19
votes
Error creating snapshot: Operation not supported: internal snapshots of a VM with pflash based firmware are not supported
There is no fix for internal snapshots even in year 2022. The only solution would be to use external snapshots. For more details visit KVM: creating and reverting libvirt external snapshots. All ...
- 6,211
15
votes
ZFS on Linux send/receive resume on poor/bad ssh connection
You can use the -s option of zfs receive which will save a resumable token on the receiving side if the transfer fails. It depends if you are using netcat (nc) or SSH.
On the recv machine (netcat ...
- 251
13
votes
Accepted
Understanding how libvirt snapshots are stored
The xml files represents the snapshot metadata, if you open it you will see something like this (domain definition shortened for brevity):
your-snapshot.xml
<!--
WARNING: THIS IS AN AUTO-...
- 256
8
votes
Accepted
Practical limit on the number of btrfs snapshots?
While technically there is no limit on the number of snapshots, I asked on the BTRFS mailing list:
The (practical) answer depends to some extent on how you use btrfs.
Btrfs does have scaling ...
- 5,341
8
votes
Btrfs snapshot to non-btrfs disk. Encryption, read acess
I will just add to Gilles' answer by saying that although you may use “cp, rsync, etc.” to transfer your read-only subvolumes / snapshots, you may also send and store the subvolumes as btrfs streams ...
- 791
7
votes
Merge changes to upper filesystem to lower filesystem in Linux Overlay (OverlayFS) mount
I have found the overlayfs-tools project which implements a useful set of tools (diff, merge and vacuum). It requires the overlay to be unmounted so is an offline-only solution.
It is a good proof-of-...
- 621
7
votes
Accepted
Restore single files from a btrfs snapshot without doing a full copy
On Linux kernels older than 5.18 (specifically, commit 9f5710b), you could only use cp --reflink when the source and target were both on the same mount point. For this purpose, mounting the same ...
7
votes
Accepted
How to find the creation date/time of btrfs snapshots
You can use:
btrfs subvol show {path}
You can grep for Creation time.
- 1,349
7
votes
Accepted
Rollback root snapshot in BTRFS
What you have is a BTRFS filesystem with two subvolumes:
fedora - This is set as your default subvolume, and is what you see when you mount the filesystem without specifying specifying a subvolume. ...
- 7,278
7
votes
ZFS send/recv full snapshot
First you'll need to create an empty pool on Server A. zfs recv cannot create a new pool. So on Server A:
zpool create -R /mnt zfs49 [ mirror diskID1 diskID2 ]
... or some other VDEV structure of ...
- 8,322
6
votes
Accepted
btrfs revert snapshot of root FS
Your situation is somewhat simplified by the fact that neither your current nor desired subvolume is the "real" Btrfs root, that is, subvolume ID 0.
Start by (temporarily) mounting the real Btrfs ...
- 44.7k
6
votes
Accepted
Linux alternative to file history/shadow copies for internal backup?
The Windows 'Shadow Copy' aka 'Volume Shadow Copy Servce' does filesystem snapshotting. The Linux equivalent requires changing your filesystem/partitions, or possibly using 3rd party tools.
Options
...
- 3,700
6
votes
Accepted
Btrfs snapshot to non-btrfs disk. Encryption, read acess
A snapshot (in this sense) is a part of the filesystem. In btrfs terminology, it's a subvolume — it's one of the directory trees on the volume. It isn't in “archive form”. Making a snapshot of a ...
6
votes
Accepted
Never ending "Run configure hook of core snap if present"
According to this bug report comments snapd is failing if you install core and any snap at the same time.
To avoid the error you have to purge and reinstall snapd:
# apt purge snapd
# apt install ...
- 76
6
votes
Merge changes to upper filesystem to lower filesystem in Linux Overlay (OverlayFS) mount
An attempt at an online solution, but its not quite there.
The setup (in e.g. /tmp directory, as root):
LOWER=$HOME
mkdir u1 w1 o1 O
mount -t overlay overlay -o lowerdir=$LOWER,upperdir=u1,workdir=...
- 621
5
votes
Accepted
Can a user-defined "destroy-after" property be set on a ZFS snapshot?
