Sunday, September 17, 2017
Thursday, August 10, 2017
How to Find timestamp info in ILOM hostconsole log outputs
As you know there can be a lack of date+time info reported in the ILOM
hostconsole logs during Linux boot, which can make it difficult to know
what info in the console log may be usefully current or irrelevantly old
for the system problem you are investigating, for comparing to System
Event Log time stamps, other OS logs etc.
The 'audit()' entries that are reported when linux boots contain epoch timestamps which we can convert to human-readable date+time.
EG hostconsole.log will show linux reported audit events during boot:
...
type=2000 audit(1436937809.284:1): initialized
type=1404 audit(1436937824.874:2): selinux=0
type=1300 audit(1436937824.874:2): arch=c000003e
...
We can use the unix 'date' command to convert "audit(1436937809.284:1)" to a more useful format:
# date --date="@1436937809"
Wed Jul 15 06:23:29 BST 2015
Or you can use the Epoch converter tool at:
http://www.epochconverter.com/
Note that the audit() epoch times use the local system's timezone, so take that into account when converting eg
# TZ="BST" date --date ...
Source : Friend
Regards
Gurudatta N.R
The 'audit()' entries that are reported when linux boots contain epoch timestamps which we can convert to human-readable date+time.
EG hostconsole.log will show linux reported audit events during boot:
...
type=2000 audit(1436937809.284:1): initialized
type=1404 audit(1436937824.874:2): selinux=0
type=1300 audit(1436937824.874:2): arch=c000003e
...
We can use the unix 'date' command to convert "audit(1436937809.284:1)" to a more useful format:
# date --date="@1436937809"
Wed Jul 15 06:23:29 BST 2015
Or you can use the Epoch converter tool at:
http://www.epochconverter.com/
Note that the audit() epoch times use the local system's timezone, so take that into account when converting eg
# TZ="BST" date --date ...
Source : Friend
Regards
Gurudatta N.R
Friday, July 28, 2017
How to reset the ILOM root password back to the default ‘changeme’ using ipmitool
How to reset the ILOM root password back to the default ‘changeme’ using ipmitool
If the root password on the ILOM is currently unknown, you can change the ILOM password back to the default “changeme”.
# /usr/sbin/ipmitool user set password 0x02 changeme
you can also use the raw format:
# /usr/sbin/ipmitool raw 0x06 0x47 0x02 0x02 0x63 0x68 0x61 0x6e 0x67 0x65 0x6d 0x65 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
Later you can change as per your org standard
-> set /SP/users/root password
Enter new password: ********
Enter new password again: ********
try login with your new root password
Regards
Gurudatta N.R
How to recover the mistakenly deleted/destroyed Zpool.
How to recover the mistakenly deleted/destroyed Zpool.
root@sukhoi:/# zpool destroy fighter =========> mistakenly deleted/destroyed Zpool
To recover the destroyed pool, run the zpool import -D command with the pool to be recovered
root@sukhoi:/# zpool import -D fighter
root@sukhoi:/# zpool status
pool: fighter
state: ONLINE
scan: resilvered 1K in 1s with 0 errors on Tue Jul 25 21:47:54 2017
config:
NAME STATE READ WRITE CKSUM
fighter ONLINE 0 0 0
raidz2-0 ONLINE 0 0 0
c4t0d0 ONLINE 0 0 0
c4t1d0 ONLINE 0 0 0
c4t2d0 ONLINE 0 0 0
c4t3d0 ONLINE 0 0 0
c4t4d0 ONLINE 0 0 0
c4t5d0 ONLINE 0 0 0
c4t6d0 ONLINE 0 0 0
c4t7d0 ONLINE 0 0 0
errors: No known data errors
If one of the devices in the destroyed pool is faulted or unavailable, you might be able to recover the destroyed pool anyway by including the -f option. In this scenario, you would import the degraded pool and then attempt to fix the device failure
Regards
Gurudatta N.R
.
