Dell R710 with PERC H310. GPT issues and hardware raid or ZFS?

[Steven Hartland]

----- Original Message ----- 
From: "Jeremy Chadwick" <jdc at koitsu.org>
To: "John" <freebsd at growveg.net>
Cc: <freebsd-fs at freebsd.org>
Sent: Saturday, June 22, 2013 8:16 PM
Subject: Re: Dell R710 with PERC H310. GPT issues and hardware raid or ZFS?


> On Sat, Jun 22, 2013 at 07:19:28PM +0100, John wrote:
>> Hello, thank you for your reply.
>> 
>> On 22/06/2013 18:48, Steven Hartland wrote:
>> > I see you have an dell + mfi controller, there was an important FW update
>> > released a week or so back do ensure you have that installed or you'll
>> > suffer from nasty IO stalls.
>> 
>> Thats... thats what I was seeing!!! I was running a svn update for ports
>> and svn just sat there like a piece of cheese in a state of wdrain
>> according to top.
>> 
>> OK so firstly I need to update the controller. After some googling I
>> found this site https://calomel.org/zfs_raid_speed_capacity.html where
>> they "raid0" each disk to take advantage of the controller, but it seems
>> (so far) with my controller that once hardware raid is enabled it can't
>> be disabled. It does not allow the opportunity to make one raid0 disk
>> from one disk and then go to another disk to do the same. Maybe I should
>> do it with the first one  then let zfs do the remaining three.
> 
> 1. I would recommend you avoid use of the controller entirely.  Get
> yourself a different controller that doesn't do RAID and use that.  If
> you can disable the on-board controller in the BIOS, and pick yourself
> up a Supermicro AOC-USAS2-L8e HBA (around US$140) and use that
> (or even a siis(4) controller (around US$30)), you'd be better off.
> 
> http://www.supermicro.com/products/accessories/addon/AOC-USAS2-L8i.cfm?TYP=E
> 
> This uses the mps(4) driver.
> 
> I'm intentionally keeping this terse rather than going into the
> different HBA types (ex. the 2108 uses mfi(4) (avoid please), and there
> are other models which do RAID but some which can have RAID disabled by
> using a different "version" of firmware (have to ask Technical Support
> for it, etc.).
> 
> 2. The "make each disk a RAID 0 volume" has caveats which the author of
> that article does not disclose.  One of the biggest is if you plan on
> using SSDs with the controller -- you won't be able to get TRIM/UNMAP
> support (via SCSI commands 0x85 (PASS-THROUGH-16) or 0xa1
> (PASS-THROUGH-12) doing that, which will hurt you **big time**.

Some mfi controllers actually have a JBOD option, if it does you'll
be able to this controller if not watch out as using the RAID 0 option
will almost certainly cause you pain.

mps as Jeremy has said is better option.

    Regards
    Steve

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