Date: Wed, 19 Nov 2008 11:48:53 -0800 From: Jeremy Chadwick <koitsu@FreeBSD.org> To: John Almberg <jalmberg@identry.com> Cc: freebsd-questions@freebsd.org Subject: Re: snmpd strangeness Message-ID: <20081119194853.GA5901@icarus.home.lan> In-Reply-To: <E75530E4-DD9E-4002-B7D0-BBF98EF02208@identry.com> References: <BFDB04F6-6032-4CBE-859A-CB2BEE3A4C4E@identry.com> <20081119164919.GA2347@icarus.home.lan> <EFB2D630-CDB6-4E5C-98BF-5A37A3502D71@identry.com> <20081119172649.GA3139@icarus.home.lan> <A0526D15-3EF3-40E3-9362-F80DE5FF364C@identry.com> <20081119185829.GA4786@icarus.home.lan> <E75530E4-DD9E-4002-B7D0-BBF98EF02208@identry.com>
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On Wed, Nov 19, 2008 at 02:37:05PM -0500, John Almberg wrote: >>> This machine has an Intel motherboard and a hardware raid controller. >>> From what I can tell, there is some Intel software installed on the >>> machine that makes hardware faults visible to snmp. >> >> That would require Net-SNMP to be linked to that software (or library) >> directly. Two things can't just "magically talk" to one another. :-) > > As I said, I really have no idea. > > Now that I'm reading more deeply in the notes... the monitoring was > supposed to be with IPMI. No idea what that is, either, but I thought > I'd toss it into the mix. Ah, IPMI... it's another one of those technologies which is a great idea, but often horribly implemented. The most common use is for remote management (serial-over-IP, or even KVM-over-IP), access to hardware sensors (fans, temps, voltages), and for some other monitoring-related things. It's very useful -- when it works. :-) On Intel boards (native Intel IPMI) it might be great. There's been a lot of problem reports with Supermicro's IPMI, and most are IPMI card firmware bugs. >> I just hope the card is an actual RAID card and not BIOS-level RAID >> like >> Intel MatrixRAID. If it is MatrixRAID, I highly recommend you back >> the >> entire machine up and reinstall without MatrixRAID, otherwise when you >> lose a disk or need to rebuild your array, you'll find your array >> broken/gone, be completely unable to rebuild it, or kernel panics. >> Note >> that all of this stuff works just fine on Linux; the issues listed are >> with FreeBSD. >> >> Generally speaking, we (the open-source world) have gotten to the >> point >> with OS-based software RAID (e.g. Linux LVM, FreeBSD ccd/gvinum/ZFS, >> OpenSolaris ZFS) where it offers significant advantages over hardware >> RAID. There are good reasons to use hardware RAID, but in those >> scenarios admins should be looking at buying an actual filer, e.g. >> Network Appliance. Otherwise, for "simple" systems (even stuff like >> 2U or 3U boxes with many disks, e.g. a "low-cost filer"), stick with >> some form of OS-based software RAID if possible. >> > > That's good to know. I was told just the opposite by the guy selling the > $650 RAID cards. Who'd have thunk? Well, hardware RAID has a specific purpose. I like them for the fact that they add a layer of abstraction in front of the OS; that is to say, some of them are bootable even with RAID-5. FreeBSD's bootloader has a lot of difficulty booting off of different things, so adding a layer of abstraction in front is useful. For example, take into consideration that you can't get kernel panic dumps (to disk) using gmirror without a bunch of rigmarole. I forget which GEOM method it is, but one of them you can't boot off of easily. gvinum? geli? I can't remember. There's one or two that the bootstraps don't work with. Hardware RAID can help solve that. > The card in the box is a > > Intel 18E PCI-Express x8 SAS/SATA2 Hardware ROMB RAID with 128MB Memory > Module and 72 Hour Battery Backup Cache > > $625 as shown on the packing list, so I hope it's a good one. Ah, I think it's hardware RAID, and PCIe to boot. Yes, I would recommend keeping that! What does it show up as under FreeBSD? I'm curious what driver it uses, and what your disks show up as (daX or adX; probably daX). -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |
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