root@sukhoi:/# zpool destroy fighter =========> mistakenly deleted/destroyed Zpool
To recover the destroyed pool, run the zpool import -D command with the pool to be recovered
root@sukhoi:/# zpool import -D fighter
root@sukhoi:/# zpool status
pool: fighter
state: ONLINE
scan: resilvered 1K in 1s with 0 errors on Tue Jul 25 21:47:54 2017
config:
NAME STATE READ WRITE CKSUM
fighter ONLINE 0 0 0
raidz2-0 ONLINE 0 0 0
c4t0d0 ONLINE 0 0 0
c4t1d0 ONLINE 0 0 0
c4t2d0 ONLINE 0 0 0
c4t3d0 ONLINE 0 0 0
c4t4d0 ONLINE 0 0 0
c4t5d0 ONLINE 0 0 0
c4t6d0 ONLINE 0 0 0
c4t7d0 ONLINE 0 0 0
errors: No known data errors
If one of the devices in the destroyed pool is faulted or unavailable, you might be able to recover the destroyed pool anyway by including the -f option. In this scenario, you would import the degraded pool and then attempt to fix the device failure
Regards
Gurudatta N.R
.
Friday, July 21, 2017
Monday, July 10, 2017
How to update the Aspen HBA firmware in Linux.
1) Download the storecli RPM from the following site http://dl.marmotte.net/rpms/redhat/el6/x86_64/storcli-1.16.06-2/
2) Download the HBA firmware from the Aspen/Vendor site. MR_6.3.8.4_24.3.0-0084.rom
3) Ensure there is no issue with the RAID, if the disk is part of the HW raid/
Then run issue the following command .
[root@sukhoisbin]#
storcli /c0 download file=/tmp/MR_6.3.8.4_24.3.0-0084.rom
Download Completed.
Flashing image to adapter...
Controller = 0
Status = Success
Description = F/W Flash Completed. Please reboot the system for the changes to take effect
Current package version = 24.3.0-0063
New package version = 24.3.0-0084
Regards
Gurudatta N.R
2) Download the HBA firmware from the Aspen/Vendor site. MR_6.3.8.4_24.3.0-0084.rom
3) Ensure there is no issue with the RAID, if the disk is part of the HW raid/
Then run issue the following command .
[root@sukhoisbin]#
storcli /c0 download file=/tmp/MR_6.3.8.4_24.3.0-0084.rom
Download Completed.
Flashing image to adapter...
Controller = 0
Status = Success
Description = F/W Flash Completed. Please reboot the system for the changes to take effect
Current package version = 24.3.0-0063
New package version = 24.3.0-0084
Regards
Gurudatta N.R
Saturday, June 24, 2017
Sunday, June 18, 2017
How to fix “FAIL TO LOAD SELINUX POLICY. FREEZING.” ERROR MESSAGE WHILE BOOTING OEL 7.0
Issue reported: You’ve entered a wrong value to the /etc/selinux/config file. After booting the machine, you’re getting
Your System cannot be booted
Work around : on the boot menu, edit the boot configuration and add “selinux=0” to the boot command. In Redhat, it can be done in the following way:
Go to the main command (usually starting with “linux16” or something similar) and add “selinux=0” as one of the parameters:
by pressing CTRL-X on this case and your machine will boot as usual
Tuesday, June 13, 2017
Friday, April 14, 2017
How to verify the IB cards installed in super Cluster.
# prtdiag | egrep "/PCI-EM.+673c" | awk '{print $1, $2, $4}'
/SYS/PCI-EM1 PCIE
/SYS/PCI-EM9 PCIE
Should show an IB card at locations EM1, EM7, EM9, and EM12.
