Raid 5 online expansion

[azev]

Looking to build a home file server with 12 sata drives. Speed is not so important, but redundancy is. So I am thinking of getting a 12port sata card, probably used 3ware or high point, also external case with sata hot swappable bay. I am thinking of getting a six 400GB sata drive running in raid 5 config. This way I have 6 more room for expansion. My question is, let say my raid is full and I'd like to perform online expansion and add 2 more 400GB drives, what are the drawback of this method ? Does this have alot of risk of corrupting the existing data ? will performance get reduced after the online expansion is completed.
My plan is to add one drive as needed and possibly more sata case and raid controller when I populate all 12 sata slots. what do you guys think?? comments ??

Thx

 

[RaiderJ]

I don't know that there is a controller out there that let's you dynamically add hard drives to a RAID 5 setup. However, I'm up for being proved wrong, as this would be a worth controller for my RAID 5 setup as well!

 

[azev]

If I wasnt mistaken that feature is called Online Expansion, and most of the new multiport sata controller have this feature.

 

[GrammatonJP]

Almost all the scsi raids has this option standard... My last 3ware 8500 did not.

You can expand the logical partition of the RAID array but that usually does not expand the data volume partiton, ie ntfs partitions

If you have a Logical drive of 200 gb, windows volume partition is also 200 gb.. controller will add the extra room so you might have 300 gb at the end. Windows would need something like partition magic to add the extra room in

or http://www.acronis.com/homecomputing/products/diskdirector/

http://searchstorage.techtarget.com/tip/1,289483,sid5_gci1024039,00.html

 

[Fullmetal Chocobo]

I have a Broadcom BC4852, and it lets me do online expansion and conversions. While it is doing the conversion, the data is backed up either before or after the process, so you aren't really at risk. The only time you are at risk in that situation is when you are recovering from an error, such as rebuilding the RAID 5 array after one disk died. Since you are working off of the bare minimum, there is no redundancy at that point, until the RAID 5 array build is complete.