Susan Scheufele wrote:
> Hi Garrett,
>
> Garrett D'Amore wrote:
>> I'd like some clarifications:
>>
>> Dos this driver support a set of hardware that is distinct from that
>> supported by megasas? I.e. no overlap between what drivers requiring
>> users to "choose" which driver to use for their hardware, right?
>
> You are correct, the mr_sas driver supports a set of hardware that is
> distinct from what is supported by the mega_sas driver. This "gen2"
> driver supports SAS2.0 hardware (as well as SAS1.0 hardware). There is
> no overlap between the drivers, and users will not "choose" which
> driver to use for their hardware.
>
>> I seem to understand that this driver *only* supports drives
>> configured as a RAID, and doesn't support ordinary JBOD uses?
>
> This is true. All disks supported by the mr_sas driver will be RAID
> volumes, even if only RAID 0 or RAID 1.
>
>> So a drive used with this controller can only be used with either
>> megasas or another instance of this driver. Right?
>
> LSI will support migrating MegaRAID drives from the gen1 cards/driver
> to the gen2 cards/driver, and vice versa.
Understood. The key take away is that these drives are not compatible
with "ordinary" SAS controllers from other vendors. (Or rather, any
drive content cannot be preserved across such a move.)
I'll give this proposal +1, with a gentle "wishlist" item to have the
ability to use the drives as JBOD (e.g. for use with ZFS, or because
drive portability is important to the user).
-- Garrett
>
> -Susan
>
>> -- Garrett
>>
>> Frank Che wrote:
>>> I'm sponsoring this fast track for Susan Scheufele and Yu Wu.
>>> Requested release binding is Patch. Timer is set to Mar 12, 2009.
>>>
>>> -Frank
>>>
>>> 2. Project Summary
>>>
>>> This project integrates LSI MegaRAID SAS2.0 Controller HBA driver,
>>> mr_sas, into Solaris. Requested Release binding is Patch.
>>>
>>> LSI's next generation of SAS2.0 HBA controllers will support a new
>>> driver based on the LSI's MegaRAID Firmware Interface (MFI).
>>> The driver was developed by LSI, and the driver capabilities are
>>> significantly upgraded from the previous generation driver, including
>>> dynamic enumeration, SMP support, Hot Plug for Disk and HBA, tape
>>> pass through, and a related kmdb module. The new driver supports
>>> the LSI SAS2108(Liberator) controller.
>>>
>>> 4. Technical Description:
>>>
>>> 4.1. Details:
>>>
>>> The mr_sas(7d) driver will support LSI's MegaRAID SAS2.0
>>> controllers, and will not support LSI's SAS1.0 controllers.
>>> The on-disk metadata format is compatible, so that MegaRAID
>>> drives can be moved from SAS1.0 to SAS2.0 controllers without
>>> fear of data loss, and vice versa.
>>>
>>> The mr_sas(7d) driver will be DDI and SCSAv2-complaint, as
>>> much as possible. The driver will provide new functionality compared
>>> to the existing megasas(7d) driver: dynamic enumeration, SMP,
>>> drive hot plug, and a related kmdb module. Additional software
>>> features are planned to be implemented by LSI and Sun in separate
>>> phases over the next year.
>>>
>>> 4.3. In Scope:
>>>
>>> The following features are supported in the initial version
>>> of the driver.
>>> X86 Support - starting with X86 due to limited hardware
>>> availability
>>> Sparc Support - available within 2 builds of the X86 support
>>> 64 bit DMA - normal HBA feature, was missing from gen1 driver
>>> initially
>>> Dynamic Enumeration - .conf file not required to attach logical
>>> drives
>>> SMP Enumeration - logical drives may be accessed via a SAS
>>> expander
>>> FMA level 2 support - checks for errors on DMA and PIO accesses
>>> Hot Plug of Drives - handled via the LSI management utilities
>>> MSI-X support - for MSI and MSI-X interrupts.
>>> Solaris quiesce - for fastboot support
>>> mdb walker - provides driver-related kmdb info
>>> Expander pass through - for specified SAS expanders
>>>
>>> 4.4. Out of Scope:
>>>
>>> The following features are planned as follow-on enhancements for
>>> the driver. They are not supported in the initial release
>>> of the driver due to time-to-market considerations.
>>> Tape pass through - for specified SAS tape drives
>>> Hot Plug of HBA - first RFE following Sparc, required for blades
>>> SMP Multipathing - requirements need further clarification,
>>> for load balancing and failover
>>> Power Management - LSI is investigating the fw support required
>>> Timeout support - LSI is investigating the fw support required
>>> PCI-E relaxed ordering - verified that the device supports it
>>> kstats - part of follow-on performance work
>>> kmem_cache_alloc - if performance testing warrants its usage
>>> fwflash plugin - firmware upgrade for the card and drives is
>>> already
>>> handled via the LSI management utilities
>>> FMA 2.5 support - support for LSI MegaRAID-specific error
>>> conditions,
>>> is already handled via the LSI management utilities
>>>
>>> The following features are not supported with mr_sas(7D):
>>> raidctl plugin - Sun has made a business choice to pass through
>>> the responsibility for the device configuration tools to the
>>> vendor (eg, LSI). There is no "value add" in adding the same
>>> capabilities that LSI provides today.
>>> MPXIO - generically does not work with RAID drivers
>>> JBOD passthrough - no near-term support for this feature is
>>> planned
>>> iPort code - only applies if there is JBOD passthrough support
>>> WWN registration of devices - no support for this feature is
>>> planned by LSI for this driver
>>>
>>> 4.5. Interfaces:
>>>
>>> The project exports the following interfaces:
>>>
>>> Interface Name Stability Comments
>>> --------------- --------------- -------------
>>> mr_sas(7D) Committed Driver name
>>> SUNWmrsas Committed Package name
>>>
>>>
>>> 4.6. Doc Impact:
>>>
>>> A man page will be created for the mr_sas(7d) driver.
>>>
>>> 4.7. Admin/Config Impact:
>>>
>>> The BIOS will be used to create RAID volumes for X86 platforms.
>>> There is a minimal Fcode interface that may be used to create
>>> RAID volumes for Sparc platforms. In addition, LSI's RAID
>>> configuration and management utilities are supported with this
>>> driver, and are available for download from LSI's website.
>>>
>>> 4.8. HA Impact:
>>>
>>> Not supported due to lack of MPXIO, which generically does not
>>> work with hardware RAID drivers.
>>>
>>> 4.10. Packaging & Delivery:
>>>
>>> The mr_sas(7d) driver will be delivered initially on the x86
>>> architectures, and shortly thereafter on Sparc. The mr_sas(7d)
>>> driver will be included as:
>>>
>>> /kernel/drv/mr_sas
>>> /kernel/drv/mr_sas.conf
>>> /kernel/drv/amd64/mr_sas
>>> /kernel/drv/sparcv9/mr_sas
>>>
>>> The mr_sas(7d) manpage will be included in SUNWman.
>>>
>>> 6. Resources and Schedule:
>>>
>>> 6.4. Product Approval Committee requested information:
>>> 6.4.1. Consolidation or Component Name: ON
>>>
>>> 6.5. ARC review type: Fast Track
>>>
>>> 6.6. ARC Exposure: open
>>>
>>>
>>
>
