Snapshots

Last updated: September 25th 2024

Free VPS Snapshots 

Webdock Snapshots are easy to use, reliable and redundant on- and off-site backups for your Webdock server. Webdock performs backups without causing any interruption of your running system. We provide 8 backup slots in total.
Five of the slots are rotated automatically: daily backups going back 2 days and weekly backups going back up to 3 weeks, rotated every Sunday.
The remaining three backup slots are reserved for your own snapshots of this server.
Resilient: Our backups are streamed directly to a remote storage backend where the data is stored utilizing RAID across many drives. Once a week all weekly snapshots are synched out to remote cold storage for further redundancy.
No need to wait: As soon as you trigger the snapshot the server will be backed up from how it is in that instant. You can continue working on the server and make changes without these becoming part of the snapshot or interfering with the procedure in any way.

Performance

Snapshots of your Webdock server are true snapshots in the sense that they capture an exact disk image at the time of snapshotting. Any running processes or contents in RAM are not captured however, and when you restore or provision a server from a snapshot, it will act as it was just rebooted.

Snapshots are not limited in size and will typically be the delta of changes from the last snapshot made. This means that the very first snapshot, or if older snapshots have been rotated out of local storage, the server will take longer to snapshot. On our SSD servers we operate with an average of 200Mb/second snapshot efficiency. This means that a 60GB Webdock server at full capacity should take about 5 minutes. 

Once snapshot, the snapshot needs to be synched from a secondary local drive to our remote storage backend so it's ready to be picked up for provisioning or restoration. This process usually operates at about 200Mb/second,  but speeds may vary depending on network conditions and other factors. You can get an indication of how long a snapshot will take in the Webdock backend panel for snapshots, as there we list the last recorded snapshot duration as seen by our nightly snapshot job

Snapshots mostly incremental

Typically a snapshot is an incremental snapshot which records the changes on the filesystem since the last snap was performed. Sometimes however snapshots will be of the entire disk which will take longer to perform. This is especially true if you have just performed a restore operation or if the snapshot being taken is the very first one.

Snapshots are nightly

Depending on the server location, we always schedule our daily and weekly snapshots to run at night between the hours of 01.00 and 05.00 in the local timezone. This is so we have as little impact on production websites as possible. As mentioned above, snapshotting means that we are reading from disk at full throttle and streaming the data to a remote storage backend. CPU impact is held to a minimum and will never reach more than 1-5% of total server CPU seconds (CPU is used to encrypt the data before sending it down the wire). 

The server will experience higher than usual I/O read activity which might in theory impact your server performance. However, all our servers are SSD and NVMe based so practically speaking you should not notice anything. Usually a nightly snapshot of all servers on a host takes no more than 1-2 hours.

How we estimate snapshot time

Once we have backed up your system once, you will be able to see an estimated snapshot time on the Snapshots page for a server.  This estimate is based on how long it actually took for us to take the nightly automated snapshot.

This estimate can vary from day to day based on whether you have added or deleted data from your server, disk I/O conditions at the time of snapshotting and as we include the time taken to synch the snapshot to our remote storage backend it will also depend on network conditions at the time. 

If you create a snapshot yourself you can expect to see divergence from this estimate, but it should give you a fair idea of how long a snapshot should take. Sometimes snapshotting will be faster, sometimes it will be slower due to the factors mentioned above.

Related articles