[CentOS] Fail Transfer of Large Files
jay.leafey at mindless.com
Sun Nov 21 00:17:23 UTC 2010
Les Mikesell wrote:
> On 11/19/10 3:16 PM, Michael D. Berger wrote:
>> On my intranet, I sometimes transfer large files, about 4G,
>> to an CentOS old box that I use for a web server. I transfer
>> with ftp or sftp. Usually, before the file is complete, the
>> transfer "stalls". At that point, ping from the destination box
>> to the router fails. I then deactivate the net interface on the
>> destination box and then activate it. Ping is then successful,
>> and the transfer is completed. The transferred file is correct,
>> as verified with sha1sum.
>> All connections are via cat6 wire.
>> So what do you think? Should I try changing the net card?
>> Any tests to run? Any other suggestions?
> I haven't seen anything like that, at least in many years so it probably is
> hardware related - but make sure your software is up to date. As a workaround,
> you might try using rsync with the --bwlimit option to limit the speed of the
> transfer - and the -P option so you can restart a failed transfer from the point
> it stalled on the last attempt.
This does ring a bell, but the circumstances were a bit different. In
our case we were transferring large files between "home" and a remote
site. SFTP/SCP transfers were stalling part-way through in an
unpredictable manner. It turned out to be a bug in the selective
acknowledgment functionality in the TCP stack. Short story, adding the
following line to /etc/sysctl.conf fixed the issue:
> net.ipv4.tcp_sack = 0
Of course, you can set it on-the-fly using the sysctl command:
> sysctl -w net.ipv4.tcp_sack=0
It helped in our case, no way of telling if it will help you. As usual,
your mileage may vary.
Jay Leafey - jay.leafey at mindless.com
-------------- next part --------------
A non-text attachment was scrubbed...
Size: 5529 bytes
Desc: S/MIME Cryptographic Signature
More information about the CentOS