# cfgadm -v | grep -i ib
unavailable IB-HCA n /devices/ib:21280001EF2DFA
unavailable IB-HCA n /devices/ib:21280001EF2EE2
ib connected configured ok InfiniBand Fabric
unavailable IB-Fabric n /devices/ib:fabric
Regards
Gurudatta N.R
Wednesday, April 12, 2017
Monday, February 27, 2017
Intel® 64 and IA-32 Architectures Software Developer Manuals
https://software.intel.com/en-us/articles/intel-sdm
Saturday, February 11, 2017
Diffrence between ext3 and ext4
Features
|
Ext3
|
Ext4
|
Filesystem limit
|
16TB
|
1EB (1 EB = 1024 PB, 1 PB = 1024 TB)
|
File limit
|
2TB
|
16TB
|
Default inode size
|
128 bytes
|
256 bytes
|
Block Mapping
|
Indirect
|
Extent
|
Time Stamp
|
Second
|
Nanosecond
|
Sub Directory Limit
|
32,768
|
Unlimited
|
Preallocation
|
In-core reservation
|
For extent file
|
Defragmentation
|
No
|
Yes
|
Directory Indexing
|
Disabled
|
Enabled
|
Delayed Allocation
|
No
|
Yes
|
Multiple Block Allocation
|
Basic
|
Advanced
|
Regards
Gurudatta N.R
Thursday, January 12, 2017
UFS to ZFS conversion
bash-3.2# uname -a
SunOS Sukhoi 5.10 Generic_147440-01 sun4u sparc SUNW,Sun-Fire-480R
bash-3.2# zpool create rpool c1t1d0s0
invalid vdev specification
use '-f' to override the following errors:
/dev/dsk/c1t1d0s0 is part of exported or potentially active ZFS pool rpool. Please see zpool(1M).
bash-3.2# zpool create -f rpool c1t1d0s0
bash-3.2# zfs list
NAME USED AVAIL REFER MOUNTPOINT
rpool 77.5K 32.7G 31K /rpool
bash-3.2# lustatus
ERROR: No boot environments are configured on this system
ERROR: cannot determine list of all boot environment names
bash-3.2# lucreate -c sol_stage1 -n sol_stage2 -p rpool
Determining types of file systems supported
Validating file system requests
Preparing logical storage devices
Preparing physical storage devices
Configuring physical storage devices
Configuring logical storage devices
Analyzing system configuration.
No name for current boot environment.
Current boot environment is named.
Creating initial configuration for primary boot environment.
INFORMATION: No BEs are configured on this system.
The device
is not a root device for any boot environment; cannot get BE ID.
PBE configuration successful: PBE name PBE Boot Device .
Updating boot environment description database on all BEs.
Updating system configuration files.
The device is not a root device for any boot environment; cannot get BE ID.
Creating configuration for boot environment.
Source boot environment is.
Creating file systems on boot environment.
Creating file system for </> in zone on .
Populating file systems on boot environment.
Analyzing zones.
Mounting ABE.
Generating file list.
Copying data from PBE to ABE .
22% of filenames transferred
100% of filenames transferred
Finalizing ABE.
Fixing zonepaths in ABE.
Unmounting ABE.
Fixing properties on ZFS datasets in ABE.
Reverting state of zones in PBE.
Making boot environment bootable.
Creating boot_archive for /.alt.tmp.b-Vqf.mnt
updating /.alt.tmp.b-Vqf.mnt/platform/sun4u/boot_archive
Population of boot environment successful.
Creation of boot environment successful.
bash-3.2# lustatus
Boot Environment Is Active Active Can Copy
Name Complete Now On Reboot Delete Status
-------------------------- -------- ------ --------- ------ ----------
sol_stage1 yes yes yes no -
sol_stage2 yes no no yes -
bash-3.2# luactivate sol_stage2
**********************************************************************
The target boot environment has been activated. It will be used when you
reboot. NOTE: You MUST NOT USE the reboot, halt, or uadmin commands. You
MUST USE either the init or the shutdown command when you reboot. If you
do not use either init or shutdown, the system will not boot using the
target BE.
**********************************************************************
In case of a failure while booting to the target BE, the following process
needs to be followed to fallback to the currently working boot environment:
1. Enter the PROM monitor (ok prompt).
2. Change the boot device back to the original boot environment by typing:
setenv boot-device
/pci@9,600000/SUNW,qlc@2/fp@0,0/disk@w21000004cffb7f68,0:a
3. Boot to the original boot environment by typing:
boot
**********************************************************************
Modifying boot archive service
Activation of boot environment successful.
