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matrix563
03-15-2009, 11:23 AM
according to a areca product brief:

The ARC-1280 RAID HBAs can also provide RAID levels 0, 1, 10, 3, 5, 6 or JBOD for maximum configuration flexibility. Its high data availability and protection derives from the following capabilities: online RAID capacity expansion, array roaming, online RAID level/stripe size migration, global online spare, automatic drive failure detection, automatic failed drive rebuilding, disk hot-swap, online background rebuilding, instant availability/ background initialization, auto reassign sector and battery backup and redundant flash image. Greater than 2 TB support allows for very large volume set application in 64-bit environment such as data-mining and managing large databases.

does this mean i can start a 8 drive array and add the rest of the drives later and make the array bigger on the fly without destroying the old array? if so then i can start buying the drives now!!!

i am aware if this is possible that having the array full will make this take a long long time, however, i will have usb backups just in case anything goes wrong.
http://www.areca.us/news/pdf/Arecacasestudy.pdf

found this too:

Capacity expansion is only permitted to proceed if all volumes
on the RAID set are in the normal status. During the expansion
process, the volume sets being expanded can be accessed by
the host system. In addition, the volume sets with RAID level 1,
10, 3, 5 or 6 are protected against data loss in the event of disk
failure(s). In the case of disk failure, the volume set changes
from “migrating” state to “migrating+degraded“ state. When the
expansion is completed, the volume set would then change to
“degraded” mode. If a global hot spare is present, then it further
change to the “rebuilding” state.

Volkum
03-15-2009, 02:17 PM
does this mean i can start a 8 drive array and add the rest of the drives later and make the array bigger on the fly without destroying the old array? if so then i can start buying the drives now!!!

Yes. However, be aware that OCE takes quite a while and you should only ever do one drive addition at a time.

Blue Fox
03-15-2009, 03:51 PM
Going from 12 to 16 drives (1TB Seagate 7200.11s) took 36 hours if I remember correctly. If you have a drive failure during expansion, you have to continue expansion and then rebuild the array, so you definitely want to back up your data.