30%+ Failure Rate (CRC/PAR) but Retry works

[anarche]

Hello all,

I'm getting a 30-40% failure rate on any type of NZB's downloaded usually with a CRC/PAR error. However if I click retry, then retry again (without supplying additional NZB) they almost always process fine. I've tested the same NZB's on my brothers sab setup and they process fine. I've searched the forums for a few days now without finding a result so I'm finally posting.

Here is a link to a pastebin of the full log file of my most recent failed download. If anyone can offer any insight it would be greatly appreciated. http://pastebin.com/fdkGzjMH

Thanks,
AnarchE

[shypike]

Sound like less than reliable hardware or some memory issue.
Have you tried the option "Pause Downloading During Post-Processing" in Config->Switches?
This will reduce the stress on your system.

[anarche]

I have tried Pausing during post-processing. Can you suggest any ways to test the reliability of the hardware to prove that's the problem? (Linux, Ubuntu) The computer is basically a dedicated File Server that I put sab on to keep the downloading/processing done "locally".

Hostname: chaos - OS: Linux 2.6.32-34-generic-pae/i686 - CPU: AMD Sempron 3000+ (1000.000 MHz) - Processes: 144 - Uptime: 10d 21h 34m - Users: 1 - Load Average: 0.01 - Memory Usage: 480.55MB/1000.98MB (48.01%) - Disk Usage: 1634.24GB/2875.01GB (56.84%) (All 2.8TB is RAID1)

[anarche]

I'm running MemTest86+ right now off Hirens Boot CD. So far so good. Any other suggestions?

[shypike]

I guess it's an older and somewhat slow system.
If the pause-download solves the problem, I would leave it like that.
Given the speed of your system, parallel download and post-processing
might be slower than working sequential.

[anarche]

Pause download didn't solve the problem.

I can "retry" while downloading and everything works fine. I can also par/unrar from command line while downloading without problems too.

It almost seems like it's trying to repair/extract before the download is complete. Any other suggestions?

[sander]

I guess it's an older and somewhat slow system.
If the pause-download solves the problem, I would leave it like that.
Given the speed of your system, parallel download and post-processing
might be slower than working sequential.

Shy, the AMD Sempron 3000+ is a 1600 / 1800 / 2000 MHz processor. I'm typing this on an Atom N270 @ 1.60GHz (so: slower), and SABnzbd works great on this machine. So I think the problems are not caused by the CPU speed.

[anarche]

This Sempron is 1800MHZ, just showing 1000MHZ in that because it was in power save mode.

Thanks for the note sander.

[sander]

A few remarks:

There are a lot of missing articles in your pastebin paste. If you retry (and it works), does the log show the same missing articles? If not, the articles are suddenly there, apparently. So: do you download too new posts which are still being uploaded?

Does your brother have an extra newsserver defined?

And: I would lower the number of newsserver connections to 2.

[anarche]

I will say sometimes it is a result of the NZB being too new, however that's probably only 25%. Usually it doesn't actually download anything, it just retries the repair/unrar and that works. If it would help I can give you more examples from the logs.

No he doesn't.

Ok I'll give that a try. Can you elaborate on why that helps?

[sander]

I'm thinking the problem is not in SAB, but on the newsserver side; if a message is missing, but in a retry it is there, that's a newsserver problem (or it's too new). The method to determine this: check your log file for the article number. (If you have 'grep', it's easy).

Lower newsserver connection: just a try too avoid stress on the newsserver side.

[anarche]

I'll be downloading quite a few nzb's* tonight, so I'll report back with my results.

Typically the news server has been flawless (brother uses the same one). Usenetserver.com.

I tried lowering my connection count down to 2 and I was getting about 300k/sec. Upped it to 5 and am back to getting around 3.1mb/sec.

I will check my logs tonight if any fail and report back. Thank you very much for your input sander, I really appreciate it. And thank you shypike for some awesome software.

~AnarchE

[anarche]

Okay, ran into the same problem tonight. I lowered the connections to 5, ensured pause during post processing was on, and it still failed. Immediately clicked Retry/Retry and it worked fine.

When you have a minute please take a look at the log below and let me know if you see anything.

http://pastebin.com/M7AAYGRR

[sander]

After you clicked Retry, was there any additional download? I don't see any download at all in your log: no "missing" message like in your earlier log.

If there is no additional download, it's probably a hardware error. Can you run memtest?

[anarche]

There was no additional download.

Ran memtest for nearly 4 hours earlier and only got 1 error.