Reboot the server with init 6 to boot from new boot environment.
bash-3.2# lustatus
Boot Environment Is Active Active Can Copy
Name Complete Now On Reboot Delete Status
-------------------------- -------- ------ --------- ------ ----------
sol_stage1 yes no no yes -
sol_stage2 yes yes yes no -
bash-3.2# zfs list
NAME USED AVAIL REFER MOUNTPOINT
rpool 6.90G 25.8G 33.5K /rpool
rpool/ROOT 4.38G 25.8G 31K legacy
rpool/ROOT/sol_stage2 4.38G 25.8G 4.38G /
rpool/dump 2.00G 25.8G 2.00G -
rpool/swap 529M 26.4G 16K -
bash-3.2# ludelete -f sol_stage1
Updating boot environment configuration database.
Updating boot environment description database on all BEs.
Updating all boot environment configuration databases.
deleted old boot environment disk for rpool mirroring
bash-3.2# lustatus
Boot Environment Is Active Active Can Copy
Name Complete Now On Reboot Delete Status
-------------------------- -------- ------ --------- ------ ----------
sol_stage2 yes yes yes no -
bash-3.2# zpool status
pool: rpool
state: ONLINE
scan: none requested
config:
NAME STATE READ WRITE CKSUM
rpool ONLINE 0 0 0
c1t1d0s0 ONLINE 0 0 0
errors: No known data errors
bash-3.2# ! format
Searching for disks...done
AVAILABLE DISK SELECTIONS:
0. c1t0d0
/pci@9,600000/SUNW,qlc@2/fp@0,0/ssd@w21000004cffb7f68,0
1. c1t1d0
/pci@9,600000/SUNW,qlc@2/fp@0,0/ssd@w21000004cffb7da9,0
Specify disk (enter its number):
bash-3.2# prtvtoc /dev/rdsk/c1t1d0s2 |fmthard -s - /dev/rdsk/c1t0d0s2
fmthard: New volume table of contents now in place.
bash-3.2# zpool attach rpool c1t1d0s0 c1t0d0s0
invalid vdev specification
use '-f' to override the following errors:
/dev/dsk/c1t0d0s0 contains a ufs filesystem.
bash-3.2# zpool attach -f rpool c1t1d0s0 c1t0d0s0
Make sure to wait until resilver is done before rebooting.
bash-3.2# zpool status
pool: rpool
state: ONLINE
status: One or more devices is currently being resilvered. The pool will
continue to function, possibly in a degraded state.
action: Wait for the resilver to complete.
scan: resilver in progress since Thu Jan 12 05:20:44 2017
1.31G scanned out of 6.38G at 36.4M/s, 0h2m to go
1.31G scanned out of 6.38G at 36.4M/s, 0h2m to go
1.31G resilvered, 20.59% done
config:
NAME STATE READ WRITE CKSUM
rpool ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
c1t1d0s0 ONLINE 0 0 0
c1t0d0s0 ONLINE 0 0 0 (resilvering)
errors: No known data errors
bash-3.2# zpool status
pool: rpool
state: ONLINE
scan: resilvered 6.38G in 0h5m with 0 errors on Thu Jan 12 05:25:59 2017
config:
NAME STATE READ WRITE CKSUM
rpool ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
c1t1d0s0 ONLINE 0 0 0
c1t0d0s0 ONLINE 0 0 0
errors: No known data errors
Regards
Gurudatta N.R
SunOS Sukhoi 5.10 Generic_147440-01 sun4u sparc SUNW,Sun-Fire-480R
bash-3.2# zpool create rpool c1t1d0s0
invalid vdev specification
use '-f' to override the following errors:
/dev/dsk/c1t1d0s0 is part of exported or potentially active ZFS pool rpool. Please see zpool(1M).
bash-3.2# zpool create -f rpool c1t1d0s0
bash-3.2# zfs list
NAME USED AVAIL REFER MOUNTPOINT
rpool 77.5K 32.7G 31K /rpool
bash-3.2# lustatus
ERROR: No boot environments are configured on this system
ERROR: cannot determine list of all boot environment names
bash-3.2# lucreate -c sol_stage1 -n sol_stage2 -p rpool
Determining types of file systems supported
Validating file system requests
Preparing logical storage devices
Preparing physical storage devices
Configuring physical storage devices
Configuring logical storage devices
Analyzing system configuration.
