Promise Technology 2-Year Extended Warranty for VessR2000 RAID Head - Manual (Page 596)

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Product Manual Technology Background
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M
igratioN
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.
M
igrAtiOn
r
eQuireMents
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.
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evels
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.