RAID Migration & RAID Expansion
Posted by - NA - on 17 October 2016 10:29
Changing the number of disks or RAID level in current RAID configuration. The system will list the possible migration paths, and administrator can choose a possible path. For example, RAID 1 with 2 disks can be migrated to RAID 5 with 5 disks or RAID 5 with 3 disks can be migrated to RAID 5 with 4 disks.
RAID levels currently supported are : RAID 0, 1, 5.
The Migrate function is for change RAID Level or change RAID drive number, please refer below form
N4100PRO / N5200 / N7700 / N8800 RAID Migration
Firmware before 2.01.xx, offline migration available. During RAID migration, all services are not available.
RAID0 -> RAID0
Since firmware 2.01.08, we implement new "online migration", during migration, servers are still available.
RAID1 -> RAID5
1U4200XXX / 1U4600 / N0503 / N3200XXX / N4100PRO / N4200 / N4200PRO / N4200ECO / N5200XXX / N5500 / N7700 / N7700SAS / N7700PLUS / N7700PRO / N8200XXX / N8800 / N8800SAS / N8800PLUS / N8800PRO
In newer firmware (32bit 3.xx , 32bit 5.xx), we remove the offline migration function and only online migration available.
RAID1 -> RAID5
N4800 series / N5550 / N5810 series / N6850 / N7700PROV2 / N8800PROV2 / N8810U series / N8850 / N888U-10G / N8900 series / N10850 / N12000 series / N16000 series
In 64bit firmware, the migration option are available as following,
RAID1 -> RAID5 (Online) , require two more disks.
When larger disks have replaced the smaller disks thru RAID Rebuild, the file system on the RAID is not changed. Administrator can press this button to check to see if there is room to expand the file system. If yes, then the file system will grow to take advantage of the larger disks.
And RAID Expand is for expand each drive maximum capacity, for example:
Drive #1 750GB
The RAID 5 total available capacity is 500GB. The behavior is the same as 250GB*3, therefore the RAID5 capacity is 500GB.
Note: During offline RAID Migration and RAID Expansion, all the file services such as SMB/CIFS, AFP, NFS, and FTP will not be available. The time to finish these operations depends on the size of your hard disk drives and your RAID volume..
WARNING: RAID Migration and Expansion are inherently risky operations. Please make sure your system is protected by an UPS (Uninterruptible Power Supply) to prevent accidental power failure, which might result data loss.
WARNING: These operations will cause heavy loading on your RAID system. RAID Migration and RAID Expansion will not be available if your RAID is in degraded state.
In case drive #2 250GB was replaced with 750GB drive, the NAS will begin rebuild RAID, after RAID rebuild is finished, the total capacity still 500GB , but once execute RAID Expand, the RAID total capacity will increase to 1.5TB.
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