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Recently my wireless network has being stopping to transfer data from some irregular time intervals that vary from 30 seconds to 20 minutes, and every time I need to plug off and then on the wireless adapter.

Using ping (ping 8.8.8.8) to see what happens, and when data transfer stops I receive this message:

ping: sendmsg: No buffer space available

So I found out that a solution for this is to increase buffer size with this command:

sudo echo 83886080 > /proc/sys/net/core/wmem_max

Although I can't execute this command, when I hit enter I get this:

bash: /proc/sys/net/core/wmem_max: Permission denied

Trying the command without sudo or with gksu returns the same message. Through GEdit I can open /proc/sys/net/core/wmem_max file, and opening as administrator it enables me to click the 'Save' button, although after changing the value and hitting the button it returns me this message:

Could not create a temporary backup file while saving /proc/sys/net/core/wmem_max

gedit could not backup the old copy of the file before saving the new one. You can ignore this warning and save the file anyway, but if an error occurs while saving, you could lose the old copy of the file. Save anyway?

And even clicking in the 'Save anyway' button it returns the very same message.

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marked as duplicate by Gilles, Anthon, Mat, slm, jasonwryan Jun 8 '13 at 20:40

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1 Answer 1

up vote 1 down vote accepted

Your sudo command does not write the data as root. Only executes echo as root. Try

sudo -s -H
echo 83886080 > /proc/sys/net/core/wmem_max
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That worked like a charm! Thanks, I tried to became root by typing su although it asks for my password and show me: su: Authentication Failure and I am sure the password is correct, why does su doesn't seem to work and sudo -s -H does? –  Rodrigo Martins Jun 8 '13 at 3:49
1  
That is essentially another question. The answer is that on most systems sudo is set up to ask for your password, where su always asks for the password of root. They use different mechanisms. su does not remember you authenticated after you exit, sudo does (for 5 minutes in most set ups). –  Anthon Jun 8 '13 at 3:54

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