ReFS and hard links


#1

I know ReFS does not feature hard links but its working well with symbolic links.

Unfortunately UrBackup still tries to create hard links; and is creating WARNING log entries.
Although I enabled the advanced option Use symlinks during incremental file backups.

I do have the strong feeling that this "in-vane try"slows down backup.
Is there any configuration option to prevent UrBackup to try creating hard links at all or to use symlinks preferred do hardlinks?


Backups failing (Cannot create Directory)
#2

No, it is designed to work with hard links or reflinks. And ReFS has neither.


#3

Does this mean my backups to the ReFS volume are not reliable?
Creation of symlinks seems to work very well.
If a hardlink can not be created the file is copied (same as if your hardlink capacity would be exausted).

PS: I know the difference between hard- / symbolic-links and junctions. ReFS is supporting symbolic-links and junctions.

To me the Backup seems to be OK.

The idea it just not trying creating hardlinks at all because the file system is not supporting it and using symbolic links not only for directories with more than 10 entries.


#4

Just read that ReFS v2 in Windows Server 2016 has reflink support. Will add support for this together with XFS reflink support.

I don’t think there is a way to upgrade a ReFS v1 to v2 in place. Not a really good choice for a production file system it seems :wink:


#5

I use Stablebit Drivepool for backup storage. It does not support hard links, but it does support symlinks. Is there a way to force symlinks over hardlinks?

Currently, it tries to create hardlinks, errors out and creates a new file. Every incremental backup is taking up significant space. Even just deleting a few files from the source triggers new files to be generated at the destination.

Thanks!


#6

Version 2.3.x works with ReFS v3 now (it uses reflinking).


#7

Hi uroni - My issue is not with ReFS support for hard links, but StableBit DrivePool’s lack of support for hard links. Same issue as the OP, but caused by different reasons. So ReFS supporting hard links does not address my issue.

The devs as StableBit have admitted they have stopped trying to add hard link support - their implementation of NTFS is basically incompatible with it at a fundamental level so that is a dead end - it will never be supported. So, I am curious if on Urbackup there was a way to side-step this lack of compatibility by simply replacing hardlinks with softlinks. I know they do not function the same way and are not inherently interchangeable, but it would likely dramatically improve things for myself, and anyone else backing up to destinations where hardlink support is flaky or non-existent.

Thanks for any recommendations.


#10

That wasn’t an answer to your question.

Obviously the correct thing for you to do would have been to open a new thread, e.g. “File backup without hardlinks, only symlinks” and to post that to “feature request” category. Not to go around and post to/necro several two year old threads with only tangentially related topics.


#11

My apologies. Considering you had responded to the same 2 year old post directly after me, I had assumed continuing the conversation here would be appropriate.

Also, again, my basic question is still the exact same as the OP and considering Urbackup serves a pretty broad range of users and needs, it seemed most appropriate to post here and hopefully regain the attention of this very specific subset of users who would actually care about, or have knowledge on this topic.

I will follow your retroactive recommendation and open a new thread. Thank you.