LINUX_GENERAL.md

Generate Javacore

Get PID

watch "ps -eo pcpu,pid,user,args | sort -k 1 -r | head -6" 

or

cat /opt/WebSphere/AppServer/profiles/AppSrv01/logs/WC_stgmall1/WC_stgmall1.pid

Genearte javacore

kill -3 PID

grep a string out of files printing only the file name

grep -H "<ErrorMessage>" SystemOut*.log -R | cut -d: -f1

Check global file write permission security

for PART in `awk '(!/^#/ && $6 != "0") { print $2 }' /etc/fstab 2>/dev/null`; do find $PART -xdev -type f \( -perm -0002 -a ! -perm -1000 \) -print 2>/dev/null; done

check large file

find . -type f -size +50000k -exec ls -lh {} \; | awk '{ print $9 ": " $5 }'

extension

change from one to another

for f in *.php4; do mv $f `basename $f .php4`.php; done;

for f in *; do mv $f `basename $f `.txt; done;

remove

for f in *.txt; do mv $f `basename $f .txt`; done;

AIX

tar -cvf - /some/directory/path/ | gzip -c | split -b 500m - file.tgz.

fine and sort

find -type f -print0 | xargs -r0 stat -c %y\ %n | sort

find file newer than another file and cp

find . -name "*.xml" -newer SKU_1408619449286_557746.xml -exec cp {} /data/full_local/ \;

find archive and list files

find . -name "daily_archive.20140*.gz" -exec tar ztvf {} \; > /tmp/find.log

Check RHEL release

cat /etc/redhat-release

Run Level

chkconfig –-list | grep 5:on
chkconfig <Service-Name> on –level 3

Kernel parameters

/etc/sysctl.conf
sysctl -p

NFS

server

yum install nfs-utils nfs-utils-lib
chkconfig nfs on 
service rpcbind start
service nfs start
vi /etc/exports   # add /home 12.33.44.555(rw,sync,no_root_squash,no_subtree_check)
exportfs -a

client

yum install nfs-utils nfs-utils-lib
mkdir -p /mnt/nfs/home
mount 12.34.56.789:/home /mnt/nfs/home
df -h # validate or use mount

alais

alias ll='ls -al'

Allocate additional disk

mkfs -t ext4 /dev/xvdc
echo "/dev/xvdc /mount_name ext4 defaults 0 0" >> /etc/fstab # /dev/sda /data ext4 _netdev 0 0
mkdir -p /mount_name
mount /mount_name

chage

chage -E -1 -I -1 -M 99999 -m 0 deploy