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Expanding Raid 5 Array on HP Smart Array 500 SAN

The current setup is a Raid 5 Array with 10 72.8 GB 10,000 RPM drives, all in an HP Smart Array 500 SAN.  I will be expanding the array with four more 72.8 GB drives.  Currently there is only 30 GB of free space in the array.  My question is how long will this operation take?

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imsmis
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imsmis
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huntersvcsCommented:
Hardware-RAID

The time for the expansion depends on the controller model, the hard disks used, the number of them and the speed of the SCSI bus.

Software-RAID

RAID-5 regions can now be resized by adding new objects to the region or removing objects from the region. The data in that region will be "re-striped" to account for the change in number of child objects.  To prevent data corruption, this operation must be performed while the region is unmounted and deactivated.

Be forewarned, the expand and shrink process can take a *long* time. During the "re-striping" process, each chunk of data in the RAID region must be moved from it's current location to it's new location. During initial tests, it seems that a larger RAID chunk-size will decrease the time necessary to complete an expand or shrink. Unfortunately, the chunk-size cannot be changed after the RAID region is created. If you are creating new RAID regions that you might want to expand or shrink in the future, you might want to consider a larger chunk-size.

IMPORTANT: Please have a suitable backup available before attempting a RAID-0 or RAID-5 resize. If the expand or shrink process is interrupted before it completes (e.g., the EVMS process gets killed, the machine crashes, or a disk in the RAID region starts returning I/O errors), then the state of that region cannot be ensured in all situations.

**DO NOT INTERRUPT THE RESIZE PROCESS BEFORE IT FINISHES**.

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imsmisAuthor Commented:
Thanks for all the info, huntersvcs
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