From owner-freebsd-fs Thu Nov 5 01:07:28 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id BAA09054 for freebsd-fs-outgoing; Thu, 5 Nov 1998 01:07:28 -0800 (PST) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from ns.wan (trltech.demon.co.uk [194.222.7.191]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id BAA09045 for ; Thu, 5 Nov 1998 01:07:24 -0800 (PST) (envelope-from richard@jezebel.demon.co.uk) Received: from jezebel.demon.co.uk (rdls.dhcp.sw.wan [192.9.201.75]) by ns.wan (8.8.8/8.8.8) with ESMTP id JAA20836 for ; Thu, 5 Nov 1998 09:07:14 GMT (envelope-from richard@jezebel.demon.co.uk) Message-ID: <36416ACE.44FE439B@jezebel.demon.co.uk> Date: Thu, 05 Nov 1998 09:07:26 +0000 From: Richard Smith Organization: http://www.trltech.co.uk X-Mailer: Mozilla 4.05 [en] (WinNT; I) MIME-Version: 1.0 To: freebsd-fs@FreeBSD.ORG Subject: Should a corrupt floppy disk cause a panic? Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org [this question was originally posted to -questions] This is question on policy. The msdosfs will panic and the system will die if you mount a floppy with a corrupt format. I have an image of such a floppy and I can crash my system every time. The error message is: panic: isa_dmacheck: no physical page present syncing disks... panic: msdosfs_lock: locking against myself ...and the system reboots. I am using 2.2.7R and have tested it on three separate systems. The man page for mount effectively says "live with it". So is this a bug or a feature? _______________________________________________________________________ Richard Smith Assistant Chief Engineer TRL Technology Limited To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message From owner-freebsd-fs Thu Nov 5 05:04:39 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id FAA07255 for freebsd-fs-outgoing; Thu, 5 Nov 1998 05:04:39 -0800 (PST) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from sv01.cet.co.jp (sv01.cet.co.jp [210.171.56.2]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id FAA07230 for ; Thu, 5 Nov 1998 05:04:37 -0800 (PST) (envelope-from michaelh@cet.co.jp) Received: from localhost (michaelh@localhost) by sv01.cet.co.jp (8.8.8/8.8.8) with SMTP id NAA10861; Thu, 5 Nov 1998 13:04:36 GMT (envelope-from michaelh@cet.co.jp) Date: Thu, 5 Nov 1998 22:04:36 +0900 (JST) From: Michael Hancock To: Richard Smith cc: freebsd-fs@FreeBSD.ORG Subject: Re: Should a corrupt floppy disk cause a panic? In-Reply-To: <36416ACE.44FE439B@jezebel.demon.co.uk> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org If you have patches that fix the problem they might be accepted. On Thu, 5 Nov 1998, Richard Smith wrote: > [this question was originally posted to -questions] > > This is question on policy. > > The msdosfs will panic and the system will die if you mount a > floppy with a corrupt format. I have an image of such a floppy > and I can crash my system every time. > > The error message is: > > panic: isa_dmacheck: no physical page present > syncing disks... panic: msdosfs_lock: locking against myself > ...and the system reboots. > > I am using 2.2.7R and have tested it on three separate systems. > > The man page for mount effectively says "live with it". > > So is this a bug or a feature? > _______________________________________________________________________ > Richard Smith Assistant Chief Engineer TRL Technology Limited > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-fs" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message From owner-freebsd-fs Fri Nov 6 08:32:55 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id IAA21766 for freebsd-fs-outgoing; Fri, 6 Nov 1998 08:32:55 -0800 (PST) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from datasail.it ([194.177.99.2]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id IAA21748 for ; Fri, 6 Nov 1998 08:32:48 -0800 (PST) (envelope-from bago@datasail.it) Received: from lust (194.177.99.15) by datasail.it with SMTP (Eudora Internet Mail Server 1.1.2); Fri, 6 Nov 1998 18:34:24 +0000 Message-ID: <008e01be09a3$88e06880$0f63b1c2@lust.datasail.it> From: "Bagnara Stefano" To: Subject: RAID1 Software vs Hardware Date: Fri, 6 Nov 1998 17:35:58 +0100 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_008B_01BE09AB.EA4AA290" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 4.72.2106.4 X-MimeOLE: Produced By Microsoft MimeOLE V4.72.2106.4 Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org This is a multi-part message in MIME format. ------=_NextPart_000_008B_01BE09AB.EA4AA290 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I don't know if this is the correct list (sorry if not), anyway: I need to implement a simple raid1 with 2 9gigs SCSI HDD. I need a = inexpensive solution ... so i was thinking about a software raid1. Is it possible? is it too slow? the system will be only a mail server. How can i do hw raid with a low cost card?? and.. what card? thanx u in advance ------=_NextPart_000_008B_01BE09AB.EA4AA290 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
I don't know if this is the correct list (sorry if = not),=20 anyway:
 
I need to implement a simple raid1 = with 2 9gigs=20 SCSI HDD. I need a inexpensive solution ... so i was thinking about a = software=20 raid1.
