Thursday, December 13, 2007

Solaris Faq

What is the command to do an interactive boot from the ok promt?
boot -i

How can i disable STOP+A utility on SUN machines,
which brings system into OK> prompt???.
In /etc/system set abort_enable=0 will disable STOP-A

Where are the templates stored that are copied into the user's home
directories for their personal customizations?

What SPARC emergency keyboard sequence will take
the system to the ok prompt (forth monitor) but will send output to TTYA?

What file controls system wide password aging?

What flag used with patchadd will prevent a later back out by
preventing patchadd from backing up files? If this flag is used,
the patch cannot be removed.
patchadd -d

What file do you put the umask setting in?
The UMASK value for bourne and korn shell users can
be modified system wide by editing the "umask" entry in the
"/etc/profile" file. To change the default UMASK for the C shell,
modify the UMASK variable in "/etc/default/login" file.

Which of the following commands can tell you whether
packets are being delayed or dropped on your network?
% spray -c 100 -d 20 0 -l 2048 pluto
The following example sends 100 packets to a host (-c 100)
with each packet having a size of 2048 bytes (-l 2048). The packets
are sent with a delay time of 20 microseconds between
each burst (-d 20). If you don't use a delay, you may run out of buffers.

Partition sizes can be set manually or from what configuration?

Give the command that will display your default boot device.
eeprom boot-device & not printenv as suggested

How many different kill signals are there?

What software install group do you need to select in order to load the compilers?
End User System Support Software Group (SUNWCuser)
Developer System Support Software Group (SUNWCprog)

What command can you use to display all of your groups?
groups - To display full list
id -a - To diaplsy full list of groups with group id numbers

What does this file /etc/path_to_inst contain and what is the
importance of this file
/etc/path_to_inst contains each device,
its instance name and number along with its physical name.

What is the command can reconfigure devices with out reboot?
devfsadm - solaris 8 onwards

How to restore a corrupted file sytem or trouble shoot bad
super blocks for a FS c0t2d0s5 ?
Well you can also just use the #FSCK -N /dev.dsk/c0t2d0s5
to get the back up block number and then using one of the numbers
that display #FSCK -F ufs -o b=32 can be executed.

How will you add a virtual IP address to a server. Given the interface
qe0 and IP
# ifconfig qe0:1 up
where "qe0" is an interface (e.g., le0) and N is a number between 1 and
. Removing the pseudo interface and associated address is done
with "ifconfig qe0:1 down".
As with physical interfaces, all you need to do is make the
appropriate /etc/hostname.qe0:X file.

Boot phases of Solaris Operating Environment are:
1.boot PROM
2.boot programs like bootblk,ufsboot
3.kernel initialization like loading modules
4. init phase

How do you determin which Run Level the sytem is running
who -r

How would you find out what version of Solaris is currently running?
Run the command showrev. There's a man page on showrev and
there are switches to help you do whatever you're trying to do

As a system administrator, how would you figure out the system
transaction is slow between the system you logged into and from the system you did telnet login?

# Display the parent/child tree of a process ?
- ptree Example: ptree 1267

# Show the working directory of a process ?
- pwdx Example: pwdx 1267

# Display the processes current open files ? -
pfiles Example: pfiles 1267

Alternative for top command ? -
prstat -a

Sunday, December 09, 2007

Listing USB devices on Fedora 7

lsusb command can list all usb devices found,
I had Fedora core 7(moonshine) installed and i did not find the command,

I had to install usbutils which brings the command:

[root@linuxbox ~]# yum -y install usbutils
Installed: usbutils.i386 0:0.71-2.1

[root@linuxbox ~]# lsusb
Bus 004 Device 001: ID 0000:0000
Bus 003 Device 001: ID 0000:0000
Bus 002 Device 001: ID 0000:0000
Bus 001 Device 001: ID 0000:0000
Bus 001 Device 004: ID 07a6:8511 ADMtek, Inc. ADM8511 Pegasus II Ethernet
Bus 001 Device 003: ID 046d:c016 Logitech, Inc. M-UV69a Optical Wheel Mouse

[root@linuxbox ~]# lsusb -d 07a6:8511 -v <--- gives details
Bus 001 Device 004: ID 07a6:8511 ADMtek, Inc. ADM8511 Pegasus II Ethernet
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 1.10
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 8
idVendor 0x07a6 ADMtek, Inc.
idProduct 0x8511 ADM8511 Pegasus II Ethernet
bcdDevice 1.01
iManufacturer 1 ADMtek
iProduct 2 USB To LAN Converter
iSerial 3 0001
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 39
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xa0
Remote Wakeup
MaxPower 160mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 3
bInterfaceClass 0 (Defined at Interface level)
bInterfaceSubClass 0
bInterfaceProtocol 0
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0008 1x 8 bytes
bInterval 1

SSH Tips

Pointing to some SSH tips given in Linux Magazine:

$ssh -T user@hostname

If you connect to a host this way, it will disable pseudo-tty allocation
and a command like w will not show your connection. Better add
`bash -i' , as below.
$ssh -T user@hostname /bin/bash -i

With the below command the IP address of the system you connect to wont be
logged into known_hosts file, usually its in /root/.ssh/known_hosts.

