I don't think the disk snapshot from a freeze would be any better in terms of data integrity. You're still snapshotting a disk with things like open files - and the guest is in an unknown state processing wise.
If there was a facility to restore disks and then resume processing where the guest left off - it might work.. But you need something to dump and restore memory/pages/etc as well. Sort of like 'hibernate' on a laptop. Scott Rohling On Thu, Aug 30, 2012 at 8:11 AM, Aria Bamdad <[email protected]> wrote: > Just curious, could this functionality be used somehow to allow for a > **consistent** disk snapshot using flashcopy for a live Linux guest? What > I > mean is that currently, we have to shutdown the guest, do the flashcopy and > then restart the guest. Is there a way we can tell the Linux guest to > freeze, take a snapshot of the disks and then resume? > > -----Original Message----- > From: Linux on 390 Port [mailto:[email protected]] On Behalf Of Rob > van der Heij > Sent: Thursday, August 30, 2012 7:47 AM > To: [email protected] > Subject: Re: LGR guest quiesce > > On 30 August 2012 11:43, Lu GL Gao <[email protected]> wrote: > > Linux guest move its memory to target z/VM member during relocating. Then > > it quiesce and resume on target z/VM. > > How to understand "quiesce"? What state of linux when it is in quiesce > > time? Is idling? shutdown? or something? > > > > See it as "frozen while running" - as long as Linux is actually running, > it may change memory that z/VM already copied over, so z/VM will copy it > again, and again... To stop that, finally the guest is frozen for a very > short period, not making any further changes. That gives z/VM time to copy > the last bits and the guest then continues to run on the other side, at the > very instruction where it was frozen before. > Linux will observe that some time passed where it did not run, but that's > normal in time sharing. > > Rob > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO LINUX-390 or > visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > ---------------------------------------------------------------------- > For more information on Linux on System z, visit > http://wiki.linuxvm.org/ > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO LINUX-390 or > visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > ---------------------------------------------------------------------- > For more information on Linux on System z, visit > http://wiki.linuxvm.org/ > ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
