On Fri, Jan 13, 2006 at 12:22:29PM -0500, Gaspar Bakos wrote: > I am trying to figure our what is causing it: > hardware error? If yes, harddrive or memory? I can't help you there. > One clue; some of the last files that were open before the freeze will > contain only \0 characters. > > E.g. > > bash$ od -c .lastfile > 0000000 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 > * > 0010740 \0 \0 \0 \0 \0 \0 \0 \0 \0 > 0010751 > > This is quite annoying as you may imagine. This is a "feature" of metadata-only journaling filesystems such as XFS, where a file can be extended, but its blocks haven't hit the disk yet. As a security precaution, those blocks are replaced with zeros, rather than the stale contents of the disk blocks at the time of the crash, for security reasons. Ext3's default "data=ordered" mode guarantees that this will not happen. Ext3 "data=writeback" can expose stale disk blocks. There's some discussion of this in Daniel Robbins's filesystem articles at IBM developerWorks: http://www-128.ibm.com/developerworks/linux/library/l-fs11.html Ext3, despite its warts, really is a solid bit of engineering -- and still improving! :-) Regards, Bill Rugolsky