$ssh -o UserknownHostsFile=/dev/null -T user@hostname /bin/bash -i

Monday, November 19, 2007

Linux keyboard shortcuts.

Linux has many keyboard shortcuts. Knowing them makes using Linux much easier.


  • Ctrl-Alt-Delete - shuts down computer
  • Alt-Fn (F1, F2, F3,…) - switch to n-th console
  • Alt-Left or Alt-Right - switch to next/previous virtual terminal
  • Scroll Lock - locks terminal input/output - allows to read console contents when output is going too fast. To unlock, press Scroll Lock once again.
    Alternatively, Scroll Lock can be enabled using Ctrl-S and disabled with Ctrl-Q. Try last shortcut if your console hangs for unknown reason - it happened to me many times that I’ve locked it accidentaly by pressing CTRL-S.
  • Shift-Page Up and Shift-Page Down - scrolls console buffer up/down. Works also when Scroll Lock is enabled. After changing the terminal (Alt-Fn) buffer contents is erased and it is impossible to scroll it.
  • Ctrl-L - screen refresh
  • Ctrl-C or Ctrl-Backslash - kills current task
  • Ctrl-D - stands for EOF (End-of-file). If you type it on en empty command line, it will quit bash. This is so much faster than typing exit
  • Ctrl-Z - pause process. Use commands: bg to run in background or fg to run in foreground.

Bash & command-line

  • Ctrl-A - moves cursor to beginning of command line.
  • Ctrl-E - moves cursor to end of command line.
  • Ctrl-K - clears command line from cursor position to end of line.
  • Ctrl-U - clears command line from cursor position to beginning of line.
  • Ctrl-W - clears word to the left
  • Ctrl-Y - will paste in anything that was deleted by Ctrl-U or Ctrl-K or Ctrl-W
  • Tab - command-line autocompletion. Automatically completes current command line.
    If autocompletion script is enabled, then also options and applications parameters are autocompleted.
  • Ctrl-R - followed by characters will do a incremental search of the previous command history

Kernel shortcuts

Following shortcuts must be enabled in kernel, they also must be enabled using proc interface (echo 1 > /proc/sys/kernel/sysrq).

  • Alt-SysRQ-S - sync all mounted filesystem. Data in buffers is immediately written to disks.
  • Alt-SysRQ-U - remounts mounted filesystems read-only
  • Alt-SysRQ-B - performs immediate reboot. Don’t do it without syncing and unmounting as it can cause massive filesystem corruption
  • Alt-SysRQ-S, then Alt-SysRQ-U, then Alt-SysRQ-B - attempts to sync all mounted filesystems, remounts them read-only and immediately reboots computer. Fastest way to reboot Linux.
  • Alt-SysRQ-H - prints out list of other SysRQ functions.

X-Windows shortcuts

  • Ctrl-Alt-Plus or Ctrl-Alt-Minus- changes screen resolution (higher/lower). Only if X-Windows server is configured for multiple resolutions.
  • Ctrl-Alt-Backspace - kill X-server. Running applications will be terminated.
  • Ctrl-Alt-Escape - xkill - click an application to kill it.
  • Ctrl-Shift-Num Lock will turn the keypad on the keyboard into the mouse, so you can control the mouse from keyboard. Keys / and * on the numpad select left mouse click and right mouse click respectively. Mouse click is done by 5 on the numpad.
  • Ctrl-Alt-Fn (F1, F2, F3,…) - switches to n-th text console.

KDE shortcuts

  • Ctrl-Alt-Shift-Page Down - direct shutdown
  • Ctrl-Alt-Shift-Page Up - direct reboot
  • Alt-F2 - Starts the run command box. Type a application executable to launch it, folder name to open it, filename to use an appropriate program to launch it, url to go to it in konqueror and any of the numerous web shortcuts(gg, wp) defined by konqueror to activate them.

Do you know any other shortcuts that are worth to know?