Is it possible? is it too slow? the = system will=20 be only a mail server.
 
How can i do hw raid with a low cost = card??=20 and.. what card?
 
thanx u in = advance
------=_NextPart_000_008B_01BE09AB.EA4AA290-- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message From owner-freebsd-fs Fri Nov 6 13:36:51 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id NAA06129 for freebsd-fs-outgoing; Fri, 6 Nov 1998 13:36:51 -0800 (PST) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from set.scient.com (set.scient.com [208.202.109.254]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id NAA06121 for ; Fri, 6 Nov 1998 13:36:49 -0800 (PST) (envelope-from enkhyl@scient.com) Received: by set.scient.com; (5.65v4.0/1.3/10May95) id AA28707; Fri, 6 Nov 1998 13:36:23 -0800 Received: from somewhere by smtpxd Date: Fri, 6 Nov 1998 13:35:51 -0800 (PST) From: Christopher Nielsen X-Sender: enkhyl@ender.sf.scient.com Reply-To: enkhyl@hayseed.net To: Bagnara Stefano Cc: freebsd-fs@FreeBSD.ORG Subject: Re: RAID1 Software vs Hardware In-Reply-To: <008e01be09a3$88e06880$0f63b1c2@lust.datasail.it> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Fri, 6 Nov 1998, Bagnara Stefano wrote: > Date: Fri, 6 Nov 1998 17:35:58 +0100 > From: Bagnara Stefano > To: freebsd-fs@FreeBSD.ORG > Subject: RAID1 Software vs Hardware > > I don't know if this is the correct list (sorry if not), anyway: > > I need to implement a simple raid1 with 2 9gigs SCSI HDD. I need a inexpensive solution ... so i was thinking about a software raid1. > Is it possible? is it too slow? the system will be only a mail server. Your really not going to see very good performance with RAID if you're using only two spindles (i.e., discs). You might want to try going with 4 4G discs, if possible. The question of performance is directly related to exactly how much I/O you're going to be shoving through the discs. "Only a mail server" doesn't really provide enough information, IMHO. > How can i do hw raid with a low cost card?? and.. what card? I'll leave this bit to someone else. :-) -- Christopher Nielsen Scient: The eBusiness Systems Innovator cnielsen@scient.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message From owner-freebsd-fs Fri Nov 6 15:50:51 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id PAA23859 for freebsd-fs-outgoing; Fri, 6 Nov 1998 15:50:51 -0800 (PST) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from allegro.lemis.com (allegro.lemis.com [192.109.197.134]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id PAA23851 for ; Fri, 6 Nov 1998 15:50:47 -0800 (PST) (envelope-from grog@freebie.lemis.com) Received: from freebie.lemis.com (freebie.lemis.com [192.109.197.137]) by allegro.lemis.com (8.9.1/8.9.0) with ESMTP id KAA01507; Sat, 7 Nov 1998 10:20:16 +1030 (CST) Received: (from grog@localhost) by freebie.lemis.com (8.9.1/8.9.0) id KAA00798; Sat, 7 Nov 1998 10:20:14 +1030 (CST) Message-ID: <19981107102014.F499@freebie.lemis.com> Date: Sat, 7 Nov 1998 10:20:14 +1030 From: Greg Lehey To: Bagnara Stefano , freebsd-fs@FreeBSD.ORG Subject: Re: RAID1 Software vs Hardware References: <008e01be09a3$88e06880$0f63b1c2@lust.datasail.it> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.91.1i In-Reply-To: <008e01be09a3$88e06880$0f63b1c2@lust.datasail.it>; from Bagnara Stefano on Fri, Nov 06, 1998 at 05:35:58PM +0100 WWW-Home-Page: http://www.lemis.com/~grog Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-41-739-7062 Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org [Format autorecovered at freebie.lemis.com] On Friday, 6 November 1998 at 17:35:58 +0100, Bagnara Stefano wrote: > I don't know if this is the correct list (sorry if not), anyway: The list's OK. Your message is difficult to read, though: one of the lines was 136 characters long. I've corrected the format here. > I need to implement a simple raid1 with 2 9gigs SCSI HDD. I need a > inexpensive solution ... so i was thinking about a software raid1. > Is it possible? Yes. > is it too slow? The software aspects don't make a significant difference in performance. You're still limited by the disks themselves. > the system will be only a mail server. Any idea of the disk data rates? > How can i do hw raid with a low cost card?? and.. what card? Well, it would be a DPT board, but I don't know if it's low cost. For the software alternative, see Vinum (http://www.lemis.com/vinum.html). Greg -- See complete