SuperMicro 5015A-EHF-D525 = To RAID or Not to RAID, that is the question.

  • I purchased a couple of Supermicro 5015A-EHF-D525 Atom servers for a client with the intention of doing RAID1 Mirror to reduce downtime on the chance of a Hard Drive Failure.

    One box will be used for an Asterisk installation, the second box for a pfSense installation. This being my first 2.0 installation into production, I'm questioning the decisions on choice of hardware and the latest version of pFSense regarding RAID 1/.

    Essentially, I'm confused. Likely induced from my experience/troubles installing the first Asterisk box (new hard drive block errors ended up sending the RAID setup for a loop.. fixed it now).

    This Atom server has what is referred to as "Fake Raid" and what some seem to call "Software Raid". I question the term Software Raid since it does have a BIOS implementation, and the software RAID I would usually suggest is strictly done on the OS side. The BIOS has two RAID options… Intel or Adaptec... I've chosen Adaptec (no real reason other than Intel seems to only support Windows mostly and Adaptec "appears" to support in BIOS rebuilds, is this true?).

    My confusion is this... what is easier to recover from in the case of someone coming into the situation off the street (say a new admin) and trying to replace a failed hard drive. The adaptec RAID functions in the BIOS (Ctrl-A) seems to have the ability to Create Arrays, Add HotSpares, etc... but most importantly, it seem to have the ability to choose to "Rebuild"... If you choose "Crtl-R" to rebuild, it appears to show a progress of the rebuild (in %), I have not actually tried this yet. But it was similar in fashion when setting up the original Array... progress shown in %. If I recall, the original concerns of the Fake RAID systems was that it required the user to boot into an OS that supported the RAID (which seems to be 100% Windows for Intel RAID, and questionable (in terms of simplicity) for Adaptec RAID for Linux / BSD). Again, the reason to avoid these systems I thought was because you could NOT rebuild without booting into a supported OS. Can someone clarify that this board allows rebuilding without this?

    When I built the Asterisk box, I also found out that throwing a mirror drive into another machine that did not have the adaptec fake RAID, resulted in a failed boot up (on drivers). What I really did was just disable the Adaptec FakeRAID on the same box (much like say a Battery failure/replacement or Default BIOS Settings... So apparently, if a motherboard failed, you could not just swap  out the drives... the OS wants the adaptec FakeRAID.

    In my mind, the adaptec BIOS is the easiest way to replace a failed drive. But it seems to still be shot down in the articles I've read from a few years back. I see many articles saying use Software RAID (created by the OS... in Linux and BSD). What am I missing?

    Specifically back to pfSense, I can't see much of anything in articles indicating that I should just install pfSense onto the array I defined in the Adaptec BIOS options... (of course it will work, but should I??).

    Now, with pfSense 2.0's new installation options, I notice the GEOM Mirror, which when I try to read up on it, it seems to be true software (OS based) RAID.... Is Adaptec FakeRAID also supported? Or do I just setup the drives as simple, non-RAID hard drives and go through that setup? Is the "Setup GEOM Mirror" basically the OS setting up the Mirror? Hardware independant? I have setup a test of this without FakeRAID enabled... but I am trying to see what admin tools are built into pfSense to monitor the RAID and report on issues/failures? Does this exist?

    ??? ???

    Any help or suggestions would be greatly appreciated.


  • Rebel Alliance Developer Netgate

    I'd just use the drives directly and then do a custom install, choosing gmirror, and let pfSense/FreeBSD handle the RAID. There is a widget to monitor the status of a gmirror array as well.

  • Thanks… I think that is the best way.

    The widget you speak of, is this just part of the packages in pfSense? Or is this something else? What is it called?

  • Rebel Alliance Developer Netgate

    It's in 2.0 by default, just called "gmirror status"

  • Great, thanks… I am using that.
    Is there anything that actually monitors and alerts on failure? HDD failed, it emails an admin? The widget I assume only allows you to look at the status.

  • Rebel Alliance Developer Netgate

    No, there is no alerting mechanism for that.

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