Date: Fri, 23 Jan 2015 13:41:25 +0200 From: Ahmed Kamal <email.ahmedkamal@googlemail.com> To: David Gwynne <david@gwynne.id.au> Cc: freebsd-scsi@freebsd.org Subject: Re: Dell branded storage controller for ZFS file-server | Advice requested Message-ID: <CANzjMX4eyuPJ1qFvye6ECHDbJq8OZdoE7F2PzpaAFiME06fX5A@mail.gmail.com> In-Reply-To: <EDB1FFA8-5311-4846-BCFF-127DF9A71453@gwynne.id.au> References: <CANzjMX4GXf_jMMKZVSE3kf4NCvOUR0anjda3KSvFTNn6-%2BWmGg@mail.gmail.com> <EDB1FFA8-5311-4846-BCFF-127DF9A71453@gwynne.id.au>
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Thanks a lot for your reply .. I've got a couple of questions inline On Fri, Jan 23, 2015 at 12:21 PM, David Gwynne <david@gwynne.id.au> wrote: > > > On 23 Jan 2015, at 7:16 pm, Ahmed Kamal <email.ahmedkamal@googlemail.com> > wrote: > > > > Hi everyone, > > > > I'm looking to build a ZFS file-server, unfortunately I'm locked into > Dell > > branded hardware only. I know Dell sometimes ships LSI branded cards, but > > that too probably won't work for me, as I live outside the US and the > local > > Dell rep is clueless (so whatever I want to buy, has to be on Dell's > > website). I am considering Dell R720xd or R730xd. I will use Intel i350 > > NICs, and ECC RAM, but the biggest questions are around the SAS HBA > > > > Per my research, I have the following notes and questions. Appreciating > > your comments on them > > > > * H310 Card supports syspd (jbod) mode per > > http://svnweb.freebsd.org/base?view=revision&revision=254906 so it is > > probably the best card for what I want to do, right? > > no. > > > * H310 is a low end card, it has very limited queue depth (25 I believe) > .. > > Is this actually a problem when using the disks (20 x SAS 10k disks) in > > syspd/jbod mode? what about if I attach a couple of SSD disks? > > there are two queue limits here, one for the controller and one for each > disk attached to it. > > h310s have a controller queue depth of 31, ie, they can only support 31 > commands at a time. if you have 24 disks and distribute the controllers > command slots between them, thats about 1 command per disk. > My initial line of thought was that in pass-through (jbod) mode, the HBA does *not* buffer commands and proxy disk responses internally. Which meant that in jbod mode, the HBA basically becomes a communications channel connecting the OS to disks, making its internal buffering limitations not-applicable. Is this not correct ? > > > * H310 can be flashed to IT mode (LSI firmware), and is supported by > > Illumos kernel (if I'll ever need that) .. so overall it looks like a > good > > option. Any "watch-outs" I should be aware of ? > > yes. if you flash the h310 to become an sas hba, the pci product/vendor > and subproduct/subvendor ids on the controller change. the dell bios will > refuse to boot if it detects an unsupported controller in its storage slot. > you'll brick the machine until you remove the h310. because it is on a non > standard mezzanine connector you will not be able to flash it back to a > h310, and you'll have a useless chunk of silicon to put on your desk as a > monument to how annoying vendors are. > pff nightmare scenario .. thanks for pointing this out. I stumbled across web posts where people successfully flashed h310, but meh, now I'm scared to buy that configuration > > > * H710/p have no way of exposing JBOD/syspd in any way .. If using those > > cards, the best I can do, is to create a raid-0 per disk, and put zfs on > > top of that. How bad is this? Is the only problem that I'm locked into > H710 > > firmware? Would the nvram and bbu on H710 improve performance > significantly > > vs H310? > > i wouldnt run zfs on that. > > > * H330 and H730, seem supported by mrsas driver. Is this driver able to > > expose jbod/syspd mode? If yes, what's the overall advise, should I go > with > > one of those, or the "trusty" H310 ? > > thats a workable option. h330 should be fine if all you want to do is jbod. > Now that you're pointing me to H330 being my best option given the situation, got some more questions: * "if all you want is jbod" .. with zfs, that's all we need right ? just wondering if I'm missing something important * Any idea if jbod configuration on h330 is done on bios level, or using some freebsd tool (how?) * mrsas man page, mentions the driver appeared in 10.1 .. Does that mean if I decide to use FreeNAS (9.x based) it won't be there ? * If I go the h330 path, it'll be a r730xd server. Worst case if the h330 gives me trouble, can I throw it out and plug a LSI 9207-8i in its place (same pci slot, cables ..etc) ? Thanks! > > > > > Your help and advice is most appreciated > > _______________________________________________ > > freebsd-scsi@freebsd.org mailing list > > http://lists.freebsd.org/mailman/listinfo/freebsd-scsi > > To unsubscribe, send any mail to "freebsd-scsi-unsubscribe@freebsd.org" > >
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