It seems that snapshots and instances are very similar (e.g. https://serverfault.com/questions/527449/why-does-openstack-distinguish-images-from-snapshots).
However, I've been unable to share snapshots publicly globally (i.e. across all projects). Note, I'm a user of the OpenStack installation, not an administrator of the installation.
Assuming that Images don't suffer the same limitation of Snapshots, is there a procedure for convert a snapshot to an image? If not, maybe I should ask a separate question, but my cloud admin tells me it needs to be an image.
for download
glance-image download
Initially I tried this:
openstack image save --file NixOS.qcow2 5426bbcf-06b3-42f3-b117-37395e7dde83
However, the reported size of NixOS.qcow2 was always 0 bytes. Not good. Well, the issue was apparently related to the fact that is is also what was reported in OpenStack and Horizon for the size of the Snapshot. So something weird was going on, but functionally, I could still use the snapshot to create instances without issue.
I then created a volume of a snapshot in horizon (when shut off, couldn't create a volume when shelved), then used this command to create an image from the newly created volume (NixSnapVol):
openstack image create --volume NixSnapVol NixSnapVol-img
Interestingly the reported size went from 41GB to 45GB, maybe that was part of the issue. Anyway, seems to work now, and bonus is that it is now RAW type instead of qcow2, so I don't need to do the conversion (our system largely benefits from using RAW as we have a ceph backend).
Related
I am working on a task to be able to backup VM image volumes in another server and location, the problem is, I don't want to copy the whole image file each time I want to start a backup job, I want to backup the whole image only once and then backup incrementally each time I want to do a backup from a vm.
Is there anyway to do that? I don't want to use snapshots because when the number of snapshots increases, it will have an impact on volume performance.
If there is another way or if there is a way to use snapshots more efficient, please tell me.
I have tried volume snapshot locally, I want to know how to do it externally or any other sufficient ways to do incremental external backups.
ive been working on a project allowing you to create full and incremental or differential backups of libvirt/kvm based virtual machines. It works by using the latest features provided by the libvirt and qemu projects (changed block tracking). So if the libvirt/qemu versions you are using are supporting the features, you might want to give it a try:
https://github.com/abbbi/virtnbdbackup
I'm working with a Python-based library called "datasette" that makes it easy to search SQLite databases. I'm trying to push more than 1.5GB worth of SQLite databases, 535MB compressed, to Heroku but I get this error when I run datasette publish heroku.
Compiled slug size: 535.5M is too large (max is 500M).
How can I work around the slug size limits?
There is no way to get around Heroku's slug size limits, and there doesn't appear to be any way to use Datasette with a client-server database.
Either reduce the amount of data you're trying to ship or find another host.
Google Cloud Run is a very inexpensive alternative to Heroku which doesn't have size limits. You can use it with Datasette like this: https://datasette.readthedocs.io/en/stable/publish.html#publishing-to-google-cloud-run
I'm working on a projet on OpenStack. I have installed OpenStack by creating two virtual machines, one for the controller node and the other for the compute node.
Actually, I want to test an example of live migration on openstack and I have found a video which describes the aproch. As the video shows, I need to have 2 compute nodes, and I want to know if I just need to create a second compute node or this second compute should be created at the phase of installation of openstack.
This is the link of the video that I have watched: https://www.youtube.com/watch?v=_4vJUYFGbEM
Thank you
It doesn't matter when you add the compute nodes (During the install or later on). Please also remember that the live-migration piggy backs on the hypervisor. So depending on hypervisor that one uses, this may or may not be possible.
Please look at this http://docs.openstack.org/admin-guide/compute-configuring-migrations.html#section-configuring-compute-migrations to ensure that the migration capability exists
It simply boils down to a few things
The storage is not moved in case of a live migration, so if you have a VM with instance storage, you will need to have a shared file system like NFS or something, If you have an instance backed by a cinder volume you will be able do the migration without the shared storage.