headers for address, home page and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message From owner-freebsd-fs Fri Nov 6 15:52:03 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id PAA24052 for freebsd-fs-outgoing; Fri, 6 Nov 1998 15:52:03 -0800 (PST) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from allegro.lemis.com (allegro.lemis.com [192.109.197.134]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id PAA24026 for ; Fri, 6 Nov 1998 15:51:59 -0800 (PST) (envelope-from grog@freebie.lemis.com) Received: from freebie.lemis.com (freebie.lemis.com [192.109.197.137]) by allegro.lemis.com (8.9.1/8.9.0) with ESMTP id KAA01520; Sat, 7 Nov 1998 10:21:45 +1030 (CST) Received: (from grog@localhost) by freebie.lemis.com (8.9.1/8.9.0) id KAA00811; Sat, 7 Nov 1998 10:21:45 +1030 (CST) Message-ID: <19981107102145.G499@freebie.lemis.com> Date: Sat, 7 Nov 1998 10:21:45 +1030 From: Greg Lehey To: enkhyl@hayseed.net, Bagnara Stefano Cc: freebsd-fs@FreeBSD.ORG Subject: Re: RAID1 Software vs Hardware References: <008e01be09a3$88e06880$0f63b1c2@lust.datasail.it> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.91.1i In-Reply-To: ; from Christopher Nielsen on Fri, Nov 06, 1998 at 01:35:51PM -0800 WWW-Home-Page: http://www.lemis.com/~grog Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-41-739-7062 X-Mutt-References: Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org [Format autorecovered at freebie.lemis.com] On Friday, 6 November 1998 at 13:35:51 -0800, Christopher Nielsen wrote: > On Fri, 6 Nov 1998, Bagnara Stefano wrote: > >> Date: Fri, 6 Nov 1998 17:35:58 +0100 >> From: Bagnara Stefano >> To: freebsd-fs@FreeBSD.ORG >> Subject: RAID1 Software vs Hardware >> >> I don't know if this is the correct list (sorry if not), anyway: I >> need to implement a simple raid1 with 2 9gigs SCSI HDD. I need a >> inexpensive solution ... so i was thinking about a software raid1. >> Is it possible? is it too slow? > > Your really not going to see very good performance with RAID if you're > using only two spindles (i.e., discs). You might want to try going with 4 > 4G discs, if possible. The question of performance is directly related to > exactly how much I/O you're going to be shoving through the discs. "Only a > mail server" doesn't really provide enough information, IMHO. The question was about RAID-1 (mirroring), which is more related to availability than performance. You only need additional disks if you need more than one disk's worth of data. Greg -- See complete headers for address, home page and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message From owner-freebsd-fs Fri Nov 6 16:40:28 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id QAA01268 for freebsd-fs-outgoing; Fri, 6 Nov 1998 16:40:28 -0800 (PST) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from magicnet.magicnet.net (magicnet.magicnet.net [204.96.116.9]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id QAA01263 for ; Fri, 6 Nov 1998 16:40:26 -0800 (PST) (envelope-from bill@bilver.magicnet.net) Received: (from uucp@localhost) by magicnet.magicnet.net (8.8.6/8.8.8) with UUCP id TAA14802 for freebsd-fs@freebsd.org; Fri, 6 Nov 1998 19:35:46 -0500 (EST) Received: (from bill@localhost) by bilver.magicnet.net (8.9.1/8.9.1) id TAA27229 for freebsd-fs@freebsd.org; Fri, 6 Nov 1998 19:42:15 -0500 (EST) From: Bill Vermillion Message-Id: <199811070042.TAA27229@bilver.magicnet.net> Subject: Re: RAID1 Software vs Hardware In-Reply-To: from Christopher Nielsen at "Nov 6, 98 01:35:51 pm" To: freebsd-fs@FreeBSD.ORG Date: Fri, 6 Nov 1998 19:42:15 -0500 (EST) X-Mailer: ELM [version 2.4ME+ PL38 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Christopher Nielsen recently said: > On Fri, 6 Nov 1998, Bagnara Stefano wrote: > > Date: Fri, 6 Nov 1998 17:35:58 +0100 From: Bagnara Stefano > > To: freebsd-fs@FreeBSD.ORG Subject: RAID1 > > Software vs Hardware ^^^^^ > > I need to implement a simple raid1 with 2 9gigs SCSI HDD. I . > > Ineed a inexpensive solution ... so i was thinking about a . > > Isoftware raid1 s it possible? is it too slow? the system will . > > Ibe only a mail server . > Your really not going to see very good performance with RAID if > you're using only two spindles (i.e., discs). You might want > to try going with 4 4G discs, if possible. The question of > performance is directly related to exactly how much I/O you're > going to be shoving through the