ass-u-me: faulty troubleshooting on the NAS

I mentioned earlier that my WD worldbook NAS was apparently dying.  It might be (can’t tell yet), but that wasn’t the real problem.

The symptom was deadly-slow xfer speeds to/from the NAS drive and the USB hd daisy-chained to it.

Testing revealed that:

  • sometimes it worked fine
  • sometimes it worked better from other workstation other than my own
  • but when it fell over it seemed to cause collateral damage;  I attributed this to the cifs/smb network mounted drives becoming practically unavailable.
The real problem revealed itself when I noticed both the his/her Dell antiX laptops were having problems staying on the LAN.  I wan’t used to antiX’s default wicd network tool and assumed it, or my use of it, were faulty.
Googling, googling.  Found a reference to similar symptoms and a fix using ethtool to drop the workstation’s card to 10Mbits/sec rather than some higher number if your router was not playing well.  Tried this and BAM! the connections were rock solid, albeit slow.
Hmm.
My devices were not plugged into a router, but into a switch.  I wonder….
Oh crap.  I went to my non-fixed workstation and looked at dmesg;  eth0 100 was up/down, up/down.  Applied the fix;  instant relief.
So I plopped my backup switch on top and jacked in the cables. All working.
Reset the boxen to their natural speeds; all working.
Did my rsync-based backup routine and speeds are back to reasonable levels for my dinky network:
music/00sorted/pop/Madonna/Immaculate_Collection-ogg/07 - Into_The_Groove.ogg
     3439316 100%    3.19MB/s    0:00:01 (xfer#4582, to-check=25707/42687)
music/00sorted/pop/Madonna/Immaculate_Collection-ogg/08 - Live_To_Tell.ogg
     4363017 100%    3.67MB/s    0:00:01 (xfer#4583, to-check=25706/42687)
So the problem is with the switch.  Dying?  Dunno.  Needs a time out after a few years of constant duty?  Maybe.  I noticed while xferring cables that I had about 5 cables plugged into it that didn’t terminate anywhere.  Dunno if that could cause it confusion.  BTW, my google-fu is failing on researching that possibility,
I learned a great deal fighting this issue, but would have learned faster had I been looking for simpler solutions.  “When you hear hoofbeats, look for horses not for zebras.”  Folksy version of Occam.
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