[zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-04-10 Thread Edward Ned Harvey
Due to recent experiences, and discussion on this list, my colleague and I performed some tests: Using solaris 10, fully upgraded. (zpool 15 is latest, which does not have log device removal that was introduced in zpool 19) In any way possible, you lose an unmirrored log device, and the OS wi

Re: [zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-04-10 Thread Bob Friesenhahn
On Sat, 10 Apr 2010, Edward Ned Harvey wrote: Using solaris 10, fully upgraded.  (zpool 15 is latest, which does not have log device removal that was introduced in zpool 19)  In any way possible, you lose an unmirrored log device, and the OS will crash, and the whole zpool is permanently gone,

Re: [zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-04-10 Thread Tim Cook
On Sat, Apr 10, 2010 at 10:08 AM, Edward Ned Harvey wrote: > Due to recent experiences, and discussion on this list, my colleague and > I performed some tests: > > > > Using solaris 10, fully upgraded. (zpool 15 is latest, which does not have > log device removal that was introduced in zpool 19)

Re: [zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-04-10 Thread matthew patton
Thanks for the testing. so FINALLY with version > 19 does ZFS demonstrate production-ready status in my book. How long is it going to take Solaris to catch up? ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.or

Re: [zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-04-11 Thread Edward Ned Harvey
> From: Tim Cook [mailto:t...@cook.ms] > > Awesome!  Thanks for letting us know the results of your tests Ed, > that's extremely helpful.  I was actually interested in grabbing some > of the cheaper intel SSD's for home use, but didn't want to waste my > money if it wasn't going to handle the vari

Re: [zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-04-11 Thread Edward Ned Harvey
> From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- > > Thanks for the testing. so FINALLY with version > 19 does ZFS > demonstrate production-ready status in my book. How long is it going to > take Solaris to catch up? Oh, it's been production worthy for some time - Just don't use u

Re: [zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-04-11 Thread Richard Elling
On Apr 11, 2010, at 5:36 AM, Edward Ned Harvey wrote: > > In the event a pool is faulted, I wish you didn't have to power cycle the > machine. Let all the zfs filesystems that are in that pool simply > disappear, and when somebody does "zpool status" you can see why. In general, I agree. How wou

Re: [zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-04-11 Thread Edward Ned Harvey
> From: Richard Elling [mailto:richard.ell...@gmail.com] > > On Apr 11, 2010, at 5:36 AM, Edward Ned Harvey wrote: > > > > In the event a pool is faulted, I wish you didn't have to power cycle > the > > machine. Let all the zfs filesystems that are in that pool simply > > disappear, and when some

Re: [zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-04-11 Thread Daniel Carosone
On Sun, Apr 11, 2010 at 07:03:29PM -0400, Edward Ned Harvey wrote: > Heck, even if the faulted pool spontaneously sent the server into an > ungraceful reboot, even *that* would be an improvement. Please look at the pool property "failmode". Both of the preferences you have expressed are available

Re: [zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-04-11 Thread Edward Ned Harvey
> From: Daniel Carosone [mailto:d...@geek.com.au] > > Please look at the pool property "failmode". Both of the preferences > you have expressed are available, as well as the default you seem so > unhappy with. I ... did not know that. :-) Thank you.

Re: [zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-04-12 Thread Miles Nordin
> "re" == Richard Elling writes: > "dc" == Daniel Carosone writes: re> In general, I agree. How would you propose handling nested re> mounts? force-unmount them. (so that they can be manually mounted elsewhere, if desired, or even in the same place with the middle filesystem mi

Re: [zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-04-12 Thread Carson Gaspar
Miles Nordin wrote: "re" == Richard Elling writes: How do you handle the case when a hotplug SATA drive is powered off unexpectedly with data in its write cache? Do you replay the writes, or do they go down the ZFS hotplug write hole? If zfs never got a positive response to a cache flush,

Re: [zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-04-12 Thread Carson Gaspar
Carson Gaspar wrote: Miles Nordin wrote: "re" == Richard Elling writes: How do you handle the case when a hotplug SATA drive is powered off unexpectedly with data in its write cache? Do you replay the writes, or do they go down the ZFS hotplug write hole? If zfs never got a positive resp

Re: [zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-04-12 Thread Edward Ned Harvey
> Carson Gaspar wrote: > > Does anyone who understands the internals better than care to take a > stab at what happens if: > > - ZFS writes data to /dev/foo > - /dev/foo looses power and the data from the above write, not yet > flushed to rust (say a field tech pulls the wrong drive...) > - /dev/

Re: [zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-06-29 Thread Arne Jansen
Edward Ned Harvey wrote: > Due to recent experiences, and discussion on this list, my colleague and > I performed some tests: > > Using solaris 10, fully upgraded. (zpool 15 is latest, which does not > have log device removal that was introduced in zpool 19) In any way > possible, you lose an un

Re: [zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-06-30 Thread Edward Ned Harvey
> From: Arne Jansen [mailto:sensi...@gmx.net] > > Edward Ned Harvey wrote: > > Due to recent experiences, and discussion on this list, my colleague > and > > I performed some tests: > > > > Using solaris 10, fully upgraded. (zpool 15 is latest, which does > not > > have log device removal that wa

Re: [zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-06-30 Thread Ray Van Dolson
On Wed, Jun 30, 2010 at 09:47:15AM -0700, Edward Ned Harvey wrote: > > From: Arne Jansen [mailto:sensi...@gmx.net] > > > > Edward Ned Harvey wrote: > > > Due to recent experiences, and discussion on this list, my colleague > > and > > > I performed some tests: > > > > > > Using solaris 10, fully u

Re: [zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-06-30 Thread Ragnar Sundblad
On 12 apr 2010, at 22.32, Carson Gaspar wrote: > Carson Gaspar wrote: >> Miles Nordin wrote: "re" == Richard Elling writes: >>> How do you handle the case when a hotplug SATA drive is powered off >>> unexpectedly with data in its write cache? Do you replay the writes, or do >>> they g

Re: [zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-06-30 Thread Garrett D'Amore
On Wed, 2010-06-30 at 22:28 +0200, Ragnar Sundblad wrote: > To be safe, the protocol needs to be able to discover that the devices > (host or disk) has been disconnected and reconnected or has been reset > and that either parts assumptions about the state of the other has to > be invalidated. > >

Re: [zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-06-30 Thread Ragnar Sundblad
On 30 jun 2010, at 22.46, Garrett D'Amore wrote: > On Wed, 2010-06-30 at 22:28 +0200, Ragnar Sundblad wrote: > >> To be safe, the protocol needs to be able to discover that the devices >> (host or disk) has been disconnected and reconnected or has been reset >> and that either parts assumptions

Re: [zfs-discuss] What happens when unmirrored ZIL log device is removed ungracefully

2010-06-30 Thread Carson Gaspar
Ragnar Sundblad wrote: I was referring to the case where zfs has written data to the drive but still hasen't issued a cache flush, and before the cache flush the drive is reset. If zfs finally issues a cache flush and then isn't informed that the drive has been reset, data is lost. I hope this