Re: Sync and reboot (was: Re: system.map)

Andre Hedrick
2002-01-03T11:20:58Z

Sorry but if the patch of mine gets accepted there is a notifier hook that
first flushes_cache and holds for the return, then spins down the disks.

The cache_flushes are called always in addition if you were to look
closely at the new driver, each time you unmount a partition the disk is
flushed. Overkill sure, but you will always have at least one flush cache
on a drive that has never been mounted. You will have a min of 3 flush
cache calls on a drive which is mounted.

1 for each partition mounted.
1 of dec the usage counter to 0.
1 for deregistering the device.

Regards,

On Thu, 3 Jan 2002, Miquel van Smoorenburg wrote:

> According to vda:
> > However, then my shutdown script waits 5 secs before hard rebooting the box:
> > there is no way to be sure that IDE drives flushed their cache, except for
> > large pause.
>
> There is, and sysvinit-2.83 implements it ;)
>
> > (There may be some IDE command to do it, but who said each and every drive
> > will implement it? (and will do it correctly, i.e. would not lie to us that
> > cache is written back) :-)
>
> There's supposed to be an IDE command but it depends on task files and
> what not according to Andre Hedrick.
>
> However there is another way. Putting the drive in standby mode also
> flushes the write cache, and reboot/halt from sysvinit 2.83 and up
> look for all IDE drives and put them in standby mode just before calling
> the kernel's hard reboot/halt.
>
> Ofcourse the kernel should do that itself, the IDE driver should
> register a reboot handler that does this - but it doesn't, so I
> put it in sysvinit for now.
>
> Mike.
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Andre Hedrick
CEO/President, LAD Storage Consulting Group
Linux ATA Development
Linux Disk Certification Project