Hi,

 

Is there a possibility to configure Unraid for more than 12 disks?

 

As of now, I have 3  5in3 modules with 9 drives. Theoretically, stacker can support upto 20 drives (with 4 5in3 modules, of course with huge dual power supplies!). Thinking of heating concerns, if not 20 drives.. at least 16 drives would be feasible with 4 4in3 modules.

 

Is there a way to change some parameters to configure Unraid's maximum support of drives? and has Tom (or anyone else) every tried this out?

 

Also, does anyone else have used these 5in3 modules at full capacity (filled with 5 drives). I was concerned about the heating issue. Currently I have configured like (DEDED  DEDED  DEDED) where D= drive, E= empty slot. If someone else is using these modules filled with pretty large drives like 300/500GB's, I'll feel more comfortable putting more drives in.

 

 

Thanks

You may have to search a few threads, but Tom has said in the past that the current unRaid driver module can support a total of 16 drives (parity + 15 others)

 

But...

 

I've never heard of anybody setting up that many disks, and it would basically be editing the "go" script.  The odds are high the management page will not function with more than 12 disks because it seems to show 12 disks only. 

 

So, even if you could configure the array, the odds are you would not be able to manage the array with the software Tom provided.  Who knows... perhaps it shows the number configured and dynamically adjusts.  You will need to ask Tom... (good luck, you are pretty much on unexplored territory)

 

Joe L.

Joe,

 

I would disagree (without first hand knowledge mind you) that the management page would not show more than 12 disks.  I base this only on what I have expermented with and what I have seen.  If you set the "Model=" parameter in the model.cfg file to MD800 the management page shows only 8 total disks.  I would also guess (again a guess) if you set the "Model=" to custom and then went and commented out lines in the "custom" section of the go script I would bet you could get the management page to show any number of drives you would like to see.  More than 12, who really knows and yes you're right there may be driver issues in play here as well but if Tom once said 15 I would think.....!  If I had a spare promise card I would give it a try....!

 

 

Joe,

 

I would disagree (without first hand knowledge mind you) that the management page would not show more than 12 disks.  I base this only on what I have experimented with and what I have seen.  If you set the "Model=" parameter in the model.cfg file to MD800 the management page shows only 8 total disks.  I would also guess (again a guess) if you set the "Model=" to custom and then went and commented out lines in the "custom" section of the go script I would bet you could get the management page to show any number of drives you would like to see.  More than 12, who really knows and yes you're right there may be driver issues in play here as well but if Tom once said 15 I would think.....!  If I had a spare promise card I would give it a try....!

It would be great if that was true, and the management page was entirely dynamic.  It would make sense to code it in that fashion.

 

On the other hand, Tom has repeatedly said that the Promise BIOS under Linux will only support two cards, so you would need to find a different brand if you wanted to experiment, or use SATA for the continued expansion as you are already maxed out. I don't think the brand matters as long as it is recognized by the Linux kernel, and I would expect most IDE controllers to be recognized these days.

 

Sinice Tom has not done much work (if any) with array sizes larger than 12, who knows what you will find.  I do know that reconstruction of data from a missing drive will take even longer since 15 drives will need to be read to reconstruct the missing one.

 

To me, as disks get bigger, a few 750Gig drives will allow expansion without all the other bother.

 

Joe L.

I said that I remembered Tom stating that the unRaid software could handle 16 disks, and I found the post on AVS where he made that statement.

 

It is here: http://www.avsforum.com/avs-vb/showthread.php?p=7432209&post7432209

 

However... I found the following in the source code for the unRaid driver he included with the 324 release.

/* The maximum number of disks per array that we support. */
#define MD_SB_DISKS     12

Now, it might be that the management software can handle more than 12 disks, but the source code he included for the unRaid driver shows that it was configured for 12 disks, not 16.  Granted, this is only a defined constant, but it probably is how he last compiled the unRaid driver. 

 

From my limited understanding of the source code, this might not include the parity drive, so we might be able to get 12 data drives without re-compiling... you are on your own here... good luck experimenting

 

Edit: looked closer and it seems the parity drive is included in the above number, so it looks like a max of 12 (11 data + parity) for now unless you recompile the unRaid module.

 

As I said earlier, if you do try to build an array with more than 12 disks you might run into issues Tom never experienced.

 

Joe L.

Originally had support for 16 drives, but to get there you have to mix controllers, e.g., 2 Promise + 1 SIIG, or 2 Ultra100's + 1 Ultra133.  Anyway, I thought it would be a support nightmare - having enough trouble with support now 

Hi Tom,

 

I can understand your support issue w/ mixed controllers. But does it mean that if I use just 2 Promise controllers (two PromiseSX8 models totalling 16 drives --OR-- one SX8 and one TX4 and 4 on mobo --OR-- two TX4s and 8 on mobo...) should things work? As in this case, it won't require any support issue related to mix controllers... and will the management page will work too...

 

Thanks

bump...

Hi Tom,

 

I can understand your support issue w/ mixed controllers. But does it mean that if I use just 2 Promise controllers (two PromiseSX8 models totalling 16 drives --OR-- one SX8 and one TX4 and 4 on mobo --OR-- two TX4s and 8 on mobo...) should things work? As in this case, it won't require any support issue related to mix controllers... and will the management page will work too...

 

Thanks

 

There are two distinct issues with what you are asking:

 

1. 16-drive support: in the software there is a "constant" that defines the maximum number of drives to be 12.  This can be set to 16 but there might be some consequences.  At one point we did have it at 16, but during a period of development where we were trying to reduce memory usage, it was set down to 12 (since that was the max product configuration).  It's an easy thing to set back to 16 and recompile, however, extensive testing would be required to ensure there are no memory issues.  This is even more vital since there is no swap space.

 

2. Mixing controllers: Having an SX8 and a TX4 would be considered "mixing controllers".  The issue here is not so much that controllers are mixed, but that we don't have an SX8 in house and I don't know how linux will end up assigning devices to it.

 

Nevertheless, I will say this: IF you are experienced with the linux environment, tools, etc., AND you don't mind an interative development process, then send me an email and perhaps we can get this config to work.