On 2017-02-08 06:11 PM, Mario Lobo wrote: > On Tue, 7 Feb 2017 12:02:24 -0800 > Geoff Nordli <geo...@gnaa.net> wrote: > >> Hi Mario. >> >> I use the pause quite a bit to backup virtual machines. Pausing the >> machine will flush the cache and complete all outstanding async IO. >> >> https://www.virtualbox.org/pipermail/vbox-dev/2011-June/009810.html >> >> Look for the ignoreflush property and set that. >> >> VBoxManage setextradata "name" >> \ "VBoxInternal/Devices/ahci/0/LUN#[x]/Config/IgnoreFlush" >> >> As a note, I use iscsi targetsand zfs/solaris to host the data as >> zvols. >> >> Snapshots aren't 100% guaranteed. If you have applications like >> Exchangeconsider using something like VSS on Windows. For example, >> with Exchange I use VSS and then snapshot the disks from inside the >> the VM using putty/plink. Then I know I am getting a good copy of >> the data. >> >> Other applications may havereplication options. >> >> For things like SQL, I use a separate backup application to >> explicitly backup the database, just to make sure. >> >> >> Geoff >> >> >> >> On 2017-02-06 03:36 PM, Mario Lobo wrote: >>> Hi to all. >>> >>> Currently, my backup routine consists of shutting down all VMs, >>> copy all their .VDI files to the standby server, and restart the >>> VMs. >>> >>> The obvious reason is for the standby server to be ready to run the >>> VMs in case the primary server fails. >>> >>> A few questions comes to mind: >>> >>> 1) Shutting down and restarting the VMs is always a lot of work, no >>> to mention the loss of counters, system statistics, etc ... so, is >>> it safe just to pause the VMs to copy the .VDIs over? Would a >>> paused state .VDI start ok on the standby server if I need to fire >>> it up? >>> >>> 2) What is the proper procedure to backup via snapshots to a standby >>> machine that needs to be fully independent of the primary server? >>> >>> Any experiences or recommendations are gratefully welcomed. >>> >>> Thanks, >>> > Thanks for replying, Geoff! > > It made sense to me that pausing would be ok but I needed to confirm > this. > > One last question. > > Sounds wierd to me to set an IgnoreFlush property if pausing the > machine will flush the cache and complete all outstanding async IO. > > Is this setting telling the VM not to flush? > > Is this IgnoreFlush a per VM stting or general? > > Thanks again. >
Here is some more information on the ignoreflush property: https://unixsherpa.com/solution/honor-guest-idesata-flush-requests/ It is based on the device and it just tells vbox to not lie to the OS that data is has been saved to improve performance. I also disable caching in vbox on the controller. I do all my caching in zfs where I know the data is safe. Geoff ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ VBox-users-community mailing list VBox-users-community@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/vbox-users-community _______________________________________________ Unsubscribe: mailto:vbox-users-community-requ...@lists.sourceforge.net?subject=unsubscribe
