A snapshot is a copy of data taken at a specific point in time.

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21
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4answers
3k views

LVM snapshots vs. file system snapshots

As far as I know, LVM makes it possible to take snapshots of a volume. There are also a number of file systems (ZFS, Btrfs, reiserfs, ...) which supports snapshots. However, I've never understood the ...
20
votes
5answers
6k views

Why are snapshots considered as temporary backups not real backups?

I am using VMware ESXi. In our team we use to provide snapshots for long term backup. Then we faced issues like memory spillover and the server got hang up. I started reading in VMware knowledgebase ...
15
votes
2answers
5k views

Safe to Use an Amazon EBS Volume While Snapshot in Progress?

Is it safe to use an EBS volumne while a snapshot is being created? I've currently got a 100Gb EBS volume mounted. I am in the process of snapshotting it. Goodness it's slow!! It's going to end up ...
14
votes
8answers
2k views

Do snapshots + RAID count as a good on-site backup solution?

The two main reasons I can think of for taking backups seems to be taken care of when I use both snapshots and RAID together with btrfs. (By RAID here, I mean RAID1 or 10) Accidental deletion of ...
11
votes
4answers
21k views

Is this how LVM snapshots work?

I'm trying to figure out how LVM snapshots work so I can implement it on my fileserver but I'm having difficulty finding anything on google that explains how it works instead of how to use it for a ...
11
votes
4answers
5k views

Why VM snapshots are affecting performance?

I read in one of the VMware KB article says that snapshots will directly proportional to VM performance. But my team keep asking me how snapshots can affect performance. I would like to give them ...
11
votes
11answers
6k views

Best compression for ZFS send/recv

I'm sending incremental ZFS snapshots over a point-to-point T1 line and we're to a point where a day's worth of snapshots can barely make it over the wire before the next backup starts. Our send/recv ...
10
votes
3answers
13k views

Snapshot/rollback for libvirt+KVM?

I've recently begun using KVM for my development/test environment on a Linux host system with 8G memory. Prior, I was using VMware Fusion for my virtual environment, but my Macbook only has 2G memory. ...
10
votes
3answers
14k views

How to make/compare filesystem/registry snapshots in Windows?

What's a simple way to get a list of all files installed/modified and keys added/removed by a Windows (XP, Vista or 7) program installer? I'd like to take a before and after snapshot, and see what ...
10
votes
2answers
489 views

Why are all of my ZFS snapshot directories empty?

I'm running an Oracle 11 box as a ZFS storage appliance, and I'm taking regular snapshots of the ZFS filesystems, via cron. In the past, I know that if I wanted to grab a particular file from a ...
9
votes
4answers
10k views

Linux LVM snapshot commit or revert?

I'm about to perform an experimental upgrade on my CentOS 5 server. If the upgrade fails, I want to be able to back out the changes to the filesystem. This scenario seems similar to the example in ...
9
votes
3answers
950 views

Can NetApp Snapshots be used as Backups?

Our shop relies very heavily on NetApp Volume Snapshots for backups. We use traditional agent-based tape backups for some of our data but by and large we rely on the Snapshots for the majority of our ...
8
votes
2answers
9k views

What happens to children when deleting a snapshot in vmware?

I'm new to virtualization and want to make sure I understand what will happen when I delete a snapshot Say I have a tree like this Base SnapshotA SnapshotB SnapshotC Two questions: If I ...
7
votes
5answers
5k views

How to delete all but last [n] ZFS snapshots?

I'm currently snapshotting my ZFS-based NAS nightly and weekly, a process that has saved my ass a few times. However, while the creation of the snapshot is automatic (from cron), the deletion of old ...
7
votes
3answers
2k views

Backing up VirtualBox VMs

Does anyone have a good complete strategy for backing up a bunch of virtual machines running under VirtualBox? I intend to run a handful of virtual machines on a single hardware platform and back ...
7
votes
2answers
513 views

Does speed of ZFS snapshot rollback depend on number of files?

I have tested a 10Gbit connection between two hosts to be able to read a 10GB file from host1 and write it to host2 using netcat, where the speed was 410MB/s. When I ZFS send/receive again with ...
7
votes
3answers
6k views

vmware esxi 5, cant create snapshots and consolidate fails, how to delete old or consolidate redo logs?

