From mboxrd@z Thu Jan 1 00:00:00 1970 From: dave@horsfall.org (Dave Horsfall) Date: Fri, 12 May 2017 09:47:01 +1000 (EST) Subject: [TUHS] The evolution of Unix facilities and architecture In-Reply-To: <20170511222547.GJ4341@mcvoy.com> References: <20170511140729.2262B18C09A@mercury.lcs.mit.edu> <013b01d2ca96$6901b370$3b051a50$@ronnatalie.com> <20170511222547.GJ4341@mcvoy.com> Message-ID: On Thu, 11 May 2017, Larry McVoy wrote: [...] > Try the same thing with Linux. The file system will come back, starting > with, I believe, ext2. That's a journalled FS, isn't it? In which case the transactions get replayed. > My belief is that Linux orders writes such that while you may lose data > (as in, a process created a file, the OS said it was OK, but that file > will not be in the file system after a crash), but the rest of the file > system will be consistent. I think it's as if you powered off the > machine a few seconds earlier than you actually did, some stuff is in > flight and until they can write stuff out in the proper order you may > lose data on a hard reset. And FreeBSD (at least) has been doing ordered writes for quite some time. -- Dave Horsfall DTM (VK2KFU) "Those who don't understand security will suffer."