hello all, I have little experience of virtualisation only what i have read in the past couple of days! but i think it can offer me what i need. I would be grateful for your input. I have 3 systems I need to demo, I want to deploy these systems to a base state where i know that they will be working. At this point I want to lock them. I want to be able to give it at this point to somebody and say "do want you want" when/if they break it i want to be able to return it to its known stable state. This return to a stable state needs to happen quickly, seconds would be great but minutes would be acceptable. I have been reading about differencing disks and believe that these would be the right solution? thanks Alex _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Friday 09 July 2010 09:29:09 Alex Edwards wrote:> hello all, > > I have little experience of virtualisation only what i have read in the > past couple of days! but i think it can offer me what i need. I would be > grateful for your input. > > I have 3 systems I need to demo, I want to deploy these systems to a base > state where i know that they will be working. At this point I want to lock > them. I want to be able to give it at this point to somebody and say "do > want you want" when/if they break it i want to be able to return it to its > known stable state. This return to a stable state needs to happen quickly, > seconds would be great but minutes would be acceptable. > > I have been reading about differencing disks and believe that these would > be the right solution? > > thanks > Alex >I believe that is a sort of snapshotting you are referring to; AFAIK Xen does not have such a feature, but LVM does. You need to install your root file system on LVM as well, don''t know what the effect would be of restoring a root file system snapshot however. Also don''t know if this can be done in "seconds" - you need to try this I think. Another way could be to make a RAID1, disconnect it after your initial install, then after changes swap the main disk and mirror it again to the first one to get to the original state. This answers the "in seconds" part. B. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Fri, Jul 9, 2010 at 2:29 PM, Alex Edwards <edwards.alex@gmail.com> wrote:> I have 3 systems I need to demo, I want to deploy these systems to a base > state where i know that they will be working. At this point I want to lock > them. I want to be able to give it at this point to somebody and say "do > want you want" when/if they break it i want to be able to return it to its > known stable state. This return to a stable state needs to happen quickly, > seconds would be great but minutes would be acceptable. > > I have been reading about differencing disks and believe that these would be > the right solution?Sort of, though I''m not sure if the term "differencing disk" is often used in Xen. In Xen (the open source hypervisor), when using Linux dom0, you could use LVM snapshot like Bart mentioned. This is Linux LVM feature, not Xen-specific feature. IMHO it''s kinda tricky to use though, since it uses somewhat different concept (e.g. "rollback" might not be easy). Xen 4 internally has support for qcow and VHD (http://lxr.xensource.com/lxr/source/tools/blktap2/README). Hopefully others can share their experience using it. There''s also XCP 0.5 (http://blog.xen.org/index.php/2010/07/07/xen-cloud-platform-0-5-released/) with live VM snapshots & checkpoints feature, which you might want to look at (although I haven''t used it personally). If you''re feeling "adventurous", you might want to also check out storage-based snapshot/rollback/clone with zfs, which is possible using - freebsd/opensolaris dom0 (dom0 support might not be as good as Linux dom0) - linux dom0, with zfs-fuse If you''re new to virtualization, and use it primarily on laptop for testing/demo, I''d actually suggest you do not use Xen, and rather use virtualbox/vmware. Also note that whatever method you use to provide snapshot/rollback capability, it will incure some kind of overhead (which can be significant), so be sure to test it first. -- Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
---------- Forwarded message ---------- From: Alex Edwards <edwards.alex@gmail.com> Date: Fri, Jul 9, 2010 at 9:40 AM Subject: Re: [Xen-users] differencing disks To: Bart Coninckx <bart.coninckx@telenet.be> yes I do believe that it is snapshoting, Differencing disks appears to be a msoft term given to their VHD tech. I could use snapshots but its more than I need. I want 1 point that i always go back to. Could I create a system image that can just be remounted when I want to go back? If i had an image of my system at a point in time, how fast could I remount it in a different VM? thanks Alex On Fri, Jul 9, 2010 at 9:03 AM, Bart Coninckx <bart.coninckx@telenet.be>wrote:> On Friday 09 July 2010 09:29:09 Alex Edwards wrote: > > hello all, > > > > I have little experience of virtualisation only what i have read in the > > past couple of days! but i think it can offer me what i need. I would be > > grateful for your input. > > > > I have 3 systems I need to demo, I want to deploy these systems to a base > > state