zfs discuss - Jan 2011 - kernel panic on USB disk power loss

I was copying a filesystem using "zfs send | zfs receive" and
inadvertently unplugged the power to the USB disk that was the destination.  
Much to my horror this caused the system to panic.  I recovered fine on
rebooting, but it *really* unnerved me.

I don''t find anything about this online.  I would expect it would trash
the copy operation, but the panic seemed a bit extreme.

It''s an Ultra 20 running Solaris 10 Generic_137112-02

I''ve got a copy of U8 I''m planning to install as the U9
license seems to prohibit my using it.

Suggestions?  I''d like to understand what happened and why the system
went down.

Thanks,
Reg
-- 
This message posted from opensolaris.org

On Jan 15, 2011, at 10:33 AM, Reginald Beardsley wrote:
> I was copying a filesystem using "zfs send | zfs receive" and
inadvertently unplugged the power to the USB disk that was the destination.  
Much to my horror this caused the system to panic.  I recovered fine on
rebooting, but it *really* unnerved me.
> 
> I don''t find anything about this online.  I would expect it would
trash the copy operation, but the panic seemed a bit extreme.
> 
> It''s an Ultra 20 running Solaris 10 Generic_137112-02
> 
> I''ve got a copy of U8 I''m planning to install as the U9
license seems to prohibit my using it.
> 
> Suggestions?  I''d like to understand what happened and why the
system went down.
Long, long ago the default failure mode for failed writes was panic.
This was changed for several years ago with the introduction of the
"failmode" property.  Since ZFS is ported to Solaris 10, perhaps the
failmode property is not available until you upgrade?  To see:
	zpool get all poolname
If there is no failmode property, then upgrade.
 -- richard

--- On Wed, 1/19/11, Richard Elling <richard.elling at gmail.com> wrote:
> From: Richard Elling <richard.elling at gmail.com>
> Subject: Re: [zfs-discuss] kernel panic on USB disk power loss
> To: "Reginald Beardsley" <pulaskite at yahoo.com>
> Cc: zfs-discuss at opensolaris.org
> Date: Wednesday, January 19, 2011, 8:59 AM
> On Jan 15, 2011, at 10:33 AM,
> Reginald Beardsley wrote:
> 
> > I was copying a filesystem using "zfs send | zfs
> receive" and inadvertently unplugged the power to the USB
> disk that was the destination.???Much to my
> horror this caused the system to panic.? I recovered
> fine on rebooting, but it *really* unnerved me.
> > 
> > I don''t find anything about this online.? I would
> expect it would trash the copy operation, but the panic
> seemed a bit extreme.
> > 
> > It''s an Ultra 20 running Solaris 10 Generic_137112-02
> > 
> > I''ve got a copy of U8 I''m planning to install as the
> U9 license seems to prohibit my using it.
> > 
> > Suggestions?? I''d like to understand what
> happened and why the system went down.
> 
> Long, long ago the default failure mode for failed writes
> was panic.
> This was changed for several years ago with the
> introduction of the
> "failmode" property.? Since ZFS is ported to Solaris
> 10, perhaps the
> failmode property is not available until you upgrade??
> To see:
> ??? zpool get all poolname
> If there is no failmode property, then upgrade.
>  -- richard
> 
> 
Thanks.  That probably explains it.  The last update on the system was before
ZFS root was available.  I''m in the long delayed process of upgrading
to U8 and taking my main network offline w/ just a minimal system connected to
the Internet.  The browsers are just too vulnerable.

Eventually I''ll migrate to OpenIndiana for all my Solaris instances. 
But for now mirrored ZFS on U8 will have to do since U9 is So Larry''s.