RHEL 5.6 "ls -l" command hang

noob189 · 12-13-2012, 09:44 PM

Hi guys,

I having issue on execute command "ls -l" hanging for few minutes, Normally this only happen on folder has many files/folder. but now it happen on small files/folder too.
i hope i can find the solution in this forum before i escalate to red hat support.

Please advise.

Thanks.

malekmustaq · 12-13-2012, 09:54 PM

It could probably be that your 'ls' is tied to a circuitous alias; before you detach it you first make a back up (we don't know what the RH people wanted it to), so back it up:

Code:

alias >> my_aliases.txt

then (I am only assuming it is aliased, as usually it is with most distros), remove the alias to run 'ls' in plain vanilla--

Code:

unalias ls

Exit. Launch. (Terminal.) Check use ls.

Hope that helps.

Note: If this doesn't work check your system for "rootkits"! clean and install a fresh copy of bash.

Good luck.

Valery Reznic · 12-14-2012, 09:47 AM

Quote:

Originally Posted by noob189

Hi guys,

I having issue on execute command "ls -l" hanging for few minutes, Normally this only happen on folder has many files/folder. but now it happen on small files/folder too.
i hope i can find the solution in this forum before i escalate to red hat support.

Please advise.

Thanks.

Is just 'ls' command take a long time too?

If 'ls' is quick and 'ls -l' is slow - do you by any chance use NIS/NIS++?
Is your NIS server OK?

linosaurusroot · 12-14-2012, 10:24 AM

Is "ls -f" much faster? That doesn't bother to sort names into order (so saves time).

Putting too many files into one directory is unwise partly for the performance hit. Is it a local filesystem, and what format?

noob189 · 12-17-2012, 03:16 AM

Hi all,

Sorry for late reply.

Quote:

Is just 'ls' command take a long time too?

If 'ls' is quick and 'ls -l' is slow - do you by any chance use NIS/NIS++?
Is your NIS server OK?

'ls' command quick print the output. it's has problem with 'ls -l,ls -la & ll' command it's take a couple of minute to print the output.

Quote:

Is "ls -f" much faster? That doesn't bother to sort names into order (so saves time).

Putting too many files into one directory is unwise partly for the performance hit. Is it a local filesystem, and what format?

i try 'ls -f' it fast same as i executing command ls
yes it is a local filesystem format ext3.

@malekmustaq - i tried 'unalias ls' the output
[root@mymcb-nbm02 ~]# unalias ls
-bash: unalias: ls: not found

i'm beginner in linux technical issue.
Please advise

Thanks.

linosaurusroot · 12-17-2012, 04:04 AM

Quote:

'ls' command quick print the output. it's has problem with 'ls -l,ls -la & ll' command it's take a couple of minute to print the output.

In that case your problem comes from looking up UIDs to usernames (could involve NIS as suggested by another user).
Do you have full disk in /tmp/ or /var/tmp/ ? This could interfere with caching.
What's in your /etc/nsswitch.conf ?

noob189 · 12-17-2012, 10:04 PM

Quote:

Originally Posted by linosaurusroot

In that case your problem comes from looking up UIDs to usernames (could involve NIS as suggested by another user).
Do you have full disk in /tmp/ or /var/tmp/ ? This could interfere with caching.
What's in your /etc/nsswitch.conf ?

full disk you mean the capacity for /tmp/ or /var/tmp ?

Code:

Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/cciss/c0d0p3    130521568  34179212  89605100  28% /
/dev/cciss/c0d0p1       194442     12172    172231   7% /boot
tmpfs                  3051140         0   3051140   0% /dev/shm
tmpfs                  3051140      1248   3049892   1% /tmp
/dev/cciss/c0d1p1    576674672    218820 547162476   1% /netbackup_restore

this is in my /etc/nsswitch.conf

Code:

#
# /etc/nsswitch.conf
#
# An example Name Service Switch config file. This file should be
# sorted with the most-used services at the beginning.
#
# The entry '[NOTFOUND=return]' means that the search for an
# entry should stop if the search in the previous entry turned
# up nothing. Note that if the search failed due to some other reason
# (like no NIS server responding) then the search continues with the
# next entry.
#
# Legal entries are:
#
#       nisplus or nis+         Use NIS+ (NIS version 3)
#       nis or yp               Use NIS (NIS version 2), also called YP
#       dns                     Use DNS (Domain Name Service)
#       files                   Use the local files
#       db                      Use the local database (.db) files
#       compat                  Use NIS on compat mode
#       hesiod                  Use Hesiod for user lookups
#       [NOTFOUND=return]       Stop searching if not found so far
#

# To use db, put the "db" in front of "files" for entries you want to be
# looked up first in the databases
#
# Example:
#passwd:    db files nisplus nis
#shadow:    db files nisplus nis
#group:     db files nisplus nis

passwd:     files nisplus
shadow:     files nisplus
group:      files nisplus

#hosts:     db files nisplus nis dns
hosts:      files dns

# Example - obey only what nisplus tells us...
#services:   nisplus [NOTFOUND=return] files
#networks:   nisplus [NOTFOUND=return] files
#protocols:  nisplus [NOTFOUND=return] files
#rpc:        nisplus [NOTFOUND=return] files
#ethers:     nisplus [NOTFOUND=return] files
#netmasks:   nisplus [NOTFOUND=return] files     

bootparams: nisplus [NOTFOUND=return] files

ethers:     files
netmasks:   files
networks:   files
protocols:  files
rpc:        files
services:   files

netgroup:   nisplus

publickey:  nisplus

automount:  files nisplus
aliases:    files nisplus

i don't know much about NIS. as i said i'm beginner in linux

chrism01 · 12-20-2012, 01:32 AM

This

Code:

passwd:     files nisplus
shadow:     files nisplus
group:      files nisplus

shows you are likely using nisplus, which is a centralised auth system which means all the file ownerships (user+group) have to be looked up on the central server.
http://www.eng.auburn.edu/~rayh/solaris/NIS+_FAQ.html

Valery Reznic · 12-20-2012, 12:05 PM

Quote:

Originally Posted by chrism01

This

Code:

passwd:     files nisplus
shadow:     files nisplus
group:      files nisplus

shows you are likely using nisplus, which is a centralised auth system which means all the file ownerships (user+group) have to be looked up on the central server.
http://www.eng.auburn.edu/~rayh/solaris/NIS+_FAQ.html

And likely your nisplus server down/very slow.

tonyfreeman · 12-21-2012, 08:54 PM

When this happens to me it is usually because the file system has to be mounted or awakened.

* autofs mounted file systems will have this behavior
* NFS mounted file systems, that are mounted but not attached, will have this same behavior
* file systems accessed via USB will also have this behavior

So ... provide the content of this file: /etc/fstab

And ... what directory are you in when you do the 'ls' command? We can tell from /etc/fstab file if the directory if it is a file system mount issue.