where i know that they will be working. At this point I want to > lock > > them. I want to be able to give it at this point to somebody and say "do > > want you want" when/if they break it i want to be able to return it to > its > > known stable state. This return to a stable state needs to happen > quickly, > > seconds would be great but minutes would be acceptable. > > > > I have been reading about differencing disks and believe that these would > > be the right solution? > > > > thanks > > Alex > > > > I believe that is a sort of snapshotting you are referring to; AFAIK Xen > does > not have such a feature, but LVM does. You need to install your root file > system on LVM as well, don''t know what the effect would be of restoring a > root > file system snapshot however. Also don''t know if this can be done in > "seconds" > - you need to try this I think. Another way could be to make a RAID1, > disconnect it after your initial install, then after changes swap the main > disk and mirror it again to the first one to get to the original state. > This > answers the "in seconds" part. > > B. >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> > hello all, > > I have little experience of virtualisation only what i have read inthe past> couple of days! but i think it can offer me what i need. I would begrateful> for your input. > > I have 3 systems I need to demo, I want to deploy these systems to abase> state where i know that they will be working. At this point I want tolock> them. I want to be able to give it at this point to somebody and say"do want> you want" when/if they break it i want to be able to return it to itsknown> stable state. This return to a stable state needs to happen quickly,seconds> would be great but minutes would be acceptable. > > I have been reading about differencing disks and believe that thesewould be> the right solution? >Is it DomU systems you want to do this with, or the whole physical machine? If DomU''s, are they Windows or Linux? Windows has Microsoft SteadyState so you wouldn''t need to even involve Xen in doing this, and the user could control if their changes are written back to the ''base'' or not at shutdown time. I''m sure Linux has CoW (Copy on Write) filesystems which would also allow you to do this without involving Xen too, which is probably best if you are just learning. Is there no such thing as a ''snapshot'' block device handler? Eg ''snap:vg-xen/lv-linux-domu-base'' which would create a snapshot of the lv (maybe using domid to make the snapshot name unique). That would be really useful! James _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Friday 09 July 2010 10:42:41 Alex Edwards wrote:> ---------- Forwarded message ---------- > From: Alex Edwards <edwards.alex@gmail.com> > Date: Fri, Jul 9, 2010 at 9:40 AM > Subject: Re: [Xen-users] differencing disks > To: Bart Coninckx <bart.coninckx@telenet.be> > > > yes I do believe that it is snapshoting, Differencing disks appears to be a > msoft term given to their VHD tech. I could use snapshots but its more than > I need. I want 1 point that i always go back to. Could I create a system > image that can just be remounted when I want to go back? If i had an image > of my system at a point in time, how fast could I remount it in a different > VM? > > thanks > Alex > > On Fri, Jul 9, 2010 at 9:03 AM, Bart Coninckx<bart.coninckx@telenet.be>wrote:> > On Friday 09 July 2010 09:29:09 Alex Edwards wrote: > > > hello all, > > > > > > I have little experience of virtualisation only what i have read in the > > > past couple of days! but i think it can offer me what i need. I would > > > be grateful for your input. > > > > > > I have 3 systems I need to demo, I want to deploy these systems to a > > > base state where i know that they will be working. At this point I want > > > to > > > > lock > > > > > them. I want to be able to give it at this point to somebody and say > > > "do want you want" when/if they break it i want to be able to return it > > > to > > > > its > > > > > known stable state. This return to a stable state needs to happen > > > > quickly, > > > > > seconds would be great but minutes would be acceptable. > > > > > > I have been reading about differencing disks and believe that these > > > would be the right solution? > > > > > > thanks > > > Alex > > > > I believe that is a sort of snapshotting you are referring to; AFAIK Xen > > does > > not have such a feature, but LVM does. You need to install your root file > > system on LVM as well, don''t know what the effect would be of restoring a > > root > > file system snapshot however. Also don''t know if this can be done in > > "seconds" > > - you need to try this I think. Another way could be to make a RAID1, > > disconnect it after your initial install, then after changes swap the > > main disk and mirror it again to the first one to get to the original > > state. This > > answers the "in seconds" part. > > > > B. >Forget about my remark about the root file system and the RAID1, was thinking of a physical machine. For Xen, I would do it like this: - create a master image file - copy this to in three versions: orginal.img, running1.img and running2.img - boot the Xen machine with running1.img, have people change stuff - stop the Xen machine, change the image file in the Xen config to running2.img - start the machine again - copy orginal.img to running1.img - stop the machine, change config to running1.img - copy orginal.img to running2.img - repeat ... scripted this will only take you seconds. It does suppose however that the guests are running long anough to have the original image copied in background. B. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Yeah thanks Bart thats what im after. Would i be potentially be able to run running1.img and running2.img at the same time? And i can build something in that will prevent it from trying to start an img thats being copied but i dont forsee it being that unstable that it breaks that often. thankyou very much Alex On Fri, Jul 9, 2010 at 10:57 AM, Bart Coninckx <bart.coninckx@telenet.be>wrote:> On Friday 09 July 2010 10:42:41 Alex Edwards wrote: > > ---------- Forwarded message ---------- > > From: Alex Edwards <edwards.alex@gmail.com> > > Date: Fri, Jul 9, 2010 at 9:40 AM > > Subject: Re: [Xen-users] differencing disks > > To: Bart Coninckx <bart.coninckx@telenet.be> > > > > > > yes I do believe that it is snapshoting, Differencing disks appears to be > a > > msoft term given to their VHD tech. I could use snapshots but its more > than > > I need. I want 1 point that i always go back to. Could I create a system > > image that can just be remounted when I want to go back? If i had an > image > > of my system at a point in time, how fast could I remount it in a > different > > VM? > > > > thanks > > Alex > > > > On Fri, Jul 9, 2010 at 9:03 AM, Bart Coninckx > <bart.coninckx@telenet.be>wrote: > > > On Friday 09 July 2010 09:29:09 Alex Edwards wrote: > > > > hello all, > > > > > > > > I have little experience of virtualisation only what i have read in > the > > > > past couple of days! but i think it can offer me what i need. I > would > > > > be grateful for your input. > > > > > > > > I have 3 systems I need to demo, I want to deploy these systems to a > > > > base state where i know that they will be working. At this point I > want > > > > to > > > > > > lock > > > > > > > them. I want to be able to give it at this point to somebody and say > > > > "do want you want" when/if they break it i want to be able to return > it > > > > to > > > > > > its > > > > > > > known stable state. This return to a stable state needs to happen > > > > > > quickly, > > > > > > > seconds would be great but minutes would be acceptable. > > > > > > > > I have been reading about differencing disks and believe that these > > > > would be the right solution? > > > > > > > > thanks > > > > Alex > > > > > > I believe that is a sort of snapshotting you are referring to; AFAIK > Xen > > > does > > > not have such a feature, but LVM does. You need to install your root > file > > > system on LVM as well, don''t know what the effect would be of restoring > a > > > root > > > file system snapshot however. Also don''t know if this can be done in > > > "seconds" > > > - you need to try this I think. Another way could be to make a RAID1, > > > disconnect it after your initial install, then after changes swap the > > > main disk and mirror it again to the first one to get to the original > > > state. This > > > answers the "in seconds" part. > > > > > > B. > > > > Forget about my remark about the root file system and the RAID1, was > thinking > of a physical machine. For Xen, I would do it like this: > > - create a master image file > - copy this to in three versions: orginal.img, running1.img and > running2.img > - boot the Xen machine with running1.img, have people change stuff > - stop the Xen machine, change the image file in the Xen config to > running2.img > - start the machine again > - copy orginal.img to running1.img > - stop the machine, change config to running1.img > - copy orginal.img to running2.img > - repeat ... > > scripted this will only take you seconds. It does suppose however that the > guests are running long anough to have the original image copied in > background. > > B. > >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Friday 09 July 2010 12:05:30 Alex Edwards wrote:> Yeah thanks Bart thats what im after. Would i be potentially be able to run > running1.img and running2.img at the same time? And i can build something > in that will prevent it from trying to start an img thats being copied but > i dont forsee it being that unstable that it breaks that often. > > thankyou very much > Alex > > On Fri, Jul 9, 2010 at 10:57 AM, Bart Coninckx<bart.coninckx@telenet.be>wrote:> > On Friday 09 July 2010 10:42:41 Alex Edwards wrote: > > > ---------- Forwarded message ---------- > > > From: Alex Edwards <edwards.alex@gmail.com> > > > Date: Fri, Jul 9, 2010 at 9:40 AM > > > Subject: Re: [Xen-users] differencing disks > > > To: Bart Coninckx <bart.coninckx@telenet.be> > > > > > > > > > yes I do believe that it is snapshoting, Differencing disks appears to > > > be > > > > a > > > > > msoft term given to their VHD tech. I could use snapshots but its more > > > > than > > > > > I need. I want 1 point that i always go back to. Could I create a > > > system image that can just be remounted when I want to go back? If i > > > had an > > > > image > > > > > of my system at a point in time, how fast could I remount it in a > > > > different > > > > > VM? > > > > > > thanks > > > Alex > > > > > > On Fri, Jul 9, 2010 at 9:03 AM, Bart Coninckx > > > > <bart.coninckx@telenet.be>wrote: > > > > On Friday 09 July 2010 09:29:09 Alex Edwards wrote: > > > > > hello all, > > > > > > > > > > I have little experience of virtualisation only what i have read in > > > > the > > > > > > > past couple of days! but i think it can offer me what i need. I > > > > would > > > > > > > be grateful for your input. > > > > > > > > > > I have 3 systems I need to demo, I want to deploy these systems to > > > > > a base state where i know that they will be working. At this point > > > > > I > > > > want > > > > > > > to > > > > > > > > lock > > > > > > > > > them. I want to be able to give it at this point to somebody and > > > > > say "do want you want" when/if they break it i want to be able to > > > > > return > > > > it > > > > > > > to > > > > > > > > its > > > > > > > > > known stable state. This return to a stable state needs to happen > > > > > > > > quickly, > > > > > > > > > seconds would be great but minutes would be acceptable. > > > > > > > > > > I have been reading about differencing disks and believe that these > > > > > would be the right solution? > > > > > > > > > > thanks > > > > > Alex > > > > > > > > I believe that is a sort of snapshotting you are referring to; AFAIK > > > > Xen > > > > > > does > > > > not have such a feature, but LVM does. You need to install your root > > > > file > > > > > > system on LVM as well, don''t know what the effect would be of > > > > restoring > > > > a > > > > > > root > > > > file system snapshot however. Also don''t know if this can be done in > > > > "seconds" > > > > - you need to try this I think. Another way could be to make a RAID1, > > > > disconnect it after your initial install, then after changes swap the > > > > main disk and mirror it again to the first one to get to the original > > > > state. This > > > > answers the "in seconds" part. > > > > > > > > B. > > > > Forget about my remark about the root file system and the RAID1, was > > thinking > > of a physical machine. For Xen, I would do it like this: > > > > - create a master image file > > - copy this to in three versions: orginal.img, running1.img and > > running2.img > > - boot the Xen machine with running1.img, have people change stuff > > - stop the Xen machine, change the image file in the Xen config to > > running2.img > > - start the machine again > > - copy orginal.img to running1.img > > - stop the machine, change config to running1.img > > - copy orginal.img to running2.img > > - repeat ... > > > > scripted this will only take you seconds. It does suppose however that > > the guests are running long anough to have the original image copied in > > background. > > > > B. >Well you can''t copy and use an image file at the same time obviously. If you are running several guests at the same time, you just need to repeat this procedure per guest. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> > If you''re new to virtualization, and use it primarily on laptop for > testing/demo, I''d actually suggest you do not use Xen, and rather use > virtualbox/vmware. Also note that whatever method you use to provide > snapshot/rollback capability, it will incure some kind of overhead > (which can be significant), so be sure to test it first. > > -- > Fajar > >Agreed. Virtualbox has snapshotting built in and works well once you understand their crazy terminology. There are a lot of complaints in the VirtualBox forums about snapshotting not being straight forward but it does work. I had to set up a VM, then try different things to figure out what does exactly what but once I had it figured out then I used it a lot. Grant McWilliams Some people, when confronted with a problem, think "I know, I''ll use Windows." Now they have two problems. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Friday 09 July 2010 15:58:06 Grant McWilliams wrote:> > If you''re new to virtualization, and use it primarily on laptop for > > testing/demo, I''d actually suggest you do not use Xen, and rather use > > virtualbox/vmware. Also note that whatever method you use to provide > > snapshot/rollback capability, it will incure some kind of overhead > > (which can be significant), so be sure to test it first. > > > > -- > > Fajar > > Agreed. Virtualbox has snapshotting built in and works well once you > understand their crazy terminology. > There are a lot of complaints in the VirtualBox forums about snapshotting > not being straight forward but it does work. > I had to set up a VM, then try different things to figure out what does > exactly what but once I had it figured out then I used > it a lot. > > > > Grant McWilliams > > Some people, when confronted with a problem, think "I know, I''ll use > Windows." > Now they have two problems. >The same goes for VMware Server 2. No idea which is better, have no experience with Virtualbox. B. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users