discs. "Only a mail server" > doesn't really provide enough information, IMHO. I've found that I get a 50% throughput increase (typical)when running RAID 0 with 2 drives. RAID 0 is always the fastest, but any failure will stop you dead. RAID 1 will give no increase in some areas, and writes are slower, but it will boost the read throughput if different files are being accessed, just as if you load balanced multiple single disks.. A good bet is a small boot drive, and then put the stripes on a pair of larger drives. Thus you have the recovery tools in place to restore after a disaster. Otherwise you have to go back to square one and install the OS. Not a big problem in a 2 drive mirror - but still a safety factor. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message From owner-freebsd-fs Fri Nov 6 16:42:38 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id QAA01437 for freebsd-fs-outgoing; Fri, 6 Nov 1998 16:42:38 -0800 (PST) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from set.scient.com (set.scient.com [208.202.109.254]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id QAA01431 for ; Fri, 6 Nov 1998 16:42:34 -0800 (PST) (envelope-from enkhyl@scient.com) Received: by set.scient.com; (5.65v4.0/1.3/10May95) id AA06971; Fri, 6 Nov 1998 16:42:01 -0800 Received: from somewhere by smtpxd Date: Fri, 6 Nov 1998 16:41:23 -0800 (PST) From: Christopher Nielsen X-Sender: enkhyl@ender.sf.scient.com Reply-To: enkhyl@hayseed.net To: Greg Lehey Cc: Bagnara Stefano , freebsd-fs@FreeBSD.ORG Subject: Re: RAID1 Software vs Hardware In-Reply-To: <19981107102145.G499@freebie.lemis.com> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Sat, 7 Nov 1998, Greg Lehey wrote: > Date: Sat, 7 Nov 1998 10:21:45 +1030 > From: Greg Lehey > To: enkhyl@hayseed.net, Bagnara Stefano > Cc: freebsd-fs@FreeBSD.ORG > Subject: Re: RAID1 Software vs Hardware > > [Format autorecovered at freebie.lemis.com] > > On Friday, 6 November 1998 at 13:35:51 -0800, Christopher Nielsen wrote: > > On Fri, 6 Nov 1998, Bagnara Stefano wrote: > > > >> Date: Fri, 6 Nov 1998 17:35:58 +0100 > >> From: Bagnara Stefano > >> To: freebsd-fs@FreeBSD.ORG > >> Subject: RAID1 Software vs Hardware > >> > >> I don't know if this is the correct list (sorry if not), anyway: I > >> need to implement a simple raid1 with 2 9gigs SCSI HDD. I need a > >> inexpensive solution ... so i was thinking about a software raid1. > >> Is it possible? is it too slow? > > > > Your really not going to see very good performance with RAID if you're > > using only two spindles (i.e., discs). You might want to try going with 4 > > 4G discs, if possible. The question of performance is directly related to > > exactly how much I/O you're going to be shoving through the discs. "Only a > > mail server" doesn't really provide enough information, IMHO. > > The question was about RAID-1 (mirroring), which is more related to > availability than performance. You only need additional disks if you > need more than one disk's worth of data. bleh. You're right. Sorry for the misinformation. *reminds self to read more carefully next time* -- Christopher Nielsen Scient: The eBusiness Systems Innovator cnielsen@scient.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message From owner-freebsd-fs Sat Nov 7 01:37:13 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id BAA13838 for freebsd-fs-outgoing; Sat, 7 Nov 1998 01:37:13 -0800 (PST) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from allegro.lemis.com (allegro.lemis.com [192.109.197.134]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id BAA13811 for ; Sat, 7 Nov 1998 01:36:53 -0800 (PST) (envelope-from grog@freebie.lemis.com) Received: from freebie.lemis.com (freebie.lemis.com [192.109.197.137]) by allegro.lemis.com (8.9.1/8.9.0) with ESMTP id UAA03083; Sat, 7 Nov 1998 20:06:21 +1030 (CST) Received: (from grog@localhost) by freebie.lemis.com (8.9.1/8.9.0) id UAA01415; Sat, 7 Nov 1998 20:06:18 +1030 (CST) Message-ID: <19981107200618.O499@freebie.lemis.com> Date: Sat, 7 Nov 1998 20:06:18 +1030 From: Greg Lehey To: Bill Vermillion , freebsd-fs@FreeBSD.ORG Subject: Re: RAID1 Software vs Hardware References: <199811070042.TAA27229@bilver.magicnet.