[TUHS] Illumos )

[Dave Horsfall]

On Tue, 6 Jan 2015, Clem Cole wrote:

> Also, for those of you that never saw Unix before fsck or before the 
> work that Goble did at Purdue to get the write ordering down, you have 
> no idea what it was like to put a file system back together.

Somewhere, deep in Minnie's bowels, is the article I wrote, explaining 
exactly how to use icheck/ncheck/dcheck/clri etc.  I'm told it's saved the 
bacon of quite a few people (assuming it was savable at all).

> The sync;sync;sync stuff was because of the lack write ordering; but 
> even with that, small file system corruptions where common.

It was drilled into us that the correct usage was:

# sync
# sync
# sync

This gives the disk buffers time to actually flush (the writes were merely 
scheduled, and were asynchronous).

-- 
Dave Horsfall DTM (VK2KFU)  "Bliss is a MacBook with a FreeBSD server."
http://www.horsfall.org/spam.html (and check the home page whilst you're there)