Linux Commands
How verify integrity of password files
How to verify the integrity of the group file
How to check information regarding LVM
How do i display info regarding all TCP/IP sockets in operation currently
Backup to tape drive /dev/st0
Following command to backup the /webroot directory and its content to /dev/st0 with 256 blocking factor:
# tar cvf -b 256 /dev/st0 /webroot
-b, --blocking-factor N
use record size of Nx512 bytes (default N=20)
Using cdrecord
- cdrecord -scanbus
- cdrecord -v speed=2 dev=0,0,0 -data cdimage.iso (The CD writer is the device labeled '0,0,0')
Making ISO images
mkisofs -r -o output_cd_image data_on_HDD (then use cdrecord to write output_cd_image to a CD)
Finding out the disk usage for a partition or dir du - estimate file space usage
du -hm --max-depth 1
How to Monitor the services that is using up most of the cpu and memory on a server.
ps auxfw|sort -nr|grep -v 0.0
[root@wordsworth ~]# ps auxfw|sort -nr|grep -v 0.0
USER PID MEM VSZ RSS TTY STAT START TIME COMMAND
linux 613 0.4 3.2 21844 15896 ? S 15:01 0:10 wish /usr/bin/amsn
linux 4085 0.1 1.7 28384 8240 ? S Mar01 13:45 /usr/libexec/wnck-applet --oaf-
linux 32728 1.8 7.5 67216 36196 ? S 14:54 0:50 /usr/lib/opera/9.10-20061214.5/
linux 31458 0.1 1.0 48068 5088 ? Sl 12:26 0:15 xmms -e
linux 30276 0.6 4.4 79656 21488 ? Sl 07:55 3:09 skype
linux 30261 3.0 18.8 221380 90792 ? Sl 07:54 14:15 \_ /home/linux/firefox/firefox-
linux 30099 0.1 4.5 123240 21776 ? Sl 07:25 0:54 \_ /usr/lib/
linux 2285 0.1 2.6 35504 12560 ? S Mar06 3:06 gaim
root@server16 [~]# ps auxfw|grep -vE '0.0|0.1'How verify integrity of password files
We can use the command below to verify the integrity of the password file.
shibu@shibu-laptop:~$ apropos pwck
pwck (8)- verify integrity of password files
shibu@shibu-laptop:~$ sudo pwck /etc/passwd [sudo] password for shibu: user lp: directory /var/spool/lpd does not exist user news: directory /var/spool/news does not exist user uucp: directory /var/spool/uucp does not exist user www-data: directory /var/www does not exist user list: directory /var/list does not exist user irc: directory /var/run/ircd does not exist user gnats: directory /var/lib/gnats does not exist user nobody: directory /nonexistent does not exist user dhcp: directory /nonexistent does not exist user syslog: directory /home/syslog does not exist user klog: directory /home/klog does not exist user hplip: directory /var/run/hplip does not exist user haldaemon: directory /home/haldaemon does not exist pwck: no changes shibu@shibu-laptop:~$
How to verify the integrity of the group file
shibu@shibu-laptop:~$ apropos grpck
grpck (8)- verify integrity of group files
How to check information regarding LVM
- resize2fs (8) - ext2/ext3 file system resizer: resize2fs /dev/mynew_vg/vol01
- pvcreate (8) - initialize a disk or partition for use by LVM : pvcreate /dev/sdb1
- pvdisplay (8) - display attributes of a physical volume: pvdisplay
- vgcreate (8) - create a volume group: vgcreate mynew_vg /dev/sdb1 , vgcreate mynew_vg /dev/sdb1 /dev/sdb2
- vgextend (8) - add physical volumes to a volume group : vgextend mynew_vg /dev/sdb2
- lvcreate (8) - create a logical volume in an existing volume group:
- vgdisplay (8) - display attributes of volume groups
- create a logical volume of size 400 MB -L 400 : lvcreate -L 400 -n vol01 mynew_vg
- create a logical volume of size 4 GB -L 4G : lvcreate -L 4000 -n vol02 mynew_vg
- mke2fs (8) - create an ext2/ext3 filesystem
- mke2fs [mkfs] (8) - create an ext2/ext3 filesystem
- mke2fs - create an ext2/ext3 filesystem : mkfs.ext3 /dev/mynew_vg/vol01
How to find processor related stats
mpstat
[linux@wordsworth ~]$ man -k mpstat mpstat (1) - Report processors related statistics snmpstatus (1) - Retrieves important information from a network entity [linux@wordsworth ~]$ [linux@wordsworth ~]$ mpstat 5 Linux 2.6.9-55.0.2.ELsmp (wordsworth.armialocal.com) 08/12/2007 09:59:51 PM CPU nice iowait soft %idle intr/s 09:59:56 PM all 18.70 0.10 42.50 0.00 0.10 0.00 38.60 1290.60 10:00:01 PM all 15.30 0.00 41.80 0.00 0.10 0.00 42.80 1276.00 10:00:06 PM all 19.98 0.00 42.36 0.20 0.00 0.00 37.46 1273.35
vmstat
[linux@wordsworth ~]$ man -k vmstat
vmstat (8) - Report virtual memory statistics
linux@wordsworth ~]$
[linux@wordsworth ~]$ vmstat 2
procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
2 0 355084 20888 10736 84396 1 1 37 29 11 13 10 22 67 1
1 0 355084 20936 10736 84396 0 0 0 0 1284 1191 10 42 48 0
3 0 355084 19848 10736 84396 0 0 0 0 1246 1123 9 44 47 0How do i display info regarding all TCP/IP sockets in operation currently
Use the command netstat
netstat -a
usage: netstat [-veenNcCF] [] -r netstat {-V|--version|-h|--help}
netstat [-vnNcaeol] [ ...]
netstat { [-veenNac] -i | [-cnNe] -M | -s }
-r, --route display routing table
-i, --interfaces display interface table
-g, --groups display multicast group memberships
-s, --statistics display networking statistics (like SNMP)
-M, --masquerade display masqueraded connections
-v, --verbose be verbose
-n, --numeric don't resolve names
--numeric-hosts don't resolve host names
--numeric-ports don't resolve port names
--numeric-users don't resolve user names
-N, --symbolic resolve hardware names
-e, --extend display other/more information
-p, --programs display PID/Program name for sockets
-c, --continuous continuous listing
-l, --listening display listening server sockets
-a, --all, --listening display all sockets (default: connected)
-o, --timers display timers
-F, --fib display Forwarding Information Base (default)
-C, --cache display routing cache instead of FIB 
ليست هناك تعليقات:
إرسال تعليق