Spanning Array over Multiple Controllers

[Infin1ty]

I couldn't find an answer, or perhaps didn't search well.
I was wondering if it's possible to create a raid array spanned over multiple controllers, for example taking 4 x MegaRAID LSI, and creating RAID10 array using disks on all the 4 controllers.
I know it's possible using software raid (for obvious reasons), but is it possible for example using with hardware raid (be it LSI, Adaptec, Areca, etc...)?

 

[mwroobel]

Areca SAS PCIe HBAs support spanning arrays over multiple adapters.

 

[Blue Fox]

Areca SAS PCIe HBAs support spanning arrays over multiple adapters.

Since when? I'm pretty certain they don't.

 

[mwroobel]

Well, the box I am sitting in front of right now has 2 1882-24 adapters, each with 1TB SAS Drives. Each adapter has 2 12 drive R6 volumes, and there is 1 striped volume encompassing all 4 R6 arays yielding a total of 40TB available space. Though this particular install isn't multi-adapter in that sense, You can also see multi-adapter support listed here http://www.areca.com.tw/products/pcietosas1680series.htm and here http://www.areca.com.tw/products/1880.htm

 

[Blue Fox]

Yes, it supports having multiple cards in one system, but I take it your striped volume is on the OS level? I never saw any options to span arrays across multiple controllers when I had multiple HBAs in each system.

 

[mwroobel]

Yes, it supports having multiple cards in one system, but I take it your striped volume is on the OS level? I never saw any options to span arrays across multiple controllers when I had multiple HBAs in each system.

Yes, it is not supported at the BIOS level, these are striped (as opposed to spanned) at the OS level. The last card that did array spanning (reliably) were the Raidcore series of boards from c. 2005 and later the broadcam controllers based on the Raidcore IP.

 

[Blue Fox]

Well, doing it on an OS level isn't really Areca exclusive. You can pretty much do that with any RAID HBA (even if they aren't the same)

 

[mwroobel]

Well, doing it on an OS level isn't really Areca exclusive. You can pretty much do that with any RAID HBA (even if they aren't the same)

Well, you can span across dissimilar arrays, but you can only stripe like arrays (meaning exact sizing.. Differences of a single meg will cause failure to create the volume.. Some cards support size truncation which makes it easier to match but in general like arrays are suggested.