I have a VM that seems to be working ok, but when VMWare DR (or I) tries to create a snap shot, it fails, and when I view the summary page of the VM it has a warning at the top showing that the disks ...
6
votes
2answers
540 views

What does zfs receive -F do?

When I read man zfs for zfs receive I see -F Force a rollback of the file system to the most recent snap- shot before performing the receive operation. If receiving an ...
6
votes
2answers
266 views

VMWare/ESX Snapshots vs Libvirt snapshots vs LVM2 snapshots

In VMWare, when a snapshot is taken, my understanding is that it creates delta disks, and any writes that occur after the snapshot is created will be written to these new delta disk images, and not ...
6
votes
2answers
928 views

Large number of snapshots on a ZFS system

Here's my scenario: I have two servers (well many more, but two for this scenario), one is a Solaris backup server, the second is a CentOS Linux Server. Every night the CentOS server runs a cron job ...
5
votes
10answers
455 views

VMWare Snapshots

Is it a good idea to take snapshots of production servers at regular intervals. I am reading a lot of website that suggest that you should not take snapshots of production systems, stating that it ...
5
votes
4answers
2k views

How to keep or drop LVM snapshot?

I have made an LVM snapshop by lvcreate --name snap --size 10G -s /dev/vg00/vm What command should I write if I want to drop the snapshot, and not keep the changes that have happened since the ...
5
votes
3answers
715 views

Which filesystems offer snapshot functionality for users to recover data?

I'm working on a project that will teach linux to youth. Knowing they will have a tendency to delete or corrupt items in their home directories we are looking for a good snapshot option. We will not ...
5
votes
2answers
394 views

What are the tradeoffs between using hypervisor- vs. storage-array-based snapshots as backup sources?

Suppose you have some virtual machines (running in eg. ESXi) that are stored on an iSCSI storage array (eg. EqualLogic PS4110). Now suppose you want to set up a backup and restore regime that looks ...
4
votes
5answers
8k views

How do I delete ESXi vm snapshots using the least additional space possible?

We have a tree of about 15 snapshots of a virtual machine that runs Win2k8, as you may guessed our datastore is soon to run out of space. My objective is to delete all the snapshots, as it seems it ...
4
votes
3answers
289 views

Is there a reason(s) I should not create a datastore to house a single VM?

I was at a Dell EqualLogic training event and the speaker threw out the idea that it may not be a bad idea to create a single datastore to house a single VM rather than making a large datastore and ...
4
votes
4answers
1k views

How to have ZFS make snapshots of a directory only when files are changed?

Is it possible to have ZFS make snapshots of a filesystem i.e. pool/filesystem/ only when files are changed? Instead of using cron or something to automatically create a snapshot every 5 minutes is it ...
4
votes
2answers
3k views

After restoring a HyperV snapshot, I get “the trust relationship between this workstation and the primary domain failed”

I have a Windows Server 2008 R2 HyperV machine. I had to restore it to an old snapshot, and now I'm getting the following error when logging in through remote desktop using a domain ID: "the trust ...
4
votes
2answers
1k views

Correct process for starting new EC2 Instance from an EBS snapshot

I have an EC2 instance running the Ubuntu 12.04 32bit AMI (available in the first page the Classic wizard for launching a new instance). The root device is an EBS volume. I then follow these steps: ...
4
votes
1answer
5k views

Robocopy, do not overwrite existing files, but copy the changed / new ones

Is it possible to mirror the two directories without overwritting the files in destination directory with new/changed/deleted files. Something like snapshots. Example: Copy the source directory with ...
4
votes
1answer
222 views

MongoDB Disaster Prep on AWS

I'm looking for best practice advice covering MongoDB disaster recovery within an AWS hosted environment. Our setup is fairly standard at this point, replica set of 3 servers (1 primary, 1 secondary, ...
4
votes
2answers
1k views

Amazon EC2: Restoring Windows EBS snapshots into AMIs or Instances?

As my Windows EC2 instance lives, starting and stopping many times a week, it evolves. These changes get saved to it's EBS volume, so state is persistent across reboots. Now, periodically I backup ...
4
votes
2answers
3k views

Is it possible to convert a LVM2 snapshot to a linear LV?

