Fargusson.Alan wrote:
Doing a dd on a device goes through the cache, so in this case the cache can't be the problem.
This is not the case. In fact, the page cache is indexed by address spaces and each file as well as each block device has its own address space. Consequently, Linux cannot tell that you're reading/writing the same block on disk via the device node that is already in the cache because it belongs to a file of a mounted filesystem that relies on there.
The only safe way of doing an online snapshot of a mounted file system is the dm-snapshot target. Flashcopy and DD don't do the trick. ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