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.91.1i In-Reply-To: <199811070042.TAA27229@bilver.magicnet.net>; from Bill Vermillion on Fri, Nov 06, 1998 at 07:42:15PM -0500 WWW-Home-Page: http://www.lemis.com/~grog Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-41-739-7062 Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Friday, 6 November 1998 at 19:42:15 -0500, Bill Vermillion wrote: > Christopher Nielsen recently said: > >> On Fri, 6 Nov 1998, Bagnara Stefano wrote: > >>> Date: Fri, 6 Nov 1998 17:35:58 +0100 From: Bagnara Stefano >>> To: freebsd-fs@FreeBSD.ORG Subject: RAID1 >>> Software vs Hardware ^^^^^ > >>> I need to implement a simple raid1 with 2 9gigs SCSI HDD. I . >>> Ineed a inexpensive solution ... so i was thinking about a . >>> Isoftware raid1 s it possible? is it too slow? the system will . >>> Ibe only a mail server . > >> Your really not going to see very good performance with RAID if >> you're using only two spindles (i.e., discs). You might want >> to try going with 4 4G discs, if possible. The question of >> performance is directly related to exactly how much I/O you're >> going to be shoving through the discs. "Only a mail server" >> doesn't really provide enough information, IMHO. > > I've found that I get a 50% throughput increase (typical)when > running RAID 0 with 2 drives. That's what theory would tell you. > RAID 0 is always the fastest, but any failure will stop you dead. (if that's all you do). > RAID 1 will give no increase in some areas, and writes are slower, This depends a lot on the configuration. You need to write to every copy (plex in vinum jargon), whereas you only need to read from one. In practice, if you're running SCSI disks or IDEs with UDMA on different controllers, you'll delay the writes to the speed of the slowest disk. On average that's slower than a single disk, but not much. > but it will boost the read throughput if different files are being > accessed, just as if you load balanced multiple single disks.. BTW, ccd always reads from the same copy of the data, so this doesn't work. But in principle you're right. > A good bet is a small boot drive, and then put the stripes on a > pair of larger drives. Thus you have the recovery tools in place > to restore after a disaster. Otherwise you have to go back > to square one and install the OS. Not a big problem in a 2 drive > mirror - but still a safety factor. Agreed Greg -- See complete headers for address, home page and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message From owner-freebsd-fs Sat Nov 7 05:37:48 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id FAA03671 for freebsd-fs-outgoing; Sat, 7 Nov 1998 05:37:48 -0800 (PST) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from magicnet.magicnet.net (magicnet.magicnet.net [204.96.116.9]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id FAA03666 for ; Sat, 7 Nov 1998 05:37:47 -0800 (PST) (envelope-from bill@bilver.magicnet.net) Received: (from uucp@localhost) by magicnet.magicnet.net (8.8.6/8.8.8) with UUCP id IAA13694 for freebsd-fs@freebsd.org; Sat, 7 Nov 1998 08:35:36 -0500 (EST) Received: (from bill@localhost) by bilver.magicnet.net (8.9.1/8.9.1) id IAA10243 for freebsd-fs@freebsd.org; Sat, 7 Nov 1998 08:31:27 -0500 (EST) From: Bill Vermillion Message-Id: <199811071331.IAA10243@bilver.magicnet.net> Subject: Re: RAID1 Software vs Hardware In-Reply-To: <19981107200618.O499@freebie.lemis.com> from Greg Lehey at "Nov 7, 98 08:06:18 pm" To: freebsd-fs@FreeBSD.ORG Date: Sat, 7 Nov 1998 08:31:26 -0500 (EST) X-Mailer: ELM [version 2.4ME+ PL38 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Greg Lehey recently said: > On Friday, 6 November 1998 at 19:42:15 -0500, Bill Vermillion wrote: > > Christopher Nielsen recently said: > > > >> On Fri, 6 Nov 1998, Bagnara Stefano wrote: > > > >>> Date: Fri, 6 Nov 1998 17:35:58 +0100 From: Bagnara Stefano > >>> To: freebsd-fs@FreeBSD.ORG Subject: RAID1 > >>> Software vs Hardware ^^^^^ > >>> I need to implement a simple raid1 with 2 9gigs SCSI HDD. I . > >>> Ineed a inexpensive solution ... so i was thinking about a . > >>> Isoftware raid1 s it possible? is it too slow? the system will . > >>> Ibe only a mail server . > >> Your really not going to see very good performance with RAID if > >> you're using only two spindles (i.e., discs). ... > > I've found that I get a 50% throughput increase (typical)when > > running RAID 0 with 2 drives. > That's what theory would tell you. No - not theory. Measured in real-life - running HW raid 0 - on a clients SCO system. We needed more speed. It may be slightly under 50% - but it's darn close. I