Basic to Basic folder sync

[Nfly79]

 

Hello.

I'm looking for a solution the second day and so far failed (I apologize for not very good knowledge of the language).
So, there are two HDDs. The system created as two Basic volumes.
So, I have valuable data and not valuable.
For valuables I want to do a mirroring between two disks (similar to the software Raid1).
Not valuable data fill both volumes evenly. It makes no sense to do Raid 1 for non-valuable data, I can always restore them. And losing two volumes for them is irrational as for me.
But I do not see options for mirroring. Hyper Backup backs up to a large file. Rsync allows you to copy only to another source.
Snaphot Replication does something similar (you can make a copy to another partition), but I doubt that the snapshot works without the original files. And if I understand correctly, this is not a backup tool.In general, I am close to spitting and rolling a common Raid 1.

Edited March 25, 2019 by Nfly79

[flyride]

I use SnapShot replication between two systems as backup.  If you understand what it is doing, it is extremely effective.  Enterprise storage systems use snapshotting for backup all the time.

 

I'm not sure what you mean by "snapshot works without the original files."  A share is snapshot to another (new) target share.  These can be set up in each direction on your two volumes just fine, as long as you have the space on each.

 

[Nfly79]

10 часов назад, flyride сказал:

I'm not sure what you mean by "snapshot works without the original files."  A share is snapshot to another (new) target share.  These can be set up in each direction on your two volumes just fine, as long as you have the space on each.

thanks for your reply
Correct me if I'm wrong, the snapshot does not take up disk space as it stores a record of compliance with the original. If the original files change, the snapshot is enlarged to save the changes.
I repent, I understand how it works within a single volume. But how does a snapshot work with another volume? Do I understand correctly that this will be a simple copy?

[flyride]

Ah, I understand your question now. Yes a snapshot is a point in time reference so that subsequent changes only are stored as the new blocks. But each snapshot references all files in the file system. So when a snapshot is replicated, it initially is a copy of all files in the file system at that point in time. Subsequent replicated snapshots will realize the common blocks on the target so only the updated blocks will be copied, and then you have the same point in time views on both file systems.

[Nfly79]

31 минуту назад, flyride сказал:

Ah, I understand your question now. Yes a snapshot is a point in time reference so that subsequent changes only are stored as the new blocks. But each snapshot references all files in the file system. So when a snapshot is replicated, it initially is a copy of all files in the file system at that point in time. Subsequent replicated snapshots will realize the common blocks on the target so only the updated blocks will be copied, and then you have the same point in time views on both file systems.

 

In this case, I correctly understand that at the death of the first HDD, the data on the second НDD will be saved?
In other words, can we say that the snapshot provides something like Rade1 emulation?

Edited March 26, 2019 by Nfly79

[flyride]

It is not at all like RAID1.

 

In your original premise, you identified two independent hard disks with two filesystems.  You then suggested that you want to use a replication strategy (which is temporal - i.e. HyperBackup, rsync, btrfs Snapshot).

 

With RAID1, a real-time copy of your data would exist on both drives simultaneously, and at all times.

 

With a temporal replication, the data you select for replication is duplicated on intervals you specify.  At other times new data is not replicated.  However, a temporal replication strategy may be more efficient with disk utilization (as you point out) and will be tolerant of source file system corruption or file deletion (Snapshots with multiple copies).

 

[Nfly79]

15 часов назад, flyride сказал:

It is not at all like RAID1.

That is what I meant. You are right, it is incorrect to call it Reid. I mean the goal, but I call the tool. Thank you for the clarification.