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I would like to run freenas on a HP P410 hardware RAID 5 4x600GB 15k SAS array and be alerted in the case of physical disk failure, however the freenas documentation says:

to prevent problems, do not enable the S.M.A.R.T. service if your disks are controlled by a RAID controller as it is the job of the controller to monitor S.M.A.R.T. and mark drives as Predictive Failure when they trip.

As the machine is installed in a lights-out data center, there's no way for the controller to alert anyone of RAID array being degraded. S.M.A.R.T. would appear to be an option - perhaps a physical disk failure would show as a high "Reallocated Sectors Count" at the array level?

Notes: Other options I have considered, but rejected are: Using a dumb HP H220 HBA with RAID-Z (<1.2TB guaranteed) or RAID 10 (1.2TB), but neither provide the capacity of RAID 5 (1.8TB), and I don't have any spare drive bays (HP DL120 G7). Also, there doesn't appear to be an HP agent for BSD. Context: I have a pair of these servers to reconfigure (main and replicated - 8 disks total) and they provide for an SQLServer and other VMs via iSCSI.

Update: I'm going down the cciss route (here's how I installed cciss on FreeNAS 9.x). Other possibility: RAID controller with out-of-band management on ethernet.

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  • The loss in capacity for the non-RAID5 solutions is the price of the increased redundancy. You pays yer money, and you takes yer choice.
    – MadHatter
    Apr 1, 2014 at 10:04
  • Update: I'm considering cciss_vol_status or a RAID controller with out-of-band management.
    – Andy Joiner
    Apr 1, 2014 at 14:33
  • @AndyJoiner Do you absolutely have to use FreeNAS?
    – ewwhite
    Apr 1, 2014 at 15:26
  • There may be resistance to moving away from FreeNAS.
    – Andy Joiner
    Apr 1, 2014 at 15:48

2 Answers 2

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You really can't monitor the array status that well on your platform. One tacky option is cciss_vol_status, but it's far from the mainstream approach.

This is kind of a bad combination of hardware and software. FreeBSD ProLiant support is a bit Meh... Okay, it's actually worse than that...

So a few things to consider:

  • ZFS is a software RAID and volume management solution engineered for use with raw SAS controllers and to bypass any form of hardware RAID.
  • Hardware RAID can be used, but you lose some of the data protection features of ZFS.
  • If you use hardware RAID with ZFS, be sure to do it on an OS/platform that allows you to monitor it!
  • HP Smart Array controllers like the P410 are popular and well-supported under every other operating system out there. They present a block device to the OS comprised of the collection of underlying RAID devices.
  • Smart Array controllers do not have a JBOD or passthrough mode. They are RAID-only.
  • HP has tools and management agents to monitor hardware health and send SNMP and email alerts. Again, these won't work on your FreeNAS.
  • S.M.A.R.T. is not the last word in storage monitoring!

I'd either ditch FreeNAS if you insist on using hardware RAID or use a more ZFS-friendly SAS controller (LSI 9211) or give up the monitoring of the hardware RAID.

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  • +1 for typically excellent ewwhite answer. Why is it that so few RAID cards do JBOD? Is it that doing nothing reliably is very much more difficult than I'd thought?
    – MadHatter
    Apr 1, 2014 at 9:36
  • @MadHatter That's a good question. Today, with Hadoop, Windows Storage Spaces, ZFS, BtrFS, Maxta, VMware vSAN, etc., there is a very high demand for JBOD or passthrough capability in storage controllers. A shame that it's so difficult.
    – ewwhite
    Apr 1, 2014 at 9:47
  • The trouble I had buying a Dell with an H200 in last year, because it supported JBOD and I wanted the server for ZFS. The supplier substituted a Perc 6i (or similar) without telling me, then got all defensive ("but it's a better RAID card, and we gave it to you for free; you'll have to pay express shipping if you want the H200 instead") when I wanted an H200 instead, PDQ.
    – MadHatter
    Apr 1, 2014 at 9:50
  • +1 for cciss_vol_status. Though I could never "give up the monitoring of the hardware RAID". ZFS just doesn't give me the capacity (I could loose >30% space to RAID-Z skipped blocks and single-block writes).
    – Andy Joiner
    Apr 1, 2014 at 10:06
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    @andy Larger disks are an option, no? 3.5" has 600GB 15k SAS maximum, but you have larger nearline 7.2k disks available. Do you have any option to use a more suitable server for this (>4 drive bays, etc)?
    – ewwhite
    Apr 1, 2014 at 10:12
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The way you would normally monitor this is with the HP software and agents.

Unless you can install this software on FreeNAS you may be out of luck. This ultimately falls down to the hardware not being fully supported for various reasons (not important in this discussion)

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  • -1 Sorry, but your Answer seems to blame FreeNAS (based on FreeBSD) for not supporting HP's proprietary, closed-source, copyrighted, and otherwise protected intellectual property. The FreeBSD community has been trying to get HP to cooperate for years - HP has chosen not to work with the community. If you want to mention that HP tightly controls the OSes they choose to support I'd be happy to remove my downvote, but blaming FreeNAS is ignorant.
    – Chris S
    Apr 1, 2014 at 15:47
  • @chriss any idea why HP doesn't have basic BSD support? It's unacceptable, given that Netware and Solaris even have driver/utility support.
    – ewwhite
    Apr 1, 2014 at 17:36
  • @ewwhite The discussion almost invariably goes like this: "Hey MegaCorp, can we get a driver, or the spec, for your hardware so we can support it?"; they respond "Your OS isn't a large enough market for us to support it. There are too many 'risks' involved with releasing the source/spec/whatever." Enough community pestering usually gets some half-effort binary blob that breaks far too easily to be supportable... And on rare occasions they realize there's no secrets to their hardware anyway and you end up will wonderfully supported devices (like LSI, Adaptect, AMD [not their GPUs though])
    – Chris S
    Apr 1, 2014 at 17:42
  • I'm not blaming anyone. I'll reword my answer to say 'not supported on FreeNAS' rather than saying 'FreeNAS not supporting...' if you would prefer.
    – Snellgrove
    Apr 2, 2014 at 20:56

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