have timed the same drive on SCO and FreeBSD - a 9GB 'cudda, and the raw SCO performance through the file-system is in the 3MB/min range, while using the FreeBSD file-system - as shipped - no mods, etc,. it is between 2 and 3 times faster than SCO's. Controller is DPT with a hunk of cache. All timing was done with 100MB minimum file sizes usiing iozone. > > RAID 1 will give no increase in some areas, and writes are slower, > This depends a lot on the configuration. You need to write to every > copy (plex in vinum jargon), whereas you only need to read from one. > In practice, if you're running SCSI disks or IDEs with UDMA on > different controllers, you'll delay the writes to the speed of the > slowest disk. On average that's slower than a single disk, but not > much. I've only used HW RAID devices so I can't comment on the other implementation. The RAID Standards Board (I think that's the correct name) has permitted a pair of striped drives to be designated RAID 0, while in reality it is not a RAID. They current have 6 classes - 0 thru 5 - and there is a chart in Adaptec's book on I/O subsytems listing the pro's'/con's of each. RAID2/3/4 aren't used, and from what I've seen drives that use to have spindle sync for byte/sector striping aren't being made anymore. But with drives now at 20MB/sec+ speeds, the old needs are gone. I can't comment on IDE as I've never used them. > > but it will boost the read throughput if different files are being > > accessed, just as if you load balanced multiple single disks.. > BTW, ccd always reads from the same copy of the data, so this doesn't > work. But in principle you're right. Reading from two disks for different files is one of the touted features of most HW implementations. Bill To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message From owner-freebsd-fs Sat Nov 7 15:19:55 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id PAA21326 for freebsd-fs-outgoing; Sat, 7 Nov 1998 15:19:55 -0800 (PST) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from allegro.lemis.com (allegro.lemis.com [192.109.197.134]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id PAA21319 for ; Sat, 7 Nov 1998 15:19:50 -0800 (PST) (envelope-from grog@freebie.lemis.com) Received: from freebie.lemis.com (freebie.lemis.com [192.109.197.137]) by allegro.lemis.com (8.9.1/8.9.0) with ESMTP id JAA04836; Sun, 8 Nov 1998 09:49:19 +1030 (CST) Received: (from grog@localhost) by freebie.lemis.com (8.9.1/8.9.0) id JAA02764; Sun, 8 Nov 1998 09:49:17 +1030 (CST) Message-ID: <19981108094916.T499@freebie.lemis.com> Date: Sun, 8 Nov 1998 09:49:16 +1030 From: Greg Lehey To: Bill Vermillion , freebsd-fs@FreeBSD.ORG Subject: Re: RAID1 Software vs Hardware References: <19981107200618.O499@freebie.lemis.com> <199811071331.IAA10243@bilver.magicnet.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.91.1i In-Reply-To: <199811071331.IAA10243@bilver.magicnet.net>; from Bill Vermillion on Sat, Nov 07, 1998 at 08:31:26AM -0500 WWW-Home-Page: http://www.lemis.com/~grog Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-41-739-7062 Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Saturday, 7 November 1998 at 8:31:26 -0500, Bill Vermillion wrote: > Greg Lehey recently said: >> On Friday, 6 November 1998 at 19:42:15 -0500, Bill Vermillion wrote: >>> Christopher Nielsen recently said: >>> >>>> On Fri, 6 Nov 1998, Bagnara Stefano wrote: >>> >>>>> Date: Fri, 6 Nov 1998 17:35:58 +0100 From: Bagnara Stefano >>>>> To: freebsd-fs@FreeBSD.ORG Subject: RAID1 >>>>> Software vs Hardware ^^^^^ > >>>>> I need to implement a simple raid1 with 2 9gigs SCSI HDD. I . >>>>> Ineed a inexpensive solution ... so i was thinking about a . >>>>> Isoftware raid1 s it possible? is it too slow? the system will . >>>>> Ibe only a mail server . > >>>> Your really not going to see very good performance with RAID if >>>> you're using only two spindles (i.e., discs). ... > >>> I've found that I get a 50% throughput increase (typical)when >>> running RAID 0 with 2 drives. > >> That's what theory would tell you. > > No - not theory. Measured in real-life - running HW raid 0 - on a > clients SCO system. We needed more speed. It may be slightly > under 50% - but it's darn close. Theory would tell you 50%. Practice shows it's darn close. If I had said "yes, that's what happens", somebody would have looked from the other perspective and said "not quite". > I have timed the