# Using MRSAS driver during 10.3 install



## drobison (Jul 5, 2016)

Hiya,

Trying to install a system with FreeBSD 10.3-R AMD64 UEFI DVD. This system needs the MRSAS driver, so I follow the instructions found here:

https://forums.freebsd.org/threads/54222/

However, when I drop to the loader prompt and try to :


```
set hw.mfi.mrsas_enable="1"
```

I have to use the shift key for the underscore and quotes. Every time I hit the shift key it acts sort of like the tab key and inserts a bunch of blank spaces. The command always complains "wrong number of arguments".

I've tried this through a KVM and through a USB keyboard attached to the front panel with the same result.

Ideas?


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## windscape (Jul 5, 2016)

If the system supports booting from a USB flash drive, you could instead use the memstick image and modify /boot/loader.conf to contain that line prior to booting the system from the USB flash drive.


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## drobison (Jul 5, 2016)

windscape said:


> If the system supports booting from a USB flash drive, you could instead use the memstick image and modify /boot/loader.conf to contain that line prior to booting the system from the USB flash drive.



Good thinking, thanks!


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## drobison (Jul 6, 2016)

windscape said:


> If the system supports booting from a USB flash drive, you could instead use the memstick image and modify /boot/loader.conf to contain that line prior to booting the system from the USB flash drive.



This works fairly well. Have to remember to drop to the shell after the install but before first reboot and put the applicable sysctl line into /boot/loader.conf, otherwise my system will never boot. First it drops to the mountroot prompt where I have to specify an mfid0 boot partition, then when it tries to mount dev it goes into endless timeouts.

As I understand it, mrsas is the newer replacement for the mfid driver. I may be wrong about this, but it seems to me that mrsas should be the default during the install.


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## SirDice (Jul 8, 2016)

drobison said:


> As I understand it, mrsas is the newer replacement for the mfid driver. I may be wrong about this, but it seems to me that mrsas should be the default during the install.


No, this would cause problems with older cards that are not supported by mrsas(4). Most cards are supported by mfi(4). Some are support by both mfi(4) and mrsas(4). And some are only supported by mrsas(4). But the majority is covered by mfi(4).


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## drobison (Jul 8, 2016)

SirDice said:


> No, this would cause problems with older cards that are not supported by mrsas(4). Most cards are supported by mfi(4). Some are support by both mfi(4) and mrsas(4). And some are only supported by mrsas(4). But the majority is covered by mfi(4).



Well, anyone with newer hardware won't be able to install properly which is going to cause a lot of problems as well.


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## kpa (Jul 8, 2016)

Ideally none of these drivers would be in the GENERIC kernel and you could just load everything as loadable modules but that would be very slow on boot if everything was loaded as modules and our loader(8) doesn't have any means for detecting hardware. The inclusion of one driver over another in the GENERIC kernel is a matter of convenience for the user doing a fresh install, make that process too hard by for example requiring them to load kernel modules manually and they won't install FreeBSD.


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## Terry_Kennedy (Jul 10, 2016)

kpa said:


> The inclusion of one driver over another in the GENERIC kernel is a matter of convenience for the user doing a fresh install, make that process too hard by for example requiring them to load kernel modules manually and they won't install FreeBSD.


I seem to remember that some RAID driver (maybe hptrr(4)?) had a loader tunable to enable / disable it attaching to cards, since at least some of the cards had the same PCI ID as the "dumb" (non-RAID) version. Perhaps something similar could be done to control mfi(4) vs. mrsas(4) driver attach?


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## SirDice (Jul 12, 2016)

Terry_Kennedy said:


> I seem to remember that some RAID driver (maybe hptrr(4)?) had a loader tunable to enable / disable it attaching to cards, since at least some of the cards had the same PCI ID as the "dumb" (non-RAID) version. Perhaps something similar could be done to control mfi(4) vs. mrsas(4) driver attach?


Yes, that's exactly what hw.mfi.mrsas_enable does.


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