ServeRAID M5210e passthroughand syspd corruption

[Steven Hartland]

----- Original Message ----- 
From: "Borja Marcos" <borjam at sarenet.es>
To: "Steven Hartland" <killing at multiplay.co.uk>
Cc: <freebsd-scsi at freebsd.org>
Sent: Friday, February 28, 2014 10:32 AM
Subject: Re: ServeRAID M5210e passthroughand syspd corruption



On Feb 28, 2014, at 11:17 AM, Steven Hartland wrote:

> mfi is a raid card it doesn't really have a true passthrough mfisyspd is
> the best you'll get. I'd recommend you switch to an HBA card which uses
> mps driver instead.

> I know, unfortunately this brain dead (unless proven otherwise) IBM
> machine doesn't seem to allow me to use a proper HBA.

Not PCI slots at all then?

> That said, since I asked for assistance in 2007 and Scott Long explained
> how to turn an aac card into a passthrough device I have machines running
> like a charm. I am sure I can trust ZFS to detect any problems due to that
> setup.

Some older LSI controllers (both these are LSI underneath) had both a RAID
and HBA firmware however new cards don't have this option.

> When you said you're seeing mfisyspd corruption what specifically are
> you seeing?

> I described some of the problems several days ago, in short, either using
> ZFS or UFS on one of those "mfisyspd" devices or a "da" created by allowing
> passthrough to work and running a benchmark, I get data corruption. No data
> corruption happens if I create a "raid 0" device on one disk. 

Specifics on this would be interesting, as there used be corruption issues
with > 2TB disks on MFI but we fixed that quite some time ago.

> I've tried with Samsung and OCZ SSDs and, just wondering if it might be a
> SSD specific problem of some sort, a Seagate disk. No luck.

We have a few machines in production here using MFI in passthrough via
mfisyspd0 on ZFS and haven't seen any issues. In our case its a ThunderBolt
not a Invader generation card so if could be there's a problem with
Invader chipset support.

> With so many manufacturers (even Sun!) tending including these controllers
> on their motherboards, and even refusing to sell alternative options (who
> wants a "software RAID" when you can get "a hardware one", they say) I
> think that it would be good to make sure that passthrough mode is supported
> in the best possible way.

We just ensure we go with HBA card if required.

> Maybe we could lobby the LSI Overlords, the manufacturers, both, or just
> try to make the best possible use of the most commonly found hardware.


Can't say we've had an issue, Dell, Supermicro all have options for HBA
you just need to know the model numbers, which can be quite confusing.

One chassis to avoid is the Dell C6220 series as it fails on 6Gbps speeds
due to bad wiring.

    Regards
    Steve

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