same drive on SCO and FreeBSD - a 9GB 'cudda, and > the raw SCO performance through the file-system is in the 3MB/min > range, while using the FreeBSD file-system - as shipped - no mods, > etc,. it is between 2 and 3 times faster than SCO's. Which operating system? > Controller is DPT with a hunk of cache. All timing was done with > 100MB minimum file sizes usiing iozone. > >>> RAID 1 will give no increase in some areas, and writes are slower, > >> This depends a lot on the configuration. You need to write to every >> copy (plex in vinum jargon), whereas you only need to read from one. >> In practice, if you're running SCSI disks or IDEs with UDMA on >> different controllers, you'll delay the writes to the speed of the >> slowest disk. On average that's slower than a single disk, but not >> much. > > I've only used HW RAID devices so I can't comment on the other > implementation. The RAID Standards Board (I think that's the > correct name) has permitted a pair of striped drives to be > designated RAID 0, while in reality it is not a RAID. > > They current have 6 classes - 0 thru 5 - and there is a chart > in Adaptec's book on I/O subsytems listing the pro's'/con's of > each. RAID2/3/4 aren't used, and from what I've seen drives that > use to have spindle sync for byte/sector striping aren't being made > anymore. But with drives now at 20MB/sec+ speeds, the old needs > are gone. Correct. You'd be surprised how many products offer RAID-2/3/4, though. I think the product manager got a checklist to tick off. I have deliberately left these three out of Vinum. > I can't comment on IDE as I've never used them. Shouldn't make much difference with only one drive per controller and UDMA. Otherwise you'll run into significant contention problems. >>> but it will boost the read throughput if different files are being >>> accessed, just as if you load balanced multiple single disks.. > >> BTW, ccd always reads from the same copy of the data, so this doesn't >> work. But in principle you're right. > > Reading from two disks for different files is one of the touted > features of most HW implementations. Put it this way, I don't know of any other implementation, SW or HW, which is this primitive. Vinum has a choice of round robin (default) or always reading from a specific drive (which can be an advantage if you have a ramdisk, for example). Greg -- See complete headers for address, home page and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message From owner-freebsd-fs Sat Nov 7 22:09:50 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id WAA05651 for freebsd-fs-outgoing; Sat, 7 Nov 1998 22:09:50 -0800 (PST) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from panzer.plutotech.com (panzer.plutotech.com [206.168.67.125]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id WAA05637 for ; Sat, 7 Nov 1998 22:09:46 -0800 (PST) (envelope-from ken@panzer.plutotech.com) Received: (from ken@localhost) by panzer.plutotech.com (8.9.1/8.8.5) id XAA14179; Sat, 7 Nov 1998 23:08:31 -0700 (MST) From: "Kenneth D. Merry" Message-Id: <199811080608.XAA14179@panzer.plutotech.com> Subject: Re: RAID1 Software vs Hardware In-Reply-To: <19981108094916.T499@freebie.lemis.com> from Greg Lehey at "Nov 8, 98 09:49:16 am" To: grog@lemis.com (Greg Lehey) Date: Sat, 7 Nov 1998 23:08:30 -0700 (MST) Cc: bill@bilver.magicnet.net, freebsd-fs@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL28s (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Greg Lehey wrote... > On Saturday, 7 November 1998 at 8:31:26 -0500, Bill Vermillion wrote: > > They current have 6 classes - 0 thru 5 - and there is a chart > > in Adaptec's book on I/O subsytems listing the pro's'/con's of > > each. RAID2/3/4 aren't used, and from what I've seen drives that > > use to have spindle sync for byte/sector striping aren't being made > > anymore. But with drives now at 20MB/sec+ speeds, the old needs > > are gone. > > Correct. You'd be surprised how many products offer RAID-2/3/4, > though. I think the product manager got a checklist to tick off. I > have deliberately left these three out of Vinum. RAID 3 is still used, and is still useful. All of Pluto's products (see http://www.plutotech.com) use RAID 3. It works quite well for video data. Ken -- Kenneth Merry ken@plutotech.