bad response from system

lemon09 · 09-25-2009, 01:38 PM

hello friends,

my bash shell is reacting unusually all these days.
i dont know why
when ever i press tab for auto completion the application(the shell) hangs.
i have to close it to start it again.

even my machine has become very slow these days

can anybody fix the problem

mazinoz · 09-25-2009, 08:15 PM

I suspect you have been hacked. Although as a temporary measure unplugging and replugging USB devices may help. Seriously, use another computer to download security programs and reinstall.

lemon09 · 09-28-2009, 05:24 AM

Quote:

Originally Posted by mazinoz

I suspect you have been hacked. Although as a temporary measure unplugging and replugging USB devices may help. Seriously, use another computer to download security programs and reinstall.

can you be more clear.......

zhjim · 09-28-2009, 06:11 AM

I sometime have a similar behave that auto completion hangs when I'm doing high I/O intensive task. Namely downloading files to harddisk.
Reason for this is that the autocompletion looks up the possible names from disk....

Maybe see if it just takes some time to have the autocompletion or if it realy hangs forever.
Unplug the USB devices might do something. Also you could try if it just happens on certain directories or for every dir.

lemon09 · 09-29-2009, 01:40 AM

Quote:

Originally Posted by zhjim

I sometime have a similar behave that auto completion hangs when I'm doing high I/O intensive task. Namely downloading files to harddisk.

auto completion hangs even when no such task is performed

Quote:

Maybe see if it just takes some time to have the autocompletion or if it realy hangs forever.

i shall give this a try.

Quote:

Also you could try if it just happens on certain directories or for every dir.

well for commands(like halt, top, ps - to say, for all commands), hardly there's any problem.......it happens that when any directory is involved it hangs....

lemon09 · 09-29-2009, 01:44 AM

i have also noticed that my computer has become very slow.

it takes a lot of time to start....

commands like yum takes a lot of time to produce the desired output...

i don't understand the thing. it was not like this before.

lutusp · 09-29-2009, 03:30 AM

Quote:

Originally Posted by lemon09

i have also noticed that my computer has become very slow.

it takes a lot of time to start....

commands like yum takes a lot of time to produce the desired output...

i don't understand the thing. it was not like this before.

Your system might be compromised, or it might be out of HDD space or RAM, or it might be running mostly in swap, or it is desperately trying to do something it cannot complete.

Try running "top" and see what is going on:

Code:

$ top

This might show a process hogging system resources.

Or check the state of your drives:

Code:

$ df

Or of memory:

Code:

$ free

lemon09 · 09-30-2009, 03:06 AM

first of all thanks to all of you for your pains:

Quote:

Your system might be compromised, or it might be out of HDD space or RAM, or it might be running mostly in swap, or it is desperately trying to do something it cannot complete.

well it might be helpful to provide you with the proper configuration of my pc.
i have:

Code:

1. CPU -> AMD Phenom X3 (tri core)
2. RAM -> 4 GB
3. HDD -> 500 GB

i don't think i deal with such complicated things that would require a system with higher configuration.

yet i gave a try:

the total CPU usage didn't exceed 50%.

swap space usage is 0

Code:

$ free
             total       used       free     shared    buffers     cached
Mem:       2984020     962772    2021248          0      25720     450444
-/+ buffers/cache:     486608    2497412
Swap:      5046264          0    5046264


$ df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
                     100791728   6506336  89165392   7% /
/dev/mapper/VolGroup00-LogVol02
                     122724388   4376248 112114028   4% /home
/dev/sda8               194442     20826    163577  12% /boot
tmpfs                  1492008       336   1491672   1% /dev/shm

lemon09 · 09-30-2009, 04:38 AM

recently i noticed that even when i press "ha" for auto-completion it hangs.....

i really cant make this out..........

please help me out.

zhjim · 09-30-2009, 07:43 AM

please check on the throughput of the disk

Code:

hdparm -tT /dev/sda

substitute /dev/sda with your harddrive.
Notherthing to check on is with vmstat

Code:

vmstat 1

Have this run in a terminal by its own and then try autocompletion. vmstat will show you the disk and other usage stats.

lemon09 · 09-30-2009, 02:07 PM

@ zhjim

i am so much thankful to you
it has been a lot of help to me.

but can you be more clear.......i mean what did the command do at last..

chrism01 · 09-30-2009, 07:24 PM

http://linux.die.net/man/8/hdparm

Quote:

-T
Perform timings of cache reads for benchmark and comparison purposes. For meaningful results, this operation should be repeated 2-3 times on an otherwise inactive system (no other active processes) with at least a couple of megabytes of free memory. This displays the speed of reading directly from the Linux buffer cache without disk access. This measurement is essentially an indication of the throughput of the processor, cache, and memory of the system under test. If the -t flag is also specified, then a correction factor based on the outcome of -T will be incorporated into the result reported for the -t operation.
-t
Perform timings of device reads for benchmark and comparison purposes. For meaningful results, this operation should be repeated 2-3 times on an otherwise inactive system (no other active processes) with at least a couple of megabytes of free memory. This displays the speed of reading through the buffer cache to the disk without any prior caching of data. This measurement is an indication of how fast the drive can sustain sequential data reads under Linux, without any filesystem overhead. To ensure accurate measurements, the buffer cache is flushed during the processing of -t using the BLKFLSBUF ioctl. If the -T flag is also specified, then a correction factor based on the outcome of -T will be incorporated into the result reported for the -t operation.