@florent Can you please provide some summary on backup setup versus compression versus remotes configuration?

@frank-s This confirms my observations and tests that for compression to be active, data blocks must be enabled for remote.

@frank-s Do you have the "data block" option enabled for remote or not?

(The idea behind is to have both a compressed delta backup (the backup repository itself is backed up to another location via vpn, so the size of the backup matters) and the fastest possible restore option.)

In addition, I have verified that if the option "Store backup as multiple data blocks instead of a whole VHD file" is enabled, the restore from the data blocks structure takes about 2-3 longer than from the .vhd if this option is disabled (I tested the health check restore).

At least the first backup, i.e. the full backup (and maybe every key full backup milestone later) does not look like it is compressed. If the "Store backup as multiple data blocks instead of a whole VHD file" option is off, a .vhd of 116 GiB is stored, if it is on, the whole data block structure is only 67 GiB.

If I understand correctly, for compression to work for Incremental (Delta) backup, remote storage must have the option "Store backup as multiple data blocks instead of a whole VHD file" enabled, otherwise vhd files are stored without compression. Is that right?

@olivierlambert said in Compressed backups:

Compression is enabled by default for incremental backups.

Hi, if I configure Delta Backup and run a backup for the first time, a full backup of the affected virtual machines is performed. This initial full backup is also compressed?

@abudef said in Managing disks and storage in the XO GUI:

create a RAID 5

Or rather ZFS, but I guess it doesn't matter, it's more about the GUI management option in general...

Sure, for example I have 4 disks in my host server ready for local storage. I would like to list them in the GUI and create a RAID 5 from them, without having to connect to the host server console and use the mdadm tool. And I would like to select this RAID to create local storage again by selecting it without having to specify the device path.

Hi, I would like to ask if there is any plan for more advanced GUI support for managing local storage on individual hosts. I mean a comfortable management of disk devices, so that the preparation for mounting local storage does not have to be done in the command line with Linux tools, for example preparing and managing disks connected to a raid etc.

@olivierlambert So there are basically no dramatic architectural differences in the individual hypervisors in this regard?

@olivierlambert Well, I guess that too, but I meant something else, whether it might be somehow related to the architecture of individual hypervisors in general, whether simply the way Xen is built is a complication for implementing nested virtualization.

As I'm waiting there, I'm wondering why is implementing nested virtualization so difficult and lengthy in the case of Xen? VMware, H-V, VirtualBox, KVM - they all support it, so I wonder what the reasons might be that Xen still doesn't...

To pass the time during a long wait

Nested Virtualization (X86) Part I - George Dunlap, Xen Server:
https://www.youtube.com/watch?v=8jKGYY1Bi_o

Nested Virtualization (X86) Part II - George Dunlap, Xen Server:
https://www.youtube.com/watch?v=3MxWvVTmY1s

@planedrop In general, the fact is that the current XCP-ng 8.3 RC1 and XenServer 8 simply do not support any kind of nested virtualization. For example, when I want to try a mock setup of say 5 hypervisors, I just don't buy or dedicate 5 hw servers and rather make virtualized hypervisors. And for the record, I'm referring to the lab environment for debugging configurations and scenarios, not production.

P. S.: In more legacy Xen, which is part of XCP-ng 8.2, nested virtualization works.

P. P. S.: https://xcp-ng.org/forum/topic/8932/hardware-assisted-virtualization-is-not-enabled-on-this-host-even-though-platform-exp-nested-hvm-true-is-set

@olivierlambert Yeah, I used that of course, it looks like milliseconds, I just wanted to be sure because I couldn't track it down anywhere.

@olivierlambert said in Automatic startup and shutdows VMs at the specified time:

Very likely seconds

Could someone please try this? I set it to 120, aka 2 minutes, and the VM practically immediately went into force shutdown.

qemu-img convert disk_image_fixed.vhd -O vpc -o subformat=dynamic disk_image_dynamic.vhd

What units are used here? I can't find that information in the documentation