unRaid using Areca based R6 as single drive


Recommended Posts

I am considering unRaid as a new network appliance.  I am really most interested in having it run SageTV now that it is open source and the SageTV open source developer community seems most focus on enabling it to run on an unRaid server.  I don't need unRaid's raid feature, as I have a spare Areca 1680-16 RAID card. 

 

I saw some posts about using Areca cards to give you more sata ports but, I am wondering if I can just let my Areca card manage the RAID6 array and just expose it as a single large disk to the unRaid OS?  If the answer is yes and it will just treat this as a 1 Port, single data disk, then great.  But will it instead see it as 8-16 ports if I have that many devices in the Areca Array?  Lastly, if I expand the Areca RAID 6 array by adding more disks, will unRaid be all well and good when the "single" RAID6 data disk grows from 10-->14 TB or will it ignore the additional capacity, or worse some how stop working?

 

thanks,

 

mv

Link to comment

This question was asked and answered in the thread below.

 

HellDirver - although unRAID cannot manage a RAID array, unRAID can include a RAID array from a hardware RAID card (at least from certain ones) as a single disk as I describe in the post below.

 

 

Link to comment

I'm currently using an Areca card with 2 4tb WD Red drives in a Raid 0 array for my parity drive in my main system, with 8 other drives in pass-thru mode on the card.  Unraid sees the raid array as a single 8tb drive (I did this due to the speed of the 8tb drives I'm using, which are the Seagate Archive drives).  The system currently has 35tb in it, but I have 2 more 8tb drives to add when I move it all over to my new box (Cisco UCS C200 M2 with a Dell MD1000 raid array, just waiting on my drive trays to show up).

 

The Areca cards work pretty well with Unraid (I've had no troubles), but aren't 100% supported.  You'll need to check the thread here about how to get it set up, and you won't get accurate drive temp readings, or proper spinup/spindown management from Unraid (but what's built into the card does work).  I'm moving to a different card on the new system since I need external ports for the MD1000 (LSI9201-16E), but the Areca has worked well for me for the last 2 years or so.  Just wish it had better support in Unraid.

 

Link to comment

Looks like we're approaching a point where the attractiveness of unRAID is more it's docker, plugin and ease of use over the fact you can plug in all the drives.

 

I'm still a huge fan of the Areca cards mainly for their network port and network management functionality.  I started with the ARC-1170 in a Dell server then moved to the ARC-1261ML.  I have a pair of ARC-1280ML cards I will eventually put into service whenever I get around to it.

 

For the OP, unRAID will work for your purpose.  The disadvantage of running R6 is you must use similar size drives and they must all keep spinning.

Link to comment
1 hour ago, earthworm said:

Looks like we're approaching a point where the attractiveness of unRAID is more it's docker, plugin and ease of use over the fact you can plug in all the drives.

Err, I think it's great that unRAID can make use of hardware RAID (especially for parity) for those who are interested.  But personally I've got zero interest in implementing hardware RAID and I'm still plenty interested in unRAID as a fault tolerant NAS (and an application platform).

Edited by tdallen
Link to comment
Just now, tdallen said:

Err, I think it's great that unRAID can make use of hardware RAID (especially for parity) for those who are interested.  But personally I've got zero interest in implementing hardware RAID and I'm still plenty interested in unRAID as a NAS (and an application platform).

 

The main reason I went with the Areca card initially was the port density/dollar of the older cards.  I didn't intend on using any of the raid functionality (and didn't for quite a while).  Once the 8tb Archive drives came out, and I bought a few, I wanted a faster alternative to using one for parity, and had 2 WD Red 4tb's here.  I set them up in a striped array as a single 8tb drive, and use it for the parity drive on the system.  I could just buy a faster 8tb drive now, but at the time, the Archives were the only game in town (and the 8tb non-archive drives are still somewhat pricey).  The nice thing about Unraid is it'll take the drives either way, passed through, or in an array.  

Link to comment
On 5/26/2017 at 0:02 PM, earthworm said:

Looks like we're approaching a point where the attractiveness of unRAID is more it's docker, plugin and ease of use over the fact you can plug in all the drives.

 

I'm still a huge fan of the Areca cards mainly for their network port and network management functionality.  I started with the ARC-1170 in a Dell server then moved to the ARC-1261ML.  I have a pair of ARC-1280ML cards I will eventually put into service whenever I get around to it.

 

For the OP, unRAID will work for your purpose.  The disadvantage of running R6 is you must use similar size drives and they must all keep spinning.

 

I don't agree with the first statement - but would go so far as to say that, in earlier versions (pre-unRAID 6), unRAID WAS ONLY attractive to those that wanted to use it to manage a parity protected NAS consisting of disks of various sizes (media server applications mostly). Whereas today, with the vm and docker functionality, users of RAID technology, including non-media server users, are also interested in unRAID. And there is a way for all of us to use unRAID.

