* [9fans] fossil 'halt' command?
@ 2009-04-13 11:54 Venkatesh Srinivas
2009-04-13 17:26 ` Charles Forsyth
0 siblings, 1 reply; 3+ messages in thread
From: Venkatesh Srinivas @ 2009-04-13 11:54 UTC (permalink / raw)
To: 9fans
Hi,
extract from the fossil paper:
> The block cache uses soft updates [1] to ensure that the on-disk file
> system is always self-consistent. Thus there is no halt console
> command and no need to check a file system that was shut down without
> halting.
Fossil does have a halt command and does often need checking after an
unexpected shutdown... Any reason why? Was it just observed that it was
needed? Or that soft updates weren't enough?
Thanks,
-- vs
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [9fans] fossil 'halt' command? 2009-04-13 11:54 [9fans] fossil 'halt' command? Venkatesh Srinivas @ 2009-04-13 17:26 ` Charles Forsyth 2009-04-13 23:26 ` erik quanstrom 0 siblings, 1 reply; 3+ messages in thread From: Charles Forsyth @ 2009-04-13 17:26 UTC (permalink / raw) To: 9fans i'd have thought that soft updates ensure consistency, but a halt command ensures that all the changes are actually written. ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [9fans] fossil 'halt' command? 2009-04-13 17:26 ` Charles Forsyth @ 2009-04-13 23:26 ` erik quanstrom 0 siblings, 0 replies; 3+ messages in thread From: erik quanstrom @ 2009-04-13 23:26 UTC (permalink / raw) To: 9fans On Mon Apr 13 18:55:24 EDT 2009, forsyth@terzarima.net wrote: > i'd have thought that soft updates ensure consistency, > but a halt command ensures that all the changes are actually written. i think your point is a good one and definately true (and begs the question of disk caches), but given the paper, one does wonder. halt didn't show up until here http://9fans.net/archive/2003/04/218 but there are later notes, e.g., http://9fans.net/archive/2003/11/66 that fossil was a bit difficult to shutdown cleanly. i'm not sure if that was in reference to the chicken-and-egg nature of the fossil/venti shutdown process or a problem with fossil. - erik ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2009-04-13 23:26 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2009-04-13 11:54 [9fans] fossil 'halt' command? Venkatesh Srinivas 2009-04-13 17:26 ` Charles Forsyth 2009-04-13 23:26 ` erik quanstrom
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