On Thursday 08 December 2005 19:46, Jeff Dike wrote: > On Thu, Dec 08, 2005 at 10:57:35AM -0600, Rob Landley wrote: > > What we really want are write barriers (which I don't believe Linux > > exposes to userspace but I'm not sure), and for UBD to propogate through > > actual fsync requests to the underlying OS.
> If the host crashes, then some number of issued requests may not have > reached the disk, and there is the possibility that the ubd image may > not be recoverable. However, I have crashed a number of hosts, and > never seen this, and I don't remember ever hearing of it happening. On this point, I'd note it depends on the fs. Ext3 seems reliable, but there are reports of hard crashes with Reiserfs. It must be said that it was when Reiserfs supported only data=writeback - now it supports and defaults to data=ordered, like ext3, which is safer. -- Inform me of my mistakes, so I can keep imitating Homer Simpson's "Doh!". Paolo Giarrusso, aka Blaisorblade (Skype ID "PaoloGiarrusso", ICQ 215621894) http://www.user-mode-linux.org/~blaisorblade ___________________________________ Yahoo! Mail: gratis 1GB per i messaggi e allegati da 10MB http://mail.yahoo.it ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://ads.osdn.com/?ad_id=7637&alloc_id=16865&op=click _______________________________________________ User-mode-linux-user mailing list User-mode-linux-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