The Nova-Compute application needs to be installed on the destiantion
The hypervisor version should be the same.
I hope this clarifies.
Either works. OpenStack allows you dynamically add and remove computes nodes from a cloud environment.
Please refer to http://docs.openstack.org/admin-guide/compute-configuring-migrations.html for extra details.
Live migration for light instances can be done over network ,without shared storage, but for heavy instances ,shared storage or shared volume will be preferred. As you mentioned you have two compute nodes ,theirs nova storage should be shared storage.
Long answer short in my perspective,
You can add/remove compute node at any time from an OpenStack installation.
For adding compute, follow installation guide to add new compute node right from environment setup.
Also, dont forget to install networking part in your new Compute node.
I'm running several VMs within Xen, and now I'm trying to create/revert snapshots of my VMs.
Along with Xen and blktap2, another utility, vhd-util is also delivered, and according to its description, I guess I can use it to create/revert VM snapshots.
To create a snapshot is actually easy, I just call:
vhd-util snapshot -n aSnapShot.vhd -p theVMtoBackup.vhd
But when it comes to reverting a snapshot, things get really annoying.
The "revert" command requires a mandatory argument "journal", like this:
vhd-util revert -n aSnapShot.vhd -j someThingCalledJournalOfWhichIHaveNoIdea
And vhd-util expects some info from the journal, which means it's not some empty file you can write logs in.
But I've went through the code and the internet, still get no idea where this Journal comes from.
Similar question is asked
http://xen.1045712.n5.nabble.com/snapshots-with-vhd-util-blktap2-td4639476.html but poor guy never get answered.
Hope someone here could help me out.
Creating snapshots in VHD works by putting an overlay over the existing VHD image, so that any change get written into the overlay file instead of overwriting existing data. For reading the top-most data is returned: either the data from the overlay if that sector/cluster was already over-written, or from the original VHD file if it was not-yet over-written.
The vhd-util command creates such an overlay-VHD-file, which uses the existing VHD image as its so-called "backing-file". It is important to remember, that the backing-file must never be changed while snapshots still using this backing-file exist. Otherwise the data would change in all those snapshots as well (unless the data was overwritten there already.)
The process of using backing files can be repeated multiple times, which leads to a chain of VHD files. Only the top-most file should ever be written to, all other files should be handled as immutable.
Reverting back to a snapshot is as easy as deleting the current top-most overlay file and creating a new empty overlay file again, which again expose the data from the backing file containing the snapshot. This is done by using the same command again as above mentioned. This preserves your current snapshot and allows you to repeat that process multiple times.
(renaming the file would be more like "revert back to and delete last snapshot".)
Warning: before re-creating the snapshot file, make sure that no other snapshots exists, which uses this (intermediate) VHD file as its backing file. Otherwise you would not only loose this snapshot, but all other snapshots depending on this one.
You don't need to use revert, all you need to do is shut down the VM, rename aSnapShot.vhd to theVMtoBackup.vhd and restart the VM.
I'm using alfresco throw cmis.
On one of our environment, we have an issue.
We want to create a folder and put some docs in it.
This works fines in all our env except one.
In this one, we can create the folder.
But when we do a search to find the folder, the folder isn't found.
After that i can find it with the share gui.
I have no error message in the share app.
Does any one have an idea on what could be the issue?
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When using Alfresco with SOLR, you need to be aware that the SOLR index isn't quite real-time. Close to real time, sure, but it's asynchronous so there's always a lag. (It's an eventually consistent index, not a fully realtime one)
There's a lot of information on the Alfresco and SOLR Wiki, including the way you can query what the current lag is.
If the lag is very low (eg a lightly loaded system), you can find that SOLR will catch up almost instantly, and newly created items will show instantly in the search results. However, it's more normal to expect to have to wait a little bit, especially on more loaded systems.
If no new results are showing up even after several minutes, you'll want to follow the instructions on the wiki or the SOLR Monitoring and Troubleshooting docs to work out why and fix.