 

The parity config that heffe2001 describes is exactly what I have (may have gotten the idea from several of my posts, not sure).

 

The lack of support of Areca drives is due to not being implemented in Dynamix. You'll have to bug @bonienl if you want it added. The thread below should provide all or most of the details needed, and I'd support him if there are issues or questions. BTW, a lot of the credit goes to @bubbaQ who supported me in my efforts to understand how to make this work, I am still running unmenu/myMain. My current version has support and even shows the constituent drives in Areca RAID volumes to pull smart reports at the drive level.

 

There is only 1 thing that Areca cards can't do - spin down a disk. There is a setting to auto-spin down after some period of time in the card's BIOS, that works for my purposes. It must be configured outside of unRAID. This works fine for me as it is rare I manually spindown drives.

 

The other thing I'll mention is that the attractively priced Areca cards are PCIe 1.x spec. PCIe 2.0 drives provide twice the bandwidth. (And PCIe 3.0 cards provide 4x the bandwidth). (See the link below for more explanation of PCIe version and number of lanes have on bandwidth). But you still get 125 MB/sec speeds with 16 drives in a PCIe 1.x slot with 8 lanes (or with 8 drives in a PCIe 1.1 and 4 lanes). That would impact parity check speeds for many on the outer tracks, but I would still call it acceptable for most. Remember all drives driven is a rare situation, normally only affecting parity checks and drive rebuilds. YMMV.

 

When running in RAID mode, the parallel access is even less of an limitation. For example, say you are 5 JBOD drives on the card. Each able to delver 150 MB/sec as near peak. So you'd need the card to handle 750 MB/sec to run all 5 concurrently and not limit bandwidth. But if you were running the 5 as a RAID volume, they would act as a single disk to the OS. And perhaps increase bandwidth by 25% (that's just a guess) over constituent drives' native speed (due to the efficiently of the way RAID works). So, in this example, RAID would need ~190 MB/sec bandwidth for the 5 drives, not 750. 

 

 

Cheers!

Link to comment
On Friday, May 26, 2017 at 9:47 AM, heffe2001 said:

The Areca cards work pretty well with Unraid (I've had no troubles), but aren't 100% supported.  You'll need to check the thread here about how to get it set up, and you won't get accurate drive temp readings, or proper spinup/spindown management from Unraid (but what's built into the card does work).

 

 

No out-of-the-box OS has "complete" support for Areca HW RAID the way you talk about.  You cobble together a build with hardware that uses non-standard interfaces then you have to expect to do some tweaking.

 

If you want to complain, complain to Areca, not OS devs.  And I say this as a long-time (and current) user of Areca HBAs (I have 1882's and 1883's in my servers now).

 

Link to comment

I've not had any real issues with my Areca ARC-1231ML 12 port card.  Like I said, I just wish it had better support (especially with their older cards being so reasonable now.  I really wish the 1680ix 24 port I just got would fit my case, has the external port I need, plus internal (overkill at 24 ports total).  I can certainly live without the OS reading the drive temp or spindowns, but it would be nice, lol.

Link to comment

I hate the long cards with the SFF-8087s on the far end of the card. Bad design.

 

There is no reason that the drives can't report the temperature. Logic just needs to be added to Dynamix. Be a squeaky wheel and maybe it will happen.

 

Sorry about the 1680ix being too long. Sending it back? I bought an LSI SAS9201-16i and a LSI-SAS9201-16e. Good combo for me. The 16i was pricey but the 16e was cheap. Not sure why such a price difference for basically the same card. They are PCIe 2.0 cards. They are not very long and would probably work in most cases.

 

Link to comment

This is such a cool post and great discussion. I love it when you guys start talking about all the different ways you have your systems configured, it always helps me find new ways of doing things. I would have never thought to use a hardware array to "create" a single large parity or cache drive outside of unRAID on my own. In fact, I have often wondered what I would do when I wanted to increase my array capacity as I'm starting off with a 3TB parity size limit. I have just never been able to justify to myself the cost of a larger drive solely for parity sake. Knowing now that I can just slap a few of those 3TB drives together later on is really helpful. That solves that future problem, thanks all!

Edited by ryoko227
Link to comment

I can see where it would become a bit of a bear to manage the hardware level raid and virtual disk presentations for the array storage. I had a spare 8 port card and decided to use it for combining cheap 120GB SSD's for the cache drive. That data is moved off nightly and the persistent data is backed up weekly, so there's not much risk. If a drive dies I simply rebuild the RAID 0 and restore my docker config data. It could be a bit more painful doing that on array/parity disks.

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.