Thus spake Nate Lawson <[EMAIL PROTECTED]>: > On Fri, 24 Jan 2003, David Schultz wrote: > > Thus spake Greg Lehey <[EMAIL PROTECTED]>: > > > I've been thinking about what happened, and I have a possibility: the > > > session before shutdown included a lot of writing to that file system, > > > and I did a shutdown -p. It's possible that the shutdown powered off > > > the system before the disk had flushed its cache. For the moment I'm > > > avoiding shutdown -p, but when I get home I'll try to provoke it > > > again. > > > > FreeBSD's ``fix'' for this problem is the same as Windows 98's. > > Specifically, there is a 5-second delay (tuneable: > > kern.shutdown.poweroff_delay) after all buffers are flushed but > > before the power is cut. Maybe we ought to be sending FLUSH > > CACHE commands to all drives and waiting for them to finish. > > da(4) does a SYNC CACHE (see daclose() and dashutdown()).
Good. I was referring to IDE in this case, because I assume that's what Greg's laptop uses. The ATA driver flushes the cache when the device is closed, but I don't think that happens during shutdown. It probably needs to register a shutdown hook like the SCSI driver. Also, the driver is a bit optimistic about how long the flush will take; it times out after 5 seconds, whereas the ATA spec says a flush can take up to 30 seconds. To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
