Saturday, March 9, 2013

"rsync over ssh" to a Synology NAS – IPKG, opkg

Nota Bene / before:
  • This is the text, that helps me personally re-installing rsync, whenever it magically disappears, maybe caused by an DSM update.
  • True, I should bring a little structure into this article.
  • I never ever care about rsyncd, as I am doing "rsync over ssh";  any activity suggested regarding rsyncd does not concern me. (But then sometimes I am misled, and I erroneously do invest time in false paths, and I do get into problems that are actually rsyncd-related.)
  • I have my own ways of backing up data.
  • I have my own ideas of keeping data long term outside my computer's built-in disks.

The Synology system provided rsync is not for me. It's somehow modified and spoilt.

backup - Rsync over ssh: "ERROR: module is read only" suddenly appeared - Server Fault

Well, it's not only me experiencing weird effects with the "built-in" rsync. And I think, quite a few of the answers to that forum article do not quite fit at all.

The details of the case:
  • "rsync over ssh" does not use the remote rsync daemon at all, i.e. no rsyncd.conf applies
  • it's not unlikely, that these rsync problems have to do with a Synology special version of rsync
  • after this: "DiskStation> /usr/syno/etc.defaults/rc.d/S84rsyncd.sh stop", the error message does not change, so it's really not an "rsync daemon" issue, as that one is no longer running
I fixed this problem by installing an rsync package provided on an Unslung Project repository for the CPU used within my Synology NAS. This brings dependencies on the Unslung Project, their IPKG installer, their Optware, their specific Synology repository. This kills me a little, to be honest.

I mainly followed the "German Synology wiki" on IPKG. (Anxiously as I am, I do keep a backup of that article at …/com/synology-wiki.de/ . Yes, I do have an idea, that this step alone is rather in vain.)
So, well 1st I had to install IPKG itself.
My CPU on the DS213+ is an e500 (actually: e500v2), so I went the e500 way in their description.
My CPU on the DS112+ is a "Feroceon 88FR131 rev 1 (v5l)", there is a note on how to deal with the DS112+, pls follow that one.

Then I installed the rsync package provided by IPKG.

An entry for /etc/rc.optware got created in /etc/rc.local, and they suggest to remove it, and I did that.
I am not sure, it concerns me at all, as I mention "my" rsync on the NAS by full path on my command lines outside the NAS.

Now my only minor problem with the "alternative rsync" is, that I have to specify the remote rsync on my local rsync command lines like this: "--rsync-path=/opt/bin/rsync". That's a PITA, but that's not too hard.

Update 2013-08-31: en.wikipedia.org/wiki/Ipkg says IPKG was discontinued. en.wikipedia.org/wiki/Opkg is the follower, code.google.com/p/opkg/, but it hasn't really taken off.

1 comment:

Marcus LeFlore said...

Very good article on rsync. Here is one from around 1999 but still the very best rsync tutorial I've ever read. Explains it very well IMO: http://tinyurl.com/l37guv8