We have DRBD volumes that are presented to guests, and we often snapshot them with the intention of reverting back to the snapshots. I understand in LVM, snapshoting then working with the snapshot is ...
4
votes
0answers
41 views

Proper way of handling LXC containers on btrfs

Lets say we have one server with lxc installed, and a lxc container used for as a base img /var/lib/lxc/ubuntu_base. For simplicity let's forget the config changes after copying the base img. some ...
3
votes
4answers
2k views

Handling XenServer snapshotting and cloning with ZFS SAN

I'm planning on setting up a XenServer machine that uses a NexentaOS/ZFS-based SAN for storage of the Virtual Disk Images (VDIs) through iSCSI. I know I could just setup a big Storage Repository (SR) ...
3
votes
5answers
1k views

Backup solution for 10TB using ubuntu

I am setting up a backup server with roughly ten 2TB hard drives raided. The purpose of this machine is simply to back up about 3-10TB of data from another server. What is the best way to achieve ...
3
votes
3answers
609 views

How to take snapshot of the filesystem in linux (files, their sizes only, not their data)

We need to take a snapshot of your linux server. We don't want to backup the data, just a snapshot we can compare against changes.
3
votes
2answers
2k views

Is it possible to create an EBS AMI for windows EC2 instance?

We have a Windows server (EBS backed) running in EC2. We make regular snapshots for data backups. I'd like to create a new EC2 instance from one of these snapshots. Yes, I realise this is the same as ...
3
votes
2answers
437 views

ext3 Snapshot Support

Does the ext3 filesystem support snapshotting? If so, is can this be done with straight partitions with no LVM? An example of "straight partitions" would be the following: /dev/sda1 /boot ext3 ...
3
votes
2answers
881 views

Checking for orphaned snapshots - ESXi5

So we had some issues with our passive mail node over the weekend doing vmtools updates and to resolve a problem we had to revert to a snapshot and then reseed all the databases across. All in all ...
3
votes
2answers
287 views

open source backup system with user-driven recovery

At my old company we used NetApp, which supported a ".snapshot" feature. Whenever I did something stupid to my files, I could cd .snapshot and find hourly and nightly directories which contain ...
3
votes
2answers
2k views

How to export a specific virtualbox snapshot as a raw disk image

I created a Linux appliance for my friends. It's a small Ubuntu installation with Trac, lighthttp and ufw configured. I made it using VirtualBox. Now I want to export the latest snapshot version ...
3
votes
3answers
777 views

Immutable hard links on ext3/4?

In my research on file versioning at the fs level, snapshotting, and related ideas, I took a look at hard-links and exactly what they are and how they behave. Using rsync you can get a pretty slick ...
3
votes
2answers
95 views

How to delete a btrfs snapshot?

I'm new to btrfs and I am trying to delete some snapshots I made a few months ago. They're taking up about 20GB of space, and I need that space back. This seems to list the snapshots: ↪ sudo btrfs ...
3
votes
1answer
627 views

How to replace QEMU binary with newer version for libvirt live snapshots

This is my first post, so please be gentle. :) My CentOS 6.5 box has a QEMU binary that does not support live external snapshots. This is the command I attempt on the virsh CLI, and its output: ...
3
votes
2answers
176 views

See progress of lvm --merge

Is there any way I can see the progress of a merge of my snapshot back to the origin? The only thing I know is that there is an ongoing merge because I can't create a new snapshot.
3
votes
3answers
1k views

OpenBSD and filesystem snapshots

What is the best solution, if any, for carrying out LVM style filesystem snapshots on OpenBSD?
3
votes
2answers
194 views

LVM snapshot of btrfs volume changes mounted device

I have a btrf volume on top of LVM. Now I want to do a snapshot on the lvm level (NOT on the btrfs level). But every time I create the LVM snapshot, btrfs changes the mounted block device to the ...
3
votes
1answer
2k views

Is it a bad idea to do an OVF Export of a VM with snapshot data?

I'm currently using a VM running on ESXi 5.0 to dry-run installation procedures for a software product. We're trying a whole different bunch of things, so I'm making extensive use of snapshots to save ...
3
votes
1answer
2k views

What would cause huge amounts of snapshot lag with NetApp Snapvault?

Our NetApp filer shows huge amounts of lag for snapvault operations. What could be possible causes of such large snapshot lag? Snapvault is ON. Source Destination ...