This has happened to me in the past. It is not an OS problem, it was for me a hardware issue. One or both of two things may be causing this problem. Some USB keyboards require more power than others. My USB keyboard would exhibit these same symptoms when plugged into a hub that was powered only by the computer itself or another hub. So my particular USB keyboard must be plugged into a hub that has its own power supply. Also, I have found that some USB keyboards are especially likely to exhibit these same symptoms when plugged into an unpowered USB 3 port. Login remotely via SSH never exhibited any of these keyboard symptoms. Perhaps this is the cause of your problem as well. On 08/28/2014 04:30 AM, Reinhard Dunkel wrote: > On 08/27/2014 06:07 PM, SilverTip257 wrote: >> On Tue, Aug 26, 2014 at 10:54 PM, Reinhard Dunkel <dunkel at sciencesoft.net> >> wrote: >> >>> I used CentOS 5 for years. Suddenly, it takes one second holding a >>> keyboard key until it shows on the screen: >>> >>> >> Is this system accessible via SSH? >> Does the behavior only happen when using the physical keyboard? >> >> Might it be out of physical memory (RAM) and swapping violently? >> Disk thrashing of this sort can cause rather irritating delays. >> >> Or maybe a failing or failed drive? (Assuming you could have a hardware or >> software RAID setup) > Does CentOS now only support user request tracking by email? I cannot > find this thread on the CentOS web site... > > My computer has 4 GB Patriot memory - the maximum amount the motherboard > allows. Using command "top" shows less than one percent of CPU and > memory are in use. The computer is idle. I am using a 1 TB WD disk for > CentOS 5 and a 2 TB Seagate disk for CentOS 7. No RAID. > > On CentOS 5, I use command "su" to show a root shell. On CentOS 7, su no > longer works and I use "ssh root at localhost" instead. (I have not tried > SSH to access my CentOS systems remotely yet.) > > Concerning a previous comment: I did not modify the hardware likely > causing this problem. I only have to switch between both disks - > described above - to boot CentOS 5 or CentOS 7. My suspicion is "yum > update" using numerous official and unofficial "repos" installed > something causing this challenge. The login screen of CentOS 5 for user > name and password still works fine. By the way, we develop software > (NMRanalyst) and I try to keep a CentOS 5 system alive so we can test on > it to claim our software is supported on it. When I don't get further > suggestions, I likely re-install another disk with CentOS 5 - this time > using only official repos. > > ThanX for all suggestions! > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > > -- > > > ********************************************************* > David P. Both, RHCE > Millennium Technology Consulting LLC > 919-389-8678 > > dboth at millennium-technology.com > > www.millennium-technology.com > www.databook.bz - Home of the DataBook for Linux > DataBook is a Registered Trademark of David Both > ********************************************************* > This communication may be unlawfully collected and stored by the National Security Agency (NSA) in secret. The parties to this email do not consent to the retrieving or storing of this communication and any related metadata, as well as printing, copying, re-transmitting, disseminating, or otherwise using it. If you believe you have received this communication in error, please delete it immediately. >