayhasanODD
number,ADDaphysicaldriveaspartofthemigrationprocess.
• Youcannotreducethenumberofphysicaldrivesinyourdiskarray,eveniftheTargetdiskarrayrequires
fewerphysicaldrivesthantheSourcediskarray.
• RAID1(mirroring)workswithtwodrivesonly.Onlyasingle-driveRAID0diskarraycanmigratetoRAID
1.OtherRAIDLevelsusetoomanydrivestomigrate.
• YoucannotmigrateadiskarraywhenitisCriticalorperformingactivitiessuchasSynchronizing,
Rebuilding,andPDM.
• ForRAID6orRAID60,youcanonlymigratebetweenthesetwoRAIDle-vels.DestinationRAID60axles
canhaveupto16physicaldrives.Otherlimitationsmightapply.
sOurce And tArget rAid levels
The tables on the following pages show the migration options for each source logical drive by its RAID level.
The available target RAID levels are shown with their requirements.