Thanks for the link to that document Marcy. I think the CP STOP/BEGIN method would be the best solution for when you want to take a flashcopy of a live and still running guest. Doing this plus normal file level backups would be a pretty safe DR solution. It also would cut down on the time a guest is down and eliminate the need for a shutdown/restart.
-----Original Message----- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Marcy Cortes Sent: Thursday, August 30, 2012 2:50 PM To: LINUX-390@VM.MARIST.EDU Subject: Re: LGR guest quiesce The suspend/resume thing exists already - http://www-03.ibm.com/support/techdocs/atsmastr.nsf/5cb5ed706d254a8186256c71 006d2e0a/57e3c8123412429186257910006ab443/$FILE/l0wadp00.pdf The CP STOP command may also be good enough. Yes, you could have lost data in open files, but this would be no different that say a loss of power. You'd fsck and go on when you booted back up. You wouldn't have the issue of disk A being out of sync with disk B which you'd get flashcopying a live system. Marcy -----Original Message----- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Scott Rohling Sent: Thursday, August 30, 2012 8:28 AM To: LINUX-390@VM.MARIST.EDU Subject: Re: [LINUX-390] LGR guest quiesce 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 <a...@bsc.gwu.edu> 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:LINUX-390@VM.MARIST.EDU] On Behalf Of > Rob van der Heij > Sent: Thursday, August 30, 2012 7:47 AM > To: LINUX-390@VM.MARIST.EDU > Subject: Re: LGR guest quiesce > > On 30 August 2012 11:43, Lu GL Gao <lu...@cn.ibm.com> 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 lists...@vm.marist.edu 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 lists...@vm.marist.edu 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 lists...@vm.marist.edu 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 lists...@vm.marist.edu 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 lists...@vm.marist.edu 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/
