init 5 on an Ultra 5

init 5 on an Ultra 5

Post by Dale Dietric » Mon, 04 Feb 2002 17:40:11



I have heard that there is an issue with using init 5 on an Ultra-5.  It has
to do with the drives being IDE instead of SCSI.  I have an Ultra-5 that
seems to have problems when an init 5 is done to shut it down.  The disk
seems to always be jacked up when I bring it back up. Has anyone else seen
this problem.  It doesn't happen all the time, but it happened during a
pretty critical time when the last incident happened.
Thanks in advance for any replies.
Dale
 
 
 

init 5 on an Ultra 5

Post by Logan Sh » Mon, 04 Feb 2002 20:52:39




>I have heard that there is an issue with using init 5 on an Ultra-5.  It has
>to do with the drives being IDE instead of SCSI.  I have an Ultra-5 that
>seems to have problems when an init 5 is done to shut it down.  The disk
>seems to always be jacked up when I bring it back up. Has anyone else seen
>this problem.  It doesn't happen all the time, but it happened during a
>pretty critical time when the last incident happened.

I'm not sure if this is the same issue, but there is a patch for
Windows for something similar.  Apparently, some IDE drives these days
come with write caches.  If you turn the power off too quickly, they
don't finish writing the stuff to the disk, and you can lose data.

So if on the Sun you just do "init 0" and then type "poweroff" (or hit
the switch) yourself, you give the IDE drive those few extra seconds it
needs to write the data to permanent storage, and everything's fine.

If this is the case, there are two things you might be able to do to
fix it.  The first is to fix the drive so it doesn't do this in the
first place.  Caching writes in volatile storage is a stupid idea
anyway, IMO, so you'd want to turn it off even it weren't causing this
specific problem.  The second would be to try to modify a few files to
attempt to make Solaris work around it by giving the disks time to
write out that data.  You might try adding "sync; sleep 5" to the very
end of /sbin/rc5.  I'm not 100% sure that's the right place, but I
think it is.

Hope that helps.

  - Logan
--
"I'll tell you something.  Luxury disgusts me."  Giorgio Armani, Jan 17, 2002
( http://dailynews.yahoo.com/h/nm/20020117/re/life_fashion_armani_dc_1.... )

 
 
 

init 5 on an Ultra 5

Post by Thomas Tornblo » Tue, 05 Feb 2002 00:06:46





> >I have heard that there is an issue with using init 5 on an Ultra-5.  It has
> >to do with the drives being IDE instead of SCSI.  I have an Ultra-5 that
> >seems to have problems when an init 5 is done to shut it down.  The disk
> >seems to always be jacked up when I bring it back up. Has anyone else seen
> >this problem.  It doesn't happen all the time, but it happened during a
> >pretty critical time when the last incident happened.

> I'm not sure if this is the same issue, but there is a patch for
> Windows for something similar.  Apparently, some IDE drives these days
> come with write caches.  If you turn the power off too quickly, they
> don't finish writing the stuff to the disk, and you can lose data.

Yep, this is the problem.

I have been working on this issue, bugid 4380416, and one of the tests
we did was to feed power to the disk from a separate power supply, and
we never saw the problem then.

The problem was introduced with when a new Seagate disk was used that
had the write cache enabled from Seagate.

This problem should be fixed as of Solaris 7. What Solaris version is
the original poster running?

Quote:

> So if on the Sun you just do "init 0" and then type "poweroff" (or hit
> the switch) yourself, you give the IDE drive those few extra seconds it
> needs to write the data to permanent storage, and everything's fine.

This works fine.

Quote:> If this is the case, there are two things you might be able to do to
> fix it.  The first is to fix the drive so it doesn't do this in the
> first place.  Caching writes in volatile storage is a stupid idea
> anyway, IMO, so you'd want to turn it off even it weren't causing this
> specific problem.  The second would be to try to modify a few files to
> attempt to make Solaris work around it by giving the disks time to
> write out that data.  You might try adding "sync; sleep 5" to the very
> end of /sbin/rc5.  I'm not 100% sure that's the right place, but I
> think it is.

We tried this, and unfortunately this doesn't help.

Quote:

> Hope that helps.

>   - Logan
> --
> "I'll tell you something.  Luxury disgusts me."  Giorgio Armani, Jan 17, 2002
> ( http://dailynews.yahoo.com/h/nm/20020117/re/life_fashion_armani_dc_1.... )

Thomas
 
 
 

init 5 on an Ultra 5

Post by Circusj.. » Tue, 05 Feb 2002 00:54:58


On Sun, 03 Feb 2002 08:40:11 GMT, "Dale Dietrich"


>I have heard that there is an issue with using init 5 on an Ultra-5.  It has
>to do with the drives being IDE instead of SCSI.  I have an Ultra-5 that
>seems to have problems when an init 5 is done to shut it down.  The disk
>seems to always be jacked up when I bring it back up. Has anyone else seen
>this problem.  It doesn't happen all the time, but it happened during a
>pretty critical time when the last incident happened.
>Thanks in advance for any replies.
>Dale

I have seen Problems using Init 5 on Both ultra 5 and 10 of it not
syncing the drives correctly.

I never really looked into it , I just stopped using Init 5

 
 
 

init 5 on an Ultra 5

Post by ultraspa.. » Tue, 05 Feb 2002 03:56:51



Quote:>I have heard that there is an issue with using init 5 on an Ultra-5.

i had the same problem.

Quote:>It has to do with the drives being IDE instead of SCSI.

sort of, it had to do with the drive caches being in write-back mode
instead of write-through so there was data in the caches that had not
yet been written to the platters before the power was yanked.

i'm pretty sure the problem went away when i upgraded to Solaris 8 10/00
so the fix is probably in one of the patches that release is based on.