Greetings unRAID forum,

 

As a soon to be former server admin, I've had years to play with all kinds of fun devices, softwares, and configs. Well, as of tomorrow, I'll no longer have access to the readily available enterprise test licenses for my home data center playground. *sigh*

 

So, I've begun looking for free/affordable alternatives some of my trusty apps. In looking into unRAID, I like the all-in-one management but it seems some of my hardware I've accumulated won't be accessible. My last shop was an HP shop that turned big blue (IBM). So, a number of lightly used HP DL's and a very nice HP MSA2324sa (DAS connection via SAS controller HP AJ808A) came into my possession.

 

First thing I read, was that the HP Smart Array RAID cards won't work. Not a problem. I've already checking with another sys admin friend of mine who has a few M1015s sitting around. He's even tried the LSI flashing successfully. So, we've got that taken care of, but in some initial testing the storage shelf (MSA) isn't recognized.

 

I configured a test vdisk and made sure the bios was able to see it, but once unRAID boots, it's not available for assignment. Bummer!

 

So, now that I've shared all that with you, let's get to the question. Why no RAID card or MSA support? I'm curious. What's the technical reasoning behind the inability to present a raided set of disks to unRAID as a single drive for assignment? I've read plenty of posts saying you can't, but none that really get into the dirty "why" details. Just looking for some education.

 

Thanks to whoever reaches out,

-SG

The short answer is that UnRaid is a software raid solution, not hardware, therefore the disks are presented to the system individually in a JDOB fashion and the UnRaid software uses the largest disk for parity and created the software raid volume from the remaining disks in the array. There are no limitations to the sizes of disks you can use in your UnRaid array, they don't have to be the same size or model as they do in standard hardware raid setup. You don't have the many choices of raid levels with UnRaid and currently a single parity drive is the only option, although dual parity is supposed to be coming in the next big update 6.2 which is rumoured to be coming 'soon'.

Note that if the RAID card handles the drives completely locally and presents itself as if it were a single drive to unRAID then it can be used (I have done this before).    However as there are no RAID related drivers in unRAID this has to be handled completely locally by the card including any recovery if a disk fails.  Also the card must not need any special drivers it needs to work with generic SATA/SAS drivers.  As unRAID runs completely from RAM only a limited set of drivers are included.

Use the best...Areca. 

I have an older Areca and its great, but its a little expensive if you are only going to do JDOB, while my card can support 16 drives, there are cheaper options for 8-12 drives out there.

Thanks for the replies everyone.

 

@bubbaQ or @ashman70: Got the model numbers for those Arecas handy?

 

-Doug

Mine is a 1261, works great, has a BBU, I was using it in a raid 5 config until I switched over to UnRaid, I currently have 2, 3, and 4TB SATA drives hanging off it with no issues.

I have an older Areca and its great, but its a little expensive

You can find some amazing buys on eBay.

For sure you can, no question, if shipping doesn't kill you though. Being in Canada, shipping always usually hurts.

ARC-1883ix-16-8G and an older ARC-1880ix-16-4G

 

Thanks for the replies everyone.

 

@bubbaQ or @ashman70: Got the model numbers for those Arecas handy?

 

-Doug