[CentOS] Networking issue, C6.2 LiveDVD x86_64

Mon Apr 23 17:48:59 UTC 2012
Lamar Owen <lowen at pari.edu>

Good afternoon, CentOS list.

I am beginning triage of a rather wierd issue I experienced Saturday with CentOS 6.2 LiveDVD, x86_64.  I'm posting this information in hope that someone may have seen something similar.

I use a USB key with CentOS 6.2 LiveDVD loaded, with an encrypted home filesystem, built using the instructions on the CentOS wiki for a LiveUSB build, and it was built by a CentOS 6.2 x86_64 system with the livecd-iso-to-disk.sh tool.  It has worked fine for general usage for a while, now.  

I began a disk image backup of a Dell Inspiron 1420 laptop Saturday, using dd piped into ssh to a file, on an RHEL6 server (RHEL6.2, i686 dist, fully updated).

The command line used on the laptop, booted into the C6 LiveDVD environment, was:
dd if=/dev/sda |ssh root at rhel6-server-used.local cat \>/opt/backups/sda.img
which I have used before, on this specific laptop, without incident, booted into Fedora 14 Security LiveCD 32-bit.

Something, however, in this particular combination is creating an issue.  After approximately 3MB or so of the image is transferred, no network traffic at all can flow, causing the transfer to hang.  And I mean hang, with unresponsive terminals in GNOME, and a non-killable ssh process.  It seems to disrupt the server as well, but, like I said, I'm just beginning triage of the problem, so am still gathering data.

Now, I booted my trusty Fedora 14 i686 Security Live CD (which boots into LXDE), and the transfer to the same server, using the same cable, same switch, and same hardware all the way around is going smoothly (25GB into a 500GB transfer so far). So I tend to think that it is not a hardware problem. 

I'm going to next try a CentOS 6.2 LiveUSB using the 32-bit LiveDVD instead of the 64-bit one, hopefully set up as identically as possible to the 64-bit one I've been using, and then see if it's a 32-bit versus 64-bit NIC driver issue or similar.  Incidentally, the ethernet device gets a 'p3p1' device name instead of 'eth0.'

I'm somewhat concerned by this, since I'm upgrading the laptop in question to CentOS 6.2 as part of this process, so I want to track down the problem so that if I need to install the 32-bit version instead of the 64-bit version I can. 

So, if anyone has had specific experience with a Dell Inspiron 1420n (came with Ubuntu pre-installed, incidentally) and CentOS 6 64-bit, I'd be interested in hearing it.