Live data from Hacker News

Unison File Synchronizer

cis.upenn.edu

11–20 of 102 posts

Re: Unison File Synchronizer

#11

I can't praise Unison enough. I've been using it every day for over 10 years and is easily one of the most useful pieces of software I've ever come across. I've donated multiple times over the years.

Same. I've been using it for over ten years as well. It always works correctly, which is just amazing.

Re: Unison File Synchronizer

#12
Is this project still going? I used to use it a lot for duplicating my project directories between my lap PC and my home PC. It was so powerful and so useful at the time. Honestly I thought it had died.

I use Syncthing now. It's really useful.

Re: Unison File Synchronizer

#13

How difficult would it be to build a Dropbox clone on top of this?

Pretty hard. Unison is nice, but...

- Unison is written in OCaml, which is (probably) a perfectly fine language but not commonly used

- Unison synchronizes files to files, but for a Dropbox-like system you really want deduplication for space savings (i.e. server-side storage is a bunch of pointers to content-addressed blocks.)

- in general, it's not clear to me that the client is really the hard part of Dropbox. Note e.g. the part where Dropbox now runs its own data centers for cost reasons.

- there's a million fiddly things to get right, and Unison hasn't had that much usage

Re: Unison File Synchronizer

#14

Not to be confused with Panic's Usenet/NNTP client: * https://en.wikipedia.org/wiki/Unison_(Usenet_client)

Nor with the Coda replicating filesystem, which is not to be confused with Panic’s code editor of the same name.

Re: Unison File Synchronizer

#15
I used to use unison to periodically sync files between a host filesystem and a VM filesystem as it was a lot faster - in terms of filesystem performance when not syncing - than using the shared folder functionality provided by the VM.

Re: Unison File Synchronizer

#17
post #10

I can't praise Unison enough. I've been using it every day for over 10 years and is easily one of the most useful pieces of software I've ever come across. I've donated multiple times over the years.

I'm a maintainer of the Unison package in Fedora and I'd love to know which version(s) of Unison you use day to day. In Fedora (and I think this applies in Debian too) we have to maintain 3 versions because Unison isn't interoperable across minor releases. For this reason we package 2.13, 2.27 and 2.40, and I think there is discussion about packaging the latest release too. Keeping these ancient (esp 2.13) versions g…

> Unison isn't interoperable across minor releases.

Ouch! FWIW, Thanks for all your work.

Re: Unison File Synchronizer

#18
post #10

I can't praise Unison enough. I've been using it every day for over 10 years and is easily one of the most useful pieces of software I've ever come across. I've donated multiple times over the years.

I'm a maintainer of the Unison package in Fedora and I'd love to know which version(s) of Unison you use day to day. In Fedora (and I think this applies in Debian too) we have to maintain 3 versions because Unison isn't interoperable across minor releases. For this reason we package 2.13, 2.27 and 2.40, and I think there is discussion about packaging the latest release too. Keeping these ancient (esp 2.13) versions g…

I use it in Debian, which used to (until recently) package 2 versions in every release. This was convenient for me, a conservative user, who might run old-stable on some computers for months before upgrading to stable. I have used workarounds in the past (mount home directory in a container, and sync from within) so I'm fine with a single version in Debian.

But you package for Fedora, which is "upstream" for RHEL (if I'm not mistaken) with their 10 year life cycles, so I'm sure RHEL customers would love you to keep as many versions available as possible :)

Re: Unison File Synchronizer

#19
post #10

I can't praise Unison enough. I've been using it every day for over 10 years and is easily one of the most useful pieces of software I've ever come across. I've donated multiple times over the years.

I'm a maintainer of the Unison package in Fedora and I'd love to know which version(s) of Unison you use day to day. In Fedora (and I think this applies in Debian too) we have to maintain 3 versions because Unison isn't interoperable across minor releases. For this reason we package 2.13, 2.27 and 2.40, and I think there is discussion about packaging the latest release too. Keeping these ancient (esp 2.13) versions g…

This incompatibility is one of the reasons why I reduced my dependency on it, though I still use it for minor things.

The last straw came when it turns out that unison was incompatible with the same version, if that version had been built on a different system. I can't remember the details but there was some library version difference that results in a unison that has the same version number but wouldn't talk to one from another system without crashing.

Drove me crazy.

Post reply on HN