Yes, you can.
# mark snapshot to destroy after 1 hour (3600 seconds)
zfs set :destroy-after=3600 tank@mysnap
# result of get operation will be just the value 3600
zfs get -Hpo value :destroy-after ...
- 1,312
5
votes
LVM snapshots vs. filesystem
Actually for the snapshot you use different LV.
There is quite reasonable howto:
https://www.tecmint.com/take-snapshot-of-logical-volume-and-restore-in-lvm/
- 9,832
5
votes
Practical limit on the number of btrfs snapshots?
You can have a combined total of 264 snapshots and subvolumes.
The btrfs design wiki page says (empahsis mine):
Subvolumes are basically a named btree that holds files and directories. They have ...
- 31.5k
5
votes
How to configure AppArmor so that KVM can start guest that has a backing file chain
It looks like it's related to AppArmor again (I had a similar issue some years ago on Ubuntu 14.04 that I forgot about). I was able to get it working by:
Installing apparmor-utils
sudo apt-get ...
- 2,279
5
votes
Accepted
how to snapshot thin provisioned lvm
ghv214-vg/Thin_LVM is a thin pool (the lower t attribute stands for thin pool), not a thin LV so you are trying to create a "normal" snapshot of a thin pool which requires size to be ...
- 18.9k
4
votes
Linux alternative to file history/shadow copies for internal backup?
Rsnapshot
http://rsnapshot.org/
Setup guide - https://wiki.archlinux.org/index.php/Rsnapshot
rsnapshot is a filesystem snapshot utility based on rsync. rsnapshot makes it easy to make periodic ...
- 3,150
4
votes
Accepted
Will writing identical data to blocks of a file under ZFS use space in snapshots?
Yes, ZFS will allocate extra space for the same file if a snapshot is taken from the fileset.
First let's create an empty fileset and prepare a file to copy from. For simplicity reasons, compression ...
- 6,462
4
votes
Accepted
Is it possible to use a file as Filesystem?
It possible to do something like fallocate -l 16G /lvm.fs, then format it as LVM, mount it and use it as storage pool for LXD? And of course, how can I do that if it is possible?
Start by making your ...
- 36.5k
3
votes
Merge changes to upper filesystem to lower filesystem in Linux Overlay (OverlayFS) mount
Another offline solution I've come up with is using rdiffdir to create a patch with the overlay mounted, then unmount and apply it. This solution requires the intermediate step of storing the patch ...
- 621
3
votes
LVM snapshots vs. filesystem
A Snapshot contains (some metadata and) copies of those (original i.e. from the moment of the snapshot creation) parts of the origin volume which have been writtem. Thus (except for the little ...
- 90.7k
3
votes
Accepted
Unable to zfs send | zfs receive datasets in same zpool
A kernel update recently occurred on the server (via CPanel) and the server hasn't been restarted. After reviewing log files I noticed that ZFS has been updated as well. I believe the commands in this ...
- 163
3
votes
Unable to zfs send | zfs receive datasets in same zpool
Several things are important here. Your errors stem from combinations of them:
Normally you send a specific snapshot or several snapshots instead of a whole file system. This means you do not need to ...
- 1,312
3
votes
ZFS on Linux snapshot recursively volume and subvolumes
According to man zfs:
-r Recursively create snapshots of all descendent datasets
So, zfs snapshot -r mypool/HOME@today will snapshot everything under mypool/HOME.
In your post, you use ...
- 719
3
votes
Accepted
Change btrfs default subvolume in order to delete snapshot
With mounting a BTRFS filesystem, it's possible to specify which subvolume to mount, or not:
A Btrfs filesystem has a default subvolume, which is initially set to
be the top-level subvolume [who'...
- 7,278
3
votes
Accepted
Difference in openjdk-6, openjdk-7, and openjdk-8 in terms of SLOC count?
If you look at the contents of the OpenJDK source packages, you’ll see that most of their source code is shipped inside tarballs inside the packages. If you run David A. Wheeler’s SLOCCount on the ...
- 450k
Only top scored, non community-wiki answers of a minimum length are eligible