Backup to external drive

[zierbeek]

Hi all, to finalise my 3-2-1 backup, I want to create a backup to an external harddrive. The server is running Truenas as OS.

I would want to do this only for my images and my vm (the hard drive is only 1tb).

What should I use? Duplicate doesn't have the possibility to clone to an external drive.
I checked the resources but It all seemed pretty old and not that relevant anymore.

 

[sretalla]

I checked the resources but It all seemed pretty old and not that relevant anymore.

I think this one still seems relevant:

How to: Backup to local disks

How to: Backups to local disks Overview: This subject comes up often enough that I thought I would start a post of how I do it. Specifically I back up my TrueNAS to a hot-inserted, locally attached disk, then when done, hot-remove and take...

www.truenas.com

 

[zierbeek]

I think this one still seems relevant:

How to: Backup to local disks

How to: Backups to local disks Overview: This subject comes up often enough that I thought I would start a post of how I do it. Specifically I back up my TrueNAS to a hot-inserted, locally attached disk, then when done, hot-remove and take...

www.truenas.com

Thanks but would make use of replication, would that be fine too?

 

[Patrick M. Hausen]

ZFS replication via snapshots is incremental, checksums everything, and is simply the best method.

 

[zierbeek]

ZFS replication via snapshots is incremental, checksums everything, and is simply the best method.

And this can be considered a full backup when one of my drives crashes? These drives are Raid 1

 

[Patrick M. Hausen]

Yes, sure. A replication of a dataset contains exactly the same data as the original dataset at the point of time when the last replicated snapshot was taken.

 

[zierbeek]

Yes, sure. A replication of a dataset contains exactly the same data as the original dataset at the point of time when the last replicated snapshot was taken.

And as such it has the same size?

A best practice to leave it attached or just regularly make a backup of it. not much changes since it are photos and my vm

 

[sretalla]

You could set it with no schedule and to not run automatically, which leaves you clicking the Run Now button when you have attached the disk.

I would suggest not using automatic/scheduled if the drive might be disconnected some of the time.

 

[Patrick M. Hausen]

Same size in total. Successive snapshots only need the differences.

I.e. snapshot main dataset every hour and keep for one week. That means you can restore any file with a granularity of one hour up to one week into the past.
Then replicate i.e. the midnight snapshot once per day to external disk, keep for four weeks. So additionally you can get at past data for four weeks, but only with a granularity of one state every day.

The size requirements depend on the frequency of changes. If nothing ever changes, the replica takes up as much space as the original and all the snapshots are 0 bytes or just a couple of k in size.

 

[zierbeek]

You could set it with no schedule and to not run automatically, which leaves you clicking the Run Now button when you have attached the disk.

I would suggest not using automatic/scheduled if the drive might be disconnected some of the time.

But that would keep the disk spinning all the time?