Repair failed, not enough repair blocks (...)

[Satchmo77]

Hi all,

I use SABnzbd 1.1.1RC2 on my Ubuntu 16.04.1 Server.

Recently my downloads are "finishing" with the error "Repair failed, not enough repair blocks (...)"

I then copy the downloaded folder from the incomplete folder to my Windows computer. I then
start quickpar 0.9.1 and the program tells me for example "Ready to recover using 4/150 recovery blocks"

quickbar then repairs the files and I can unrar them. I don't know if this is a sabnzbd problem or something
else. At the moment I don't understand why sab is missing blocks to repair and quickbar repairs it without
problems.

Regards

[sander]

In such cases I would do a manual unrar on Ubuntu itself. Possibly with the option "-N".

I believe there is a SABnzbd config parameter (something with "check" or so) which you can turn off, which can also improve results. @safihre knows that switch ....

I've experienced the same on my Ubuntu

[Satchmo77]

The steps are
1) Download
2) Check
3) If necessary get par files and repair the downloaded files
4) unrar files

correct, or?

if yes, then step 3 is not working / functioning and I can only perform step 4 when the files are repaired. I don't know how to do that on
ubuntu therefore I copy the broken files to my windows computer and check and repair the files. (step 3). Question is why step 3 works
on Windows but not on Linux. I just enabled the switch "Download all par2 files". Maybe this helps somehow.

[jcfp]

if yes, then step 3 is not working / functioning and I can only perform step 4 when the files are repaired. I don't know how to do that on
ubuntu therefore I copy the broken files to my windows computer and check and repair the files. (step 3). Question is why step 3 works
on Windows but not on Linux. I just enabled the switch "Download all par2 files". Maybe this helps somehow.

This has to do with a protection against a potential denial of service built into recent versions of par2. That precaution sometimes causes it to skip data and not find 'data blocks' if they are offset too far within the files being verified. Older versions of par2 as well as other implementations typically do check all data and thus may at times find more blocks within certain broken files.

Xenial has par2 at version 0.6.14, which may skip data unless instructed otherwise by command line argument -N. The old behaviour can be restored in sab by putting that argument in Extra PAR2 Parameters under config->switches. Note that in future versions of par2 this behaviour is set to change yet again, going back to checking all data by default with the meaning of -N being inverted (see https://github.com/Parchive/par2cmdline ... 87733ff0b5).

[Satchmo77]

jcfp thank you! the Extra PAR2 Parameters -N under config->switches did the trick.