From mboxrd@z Thu Jan 1 00:00:00 1970 From: tim.newsham@gmail.com (Tim Newsham) Date: Thu, 17 Jul 2014 16:52:01 -1000 Subject: [TUHS] shutdown for pre-v7 unix In-Reply-To: <2DF13A78-6D26-4E01-A65A-7746A51F44FB@ronnatalie.com> References: <699EC97F-61D6-4102-99E1-8752E8CBD381@bsdimp.com> <2DF13A78-6D26-4E01-A65A-7746A51F44FB@ronnatalie.com> Message-ID: One sync for the disks and two for the operator's peace of mind... On Thu, Jul 17, 2014 at 4:26 PM, Ronald Natalie wrote: > > On Jul 17, 2014, at 4:16 PM, Clem Cole wrote: > > I think that's is a problem in that it needs to be data blocks, inodes, and > finally superblocks to do the least damage in a crash. > > > That is definitely the case and that was perhaps the biggest fix in BSD (and > other later) was to make the file system writing more consistent so at least > you didn't get trashed filesystems but at worst got some orphaned blocks > that needed intervention to reclaim. > > It was mandatory for operators at JHU to understand how the file system was > laid out on disk, and what icheck/dcheck reported and what the options to > fix things. Link counts that were too low and dups in free should NEVER > happen with an intelligently ordered set of I/O operations, but thats not > what Version 6 UNIX had. It wasn't uncommon to find several errors in the > file system that would be degenerate system faults if not corrected. > > But all that aside, even in those shakey days, typing sync multiple times > really didn't accomplish anything and it because less useful as the file > systems became more stable. > > > > _______________________________________________ > TUHS mailing list > TUHS at minnie.tuhs.org > https://minnie.tuhs.org/mailman/listinfo/tuhs > -- Tim Newsham | www.thenewsh.com/~newsham | @newshtwit | thenewsh.blogspot.com