From: Michael <confabulate@kintzios.com>
To: gentoo-user@lists.gentoo.org
Subject: Re: [gentoo-user] virtualbox in headless configuration broken after update: delayed echo [ RESOLVED, kinda ]
Date: Thu, 18 Jun 2020 10:21:13 +0100 [thread overview]
Message-ID: <2028214.irdbgypaU6@lenovo.localdomain> (raw)
In-Reply-To: <99c8a40a-19b9-1837-85a9-4e405abfc8ad@iinet.net.au>
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On Thursday, 18 June 2020 00:09:45 BST William Kenworthy wrote:
> On 18/6/20 3:55 am, J. Roeleveld wrote:
> > On 17 June 2020 21:32:19 CEST, Michael <confabulate@kintzios.com> wrote:
> >> On Wednesday, 17 June 2020 18:31:42 BST J. Roeleveld wrote:
> >>> On 17 June 2020 19:01:54 CEST, Michael <confabulate@kintzios.com>
> >
> > This brings another problem I have with KVM/QEMU: all howtos and documents
> > I find show long commandline options to just start the VM. I have not
> > found one where I can provide all the config in a single file and use
> > that. Allowing me to duplicate settings by simply copying the file and
> > changing a few lines.
> >
> > KVM/Qemu seems to be written to be used together with virt-manager which,
> > for me, lacks important features to make it usable in production.
> >
> > --
> > Joost
>
> Until a few months ago I was using Qemu/KVM/VirtManager with snapshots
> for linux and Windows VM's running network services - the trick is
> redundancy and suspend.
>
> Using libvirt, suspend the VM which copies ram to disk, then snapshot
> ((I used btrfs) both the ram and storage and restart the VM - takes
> seconds (so redundancy may be needed) - at this point I backup'ed the
> snapshot and deleted it.
Ahh! Yes!
I had seen the Virsh command which involves pausing a live image and then
taking a snapshot of it. William's pointer makes sense.
However, there is also the option to define a memory file as an object
'-object memory-backend-file,size=1M,share,mem-path=/dev/shm/blah...'
and this can be attached/detached/migrated/snapshoted/etc between hosts as
desired.
More details here (search for "Generic object creation"):
https://qemu.readthedocs.io/en/latest/system/invocation.html
> When using snapshots of live systems, I had problems restoring some of
> the more active VM's which this avoids.
>
>
> BillK
Perhaps the technique with busy systems, other than pausing > snapshot, could
involve using a migration of the image to a new location? As I understand it
the newly migrated image will take over and start running in place of the old
image, the moment the migration is completed.
Scratching around I found the way to move an image from a qcow2 file on the
host fs, to a raw format on a disk/partition. It is simpler than I thought
(even with no libvirt):
qemu-img convert -O raw image.qcow2 /dev/sda5
Or,
the output can be 'image.raw' then keep a backup copy of it as a file and then
dd it to a partition.disk.
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prev parent reply other threads:[~2020-06-18 9:21 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-10 13:19 [gentoo-user] virtualbox in headless configuration broken after update: delayed echo n952162
2020-06-16 19:07 ` [gentoo-user] virtualbox in headless configuration broken after update: delayed echo [ RESOLVED, kinda ] n952162
2020-06-16 20:36 ` J. Roeleveld
2020-06-16 21:08 ` n952162
2020-06-17 4:48 ` J. Roeleveld
2020-06-17 5:42 ` n952162
2020-06-17 6:32 ` J. Roeleveld
2020-06-17 17:01 ` Michael
2020-06-17 17:31 ` J. Roeleveld
2020-06-17 19:32 ` Michael
2020-06-17 19:55 ` J. Roeleveld
2020-06-17 23:05 ` Michael
2020-06-17 23:09 ` William Kenworthy
2020-06-18 9:21 ` Michael [this message]
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