LSI - MR-Fusion controller driver <mrsas> patch and man page

[Doug Ambrisko]

Quick question, what version of FreeBSD are you using?  I netbooted
current and then did:
	newfs /dev/da4
	mount /dev/da4 /mnt
	cd /mnt ; bonnie++ -u 0
da4 is a Toshiba 300G SAS drive.  This worked okay.

Thanks,

Doug A.

On Tue, Mar 25, 2014 at 09:12:09AM +0100, Borja Marcos wrote:
| 
| On Mar 24, 2014, at 6:45 PM, Doug Ambrisko wrote:
| 
| > On Mon, Mar 24, 2014 at 09:03:43AM +0100, Borja Marcos wrote:
| > | 
| > | On Mar 21, 2014, at 5:09 PM, Doug Ambrisko wrote:
| > | 
| > | > Do you have a simple test case for that?  There were issues in the SCSI
| > | > command translation which should have been fixed via switching it to use
| > | > the CAM translation code.  Can you try it via a RAID volume of one disk?
| > | 
| > | Yes, I tried all those possibilities. "syspd" devices, passthrough 
| > | (same result, corrruption) and when creating single-disk RAID0 volumes 
| > | it worked, no corruption.
| > 
| > Okay, so you don't have and simple test case to show this.  What are
| > you currently doing?  I would think the syspd and the single disk RAID0
| > should be very similar.  I'll take a look at that.
| 
| Yes, sorry for not being so explicit.
| 
| The server  I tried has a backplane, with 23 disks fitted. At first  
| I assumed it would work, so I just created a raidz2 vdev  and begun running benchmarks. That's where I noticed  that it was
| corrupting data badly.
| 
| The disks were set as "JBOD" with the Invader's built-in configuration tool and visible as mfisyspd drives.
| 
| So I reduced it to using a single disk. Choosing one of them at random, I did a newfs. Mounted, and executed
| bonnie++. I got a panic after  some time. To avoid the inconvenience of panics, I moved to ZFS (single disk vdev) 
| so that I could still detect corruption.
| 
| The tests I did were:
| 
| - Disk in JBOD/syspd mode, accessed through /dev/mfisyspd -> corruption
| - Disk in JBOD/syspd mode, passthrough enabled, accessed as /dev/daX -> corruption
| - 1 disk RAID0 volume, accessed as /dev/mfid0 -> NO corruption
| 
| And I understand that syspd and RAID0 should be really different. I understand that it's a shallow layer
| doing little more than passing through commands? I should read the driver thoroughly it seems... Pity there
| are no available documents.
| 
| > | Just in case I tried with SSDs (Samsung EVO  840 and OCZ Vertex 4) and 
| > | Seagate SAS disks.
| > 
| > So it seems generic.  Size of disk might be useful.
| 
| 
| The Samsung are 1 TB, the OCZ are the 512 MB ones, and the Seagates are 146 GB. 
| The SSDs (Samsung and OCZ) are SATA disks, the Seagate is SAS. The Seagate was corrupted as well in the
| same test cases, so it doesn't seem to be linked to SATA-on-SAS or to TRIM. TRIM, anyway, doesn't work
| on "mfisyspd" devices, which is a problem if you want to run ZFS on SSD disks.
| 
| > | Actually I think that converting passthrough disks to "mfisyspd" or an
| > | equivalent is a bad idea, unless, of course, there's a compelling reason
| > | I don't realize. For instance, if you are using SSDs you need access to
| > | the TRIM command.
| > | 
| > | So, if I can vote, I vote with arms and legs for "da" devices in case it's
| > | a passthough.
| > 
| > Nothing is planned to be removed from mfi.  However, LSI would like mrsas
| > to be used on newer cards.  We've let people LSI know that people use
| > the pass through mode and having the logical volumes come up as /dev/daX
| > and pass through would be confusing.  Granted mrsas doesn't support pass
| > through so that isn't a problem.
| 
| Pass through is a critical feature when you are running ZFS. I think it's a real problem
| if the new driver (the only one that will support newer cards, I guess) won't support
| pass-through. 
| 
| And of course I know that you can just buy making sure that you get HBAs instead of
| RAID cards, but  so many manufacturers bundle those RAID controllers in fixed  configurations
| that it wouldn't be practical.
| 
| The ideal solution would be to have logical volumes come up as /dev/mfid, /dev/mrsas, /dev/mfisyspd
| or whatever, and passthrough devices as real passthrough devices like /dev/da. That would avoid
| confusion.
| 
| So, please, LSI, consider it. It would really add to the versatility of your cards and there's nothing
| to lose.
| 
| > | It's not a pressing need, I installed a LSI2008 card and I connected the 
| > | SAS backplane to it, so for now the Invader
| > | is a non-problem, but if it will help to run some tests with the mps 
| > | driver I can certainly do it.
| > 
| > The mps driver is a different thing, mrsas is LSI's replacement for mfi
| > with newer cards.  So if you could try syspd and single RAID 0 test
| > with mrsas that would be great to see if that shows the same pattern
| > of syspd failing with mfi and passing with single RAID 0.  Again,
| > the logical volumes will show up as /dev/da* with no pass through
| > devices.  If I can reproduce the problem then I can look into here
| > or others might be able to find the solution.
| 
| I'll try, thanks :)
| 
| 
| 
| 
| 
| Borja.
| 
|