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message From owner-freebsd-fs Sat Nov 7 23:09:59 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id XAA09549 for freebsd-fs-outgoing; Sat, 7 Nov 1998 23:09:59 -0800 (PST) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from allegro.lemis.com (allegro.lemis.com [192.109.197.134]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id XAA09538 for ; Sat, 7 Nov 1998 23:09:54 -0800 (PST) (envelope-from grog@freebie.lemis.com) Received: from freebie.lemis.com (freebie.lemis.com [192.109.197.137]) by allegro.lemis.com (8.9.1/8.9.0) with ESMTP id RAA06238; Sun, 8 Nov 1998 17:39:23 +1030 (CST) Received: (from grog@localhost) by freebie.lemis.com (8.9.1/8.9.0) id RAA06122; Sun, 8 Nov 1998 17:39:20 +1030 (CST) Message-ID: <19981108173920.N499@freebie.lemis.com> Date: Sun, 8 Nov 1998 17:39:20 +1030 From: Greg Lehey To: "Kenneth D. Merry" Cc: bill@bilver.magicnet.net, freebsd-fs@FreeBSD.ORG Subject: Re: RAID1 Software vs Hardware References: <19981108094916.T499@freebie.lemis.com> <199811080608.XAA14179@panzer.plutotech.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.91.1i In-Reply-To: <199811080608.XAA14179@panzer.plutotech.com>; from Kenneth D. Merry on Sat, Nov 07, 1998 at 11:08:30PM -0700 WWW-Home-Page: http://www.lemis.com/~grog Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-41-739-7062 Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Saturday, 7 November 1998 at 23:08:30 -0700, Kenneth D. Merry wrote: > Greg Lehey wrote... >> On Saturday, 7 November 1998 at 8:31:26 -0500, Bill Vermillion wrote: >>> They current have 6 classes - 0 thru 5 - and there is a chart >>> in Adaptec's book on I/O subsytems listing the pro's'/con's of >>> each. RAID2/3/4 aren't used, and from what I've seen drives that >>> use to have spindle sync for byte/sector striping aren't being made >>> anymore. But with drives now at 20MB/sec+ speeds, the old needs >>> are gone. >> >> Correct. You'd be surprised how many products offer RAID-2/3/4, >> though. I think the product manager got a checklist to tick off. I >> have deliberately left these three out of Vinum. > > RAID 3 is still used, and is still useful. All of Pluto's products (see > http://www.plutotech.com) use RAID 3. It works quite well for video data. I suppose it gives you good throughput. But how do you handle the I/O load? Are you effectively delivering a single video stream? Greg -- See complete headers for address, home page and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message From owner-freebsd-fs Sat Nov 7 23:26:29 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id XAA10662 for freebsd-fs-outgoing; Sat, 7 Nov 1998 23:26:29 -0800 (PST) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from pluto.plutotech.com (mail.plutotech.com [206.168.67.137]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id XAA10657 for ; Sat, 7 Nov 1998 23:26:28 -0800 (PST) (envelope-from gibbs@plutotech.com) Received: from narnia.plutotech.com (narnia.plutotech.com [206.168.67.130]) by pluto.plutotech.com (8.8.7/8.8.5) with ESMTP id AAA03989; Sun, 8 Nov 1998 00:24:23 -0700 (MST) Message-Id: <199811080724.AAA03989@pluto.plutotech.com> X-Mailer: exmh version 2.0.2 2/24/98 To: Greg Lehey cc: "Kenneth D. Merry" , bill@bilver.magicnet.net, freebsd-fs@FreeBSD.ORG Subject: Re: RAID1 Software vs Hardware In-reply-to: Your message of "Sun, 08 Nov 1998 17:39:20 +1030." <19981108173920.N499@freebie.lemis.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Sun, 08 Nov 1998 00:17:36 -0700 From: "Justin T. Gibbs" Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org >> RAID 3 is still used, and is still useful. All of Pluto's products (see >> http://www.plutotech.com) use RAID 3. It works quite well for video data. > >I suppose it gives you good throughput. But how do you handle the I/O >load? Are you effectively delivering a single video stream? RAID 3 is ideal when your data requests are always a multiple of the strip size. In our case, we block video and audio data into a convenient and efficient block size for the current drive configuration / output mode (e.g 625/525 CCR601, compressed 1080I or 720P, 625/525 DVCPRO 25/50Mb). We currently can deliver anywhere from 2 uncompressed DTV streams up to 10 DVCPRO 25Mb streams at a time using a full up system (17 data, two parity, one hot spare). >Greg >-- >See complete headers for address, home page and phone numbers >finger grog@lemis.com for PGP public key -- Justin To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message