Soft updates and power failure

Pete French pete at twisted.org.uk
Tue Feb 8 11:59:39 GMT 2005


> This dissapoints me since the FreeBSD developers says that this shouldn't
> happen with soft updates and that it's much more stable than Linux'
> caching of meta data as well. Why did this happen and does FreeBSD have
> any plans to implement proper journaling?

At a guess you probably have got write caching on some of the drives
enabled. So even though the drive might have said the block has been
written, it's actually in the cache. Theres nothing FreeBSD or Linux or
any OS can do about hardware which lies about what it has done with
the data. IDE drives in particular used to be notorious for this sort
of thing (especially one make that I can't remember the name of).

You can disable caching on SCSI drives using camcontrol to alter the
approrpiate modepage, though I cant remember which page it is.

-bat.




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