From owner-freebsd-stable Thu Oct 29 13:35:13 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id NAA25725 for freebsd-stable-outgoing; Thu, 29 Oct 1998 13:35:13 -0800 (PST) (envelope-from owner-freebsd-stable@FreeBSD.ORG) Received: from pop.uniserve.com (pop.uniserve.com [204.244.156.3]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id NAA25719 for ; Thu, 29 Oct 1998 13:35:10 -0800 (PST) (envelope-from tom@uniserve.com) Received: from shell.uniserve.ca [204.244.186.218] by pop.uniserve.com with smtp (Exim 1.82 #4) id 0zYzii-0002OA-00; Thu, 29 Oct 1998 13:35:04 -0800 Date: Thu, 29 Oct 1998 13:35:02 -0800 (PST) From: Tom X-Sender: tom@shell.uniserve.ca To: Rich Winkel cc: stable@FreeBSD.ORG Subject: Re: RAID support in FBSD? In-Reply-To: <199810292052.OAA16290@chumbly.math.missouri.edu> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Thu, 29 Oct 1998, Rich Winkel wrote: > I'm new to this raid stuff. I understand you can get a raid which > hooks to the scsi bus and looks to the computer like an ordinary > (albeit fast) disk. Theoretically this would work without any specific > OS support, right? More than theory. They work. Disadvantages: limited by speed of the RAID box host bus. More overhead before data hits the disk. Advantages: you can configure the unit from an LCD panel, or VT100 terminal. No need to run special software on your server. > The alternative would be a raid card on the PCI bus, which can move > data faster, but would require OS driver support. > > Of course there's a lot to be said for OS-independent hardware, but > aside from the faster speed, are there worthwhile advantages (i.e. > access to special features) to be gained by going with a PCI raid > card? I understand fbsd supports DPT pci controllers. How do > they compare with the competition? DPT has a whole line of host based RAID controllers. They are probably the best you can get. Very wide operating system support, so they are hardly OS depedent. Disadvantages: FreeBSD can't run the dptmgr software, so online re-config and monitoring is not possible. If, you have a smart drive enclosure, this shouldn't be a big problem. Advantages: a DPT PM334 is probably cheaper than a SCSI-SCSI raid unit. It also doesn't need any precious hard bays to be mounted in either. You also get up to 3 UW SCSI channels per PCI slot. > The machine would be a 400mhz xeon, a departmental server, with > an adaptec 2940 ultra wide/fast controller. > > Sorry for the open-ended questions, any faq pointers would be > much appreciated. > > Thanks for any help!!! > > Rich > Tom To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message