From owner-freebsd-questions@freebsd.org Sat Aug 29 05:19:54 2020 Return-Path: Delivered-To: freebsd-questions@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 9F9D43CDB7C for ; Sat, 29 Aug 2020 05:19:54 +0000 (UTC) (envelope-from SRS0=I5nt=CH=mail.sermon-archive.info=doug@sermon-archive.info) Received: from mail.sermon-archive.info (sermon-archive.info [71.177.216.148]) by mx1.freebsd.org (Postfix) with ESMTP id 4BdlCF4tfZz3gq1 for ; Sat, 29 Aug 2020 05:19:53 +0000 (UTC) (envelope-from SRS0=I5nt=CH=mail.sermon-archive.info=doug@sermon-archive.info) Received: from [10.0.1.251] (mini [10.0.1.251]) by mail.sermon-archive.info (Postfix) with ESMTPSA id 4BdlCD3KKgz2fjQV; Fri, 28 Aug 2020 22:19:52 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.15\)) Subject: Re: (very OT) Ideal partition schemes (history of partitioning) From: Doug Hardie In-Reply-To: Date: Fri, 28 Aug 2020 22:19:52 -0700 Cc: FreeBSD Mailing List Content-Transfer-Encoding: quoted-printable Message-Id: References: To: Aryeh Friedman X-Mailer: Apple Mail (2.3445.104.15) X-Virus-Scanned: clamav-milter 0.101.4 at mail X-Virus-Status: Clean X-Rspamd-Queue-Id: 4BdlCF4tfZz3gq1 X-Spamd-Bar: - Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of SRS0=I5nt=CH=mail.sermon-archive.info=doug@sermon-archive.info designates 71.177.216.148 as permitted sender) smtp.mailfrom=SRS0=I5nt=CH=mail.sermon-archive.info=doug@sermon-archive.info X-Spamd-Result: default: False [-1.39 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; FORGED_SENDER(0.30)[bc979@lafn.org,SRS0=I5nt=CH=mail.sermon-archive.info=doug@sermon-archive.info]; ARC_NA(0.00)[]; FROM_HAS_DN(0.00)[]; MV_CASE(0.50)[]; R_SPF_ALLOW(-0.20)[+ip4:71.177.216.148]; TAGGED_RCPT(0.00)[]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[lafn.org: no valid DMARC record]; NEURAL_HAM_LONG(-0.89)[-0.893]; TO_MATCH_ENVRCPT_SOME(0.00)[]; TO_DN_ALL(0.00)[]; NEURAL_HAM_SHORT(-0.23)[-0.230]; RCPT_COUNT_TWO(0.00)[2]; NEURAL_HAM_MEDIUM(-0.86)[-0.865]; FREEMAIL_TO(0.00)[gmail.com]; RCVD_NO_TLS_LAST(0.10)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:5650, ipnet:71.177.216.0/23, country:US]; FROM_NEQ_ENVFROM(0.00)[bc979@lafn.org,SRS0=I5nt=CH=mail.sermon-archive.info=doug@sermon-archive.info]; MAILMAN_DEST(0.00)[freebsd-questions]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 29 Aug 2020 05:19:54 -0000 > On 28 August 2020, at 20:08, Aryeh Friedman = wrote: >=20 > When installing another OS then FreeBSD (won't state which one to = avoid > flame wars) I noticed it's default partitioning scheme breaks the main = (and > only) drive on the system down into 50 GB chunks (in my case / and = /home) > by default (I over road to FreeBSD's default of one big partition for = the > whole drive [minus swap]). >=20 > I was wondering what people think of different generalized = partitioning > schemes? (there is no right answer here but I might question your = comments) >=20 > Also why are partitioned need at all? (both currently and = historically) I may not be the best to address this, but I have been running systems = since the late 60's. In the (not so good old days) the disk drives were = unreliable, the drivers were unreliable, and software was unreliable. = Disks had no partitions. So if any of the disk control tables got = corrupted, generally you had a worthless drive. It had to be completely = restored. I went so far as to dump a good disk setup to punched cards = (lots of them) so that when corruption occurred, I could easily, but not = quickly, restore the disk to a working state. As disks got bigger, someone came up with the partition concept. You = would put the stuff that the system needs to run in one "read only" = partition. In theory, it would not get corrupted by problems with other = partitions. Unix used the / partition to hold most of that. /var was = generally a separate partition because its contents were always = changing. Likewise with /tmp. User partitions were often setup so that = a rogue user would not corrupt other users. Often, if you had the = money, some of those partitions would be put on different drives. The problem with this approach showed up as system software increased in = size. For example, the first FBSD systems I use were setup for 3.5 and = 3.7. The / partition was doubled what the best practice said was = needed. Var and tmp were in separate partitions as was user data. = Somewhere around FBSD 5 or 6, I was no longer able to upgrade the = kernel. The kernel was larger than the / partition. These were = production system with no acceptable down time. I had to purchase four = new systems and repartition the drives with much larger partitions for = /, var, and tmp. Then everything had to be rebuilt, and the systems = swapped. There was still a lot of down time. Then OSX arrived and it used only one partition for everything. At = first I thought that was going to be a disaster, but it was not. UFS = was by that time quite stable. I have never encountered an issue with = it, although others have. Not long after that, I encountered the same = issue with FBSD. The / partition was now smaller than the most recent = kernel. I had to delete all the symbol files from the kernel to be able = to update a system. As a result, I bought more drives, and partitioned = them as a single partition which is now what I run on all my systems. = Often I will put archival information on a second drive, or a second = system. Interestingly enough, OSX has recently gone to multiple = partitions. In this situation Apple is trying to prevent anyone from = modifying their code. I do recall one situation, probably in the FBSD 4 era where syslog went = berserk and completely wrote over the entire var partition. As a side note, a friend of mine in college worked at IBM in San Jose on = OS360. His job was to take all of the example code in the assembler = reference manual, punch them up and run them to ensure that they = actually worked. There was only one 360 working so everything ran on = it. His jobs were the lowest priority, so he had to wait days sometimes = to get them run. Once, he was in the computer room watching them run = and every disk was actively writing at max speed. Since none of code = wrote anything anywhere, he was a bit concerned. So was the operator = and he quickly terminated the jobs. But the damage was done. All of = the single copy of the OS 360 source had been overwritten. As I recall, = both he and the rest of the OS team were terminated. OS 360 was already = years late at that point. I don't recall OS 360 supporting disk = partitioning. -- Doug