No name for current boot environment.
Current boot environment is named
Creating initial configuration for primary boot environment
INFORMATION: No BEs are configured on this system.
The device
is not a root device for any boot environment; cannot get BE ID.
PBE configuration successful: PBE name
Updating boot environment description database on all BEs.
Updating system configuration files.
The device is not a root device for any boot environment; cannot get BE ID.
Creating configuration for boot environment
Source boot environment is
Creating file systems on boot environment
Creating
Populating file systems on boot environment
Analyzing zones.
Mounting ABE
Generating file list.
Copying data from PBE
22% of filenames transferred
100% of filenames transferred
Finalizing ABE.
Fixing zonepaths in ABE.
Unmounting ABE
Fixing properties on ZFS datasets in ABE.
Reverting state of zones in PBE
Making boot environment
Creating boot_archive for /.alt.tmp.b-Vqf.mnt
updating /.alt.tmp.b-Vqf.mnt/platform/sun4u/boot_archive
Population of boot environment
Creation of boot environment
bash-3.2# lustatus
Boot Environment Is Active Active Can Copy
Name Complete Now On Reboot Delete Status
-------------------------- -------- ------ --------- ------ ----------
sol_stage1 yes yes yes no -
sol_stage2 yes no no yes -
bash-3.2# luactivate sol_stage2
**********************************************************************
The target boot environment has been activated. It will be used when you
reboot. NOTE: You MUST NOT USE the reboot, halt, or uadmin commands. You
MUST USE either the init or the shutdown command when you reboot. If you
do not use either init or shutdown, the system will not boot using the
target BE.
**********************************************************************
In case of a failure while booting to the target BE, the following process
needs to be followed to fallback to the currently working boot environment:
1. Enter the PROM monitor (ok prompt).
2. Change the boot device back to the original boot environment by typing:
setenv boot-device
/pci@9,600000/SUNW,qlc@2/fp@0,0/disk@w21000004cffb7f68,0:a
3. Boot to the original boot environment by typing:
boot
**********************************************************************
Modifying boot archive service
Activation of boot environment
Reboot the server with init 6 to boot from new boot environment.
bash-3.2# lustatus
Name Complete Now On Reboot Delete Status
-------------------------- -------- ------ --------- ------ ----------
sol_stage1 yes no no yes -
sol_stage2 yes yes yes no -
bash-3.2# zfs list
NAME USED AVAIL REFER MOUNTPOINT
rpool 6.90G 25.8G 33.5K /rpool
rpool/ROOT 4.38G 25.8G 31K legacy
rpool/ROOT/sol_stage2 4.38G 25.8G 4.38G /
rpool/dump 2.00G 25.8G 2.00G -
rpool/swap 529M 26.4G 16K -
bash-3.2# ludelete -f sol_stage1
Updating boot environment configuration database.
Updating boot environment description database on all BEs.
Updating all boot environment configuration databases.
deleted old boot environment disk for rpool mirroring
bash-3.2# lustatus
Boot Environment Is Active Active Can Copy
Name Complete Now On Reboot Delete Status
-------------------------- -------- ------ --------- ------ ----------
sol_stage2 yes yes yes no -
bash-3.2# zpool status
pool: rpool
state: ONLINE
scan: none requested
config:
NAME STATE READ WRITE CKSUM
rpool ONLINE 0 0 0
c1t1d0s0 ONLINE 0 0 0
errors: No known data errors
bash-3.2# ! format
Searching for disks...done
AVAILABLE DISK SELECTIONS:
0. c1t0d0
/pci@9,600000/SUNW,qlc@2/fp@0,0/ssd@w21000004cffb7f68,0
1. c1t1d0
/pci@9,600000/SUNW,qlc@2/fp@0,0/ssd@w21000004cffb7da9,0
Specify disk (enter its number):
bash-3.2# prtvtoc /dev/rdsk/c1t1d0s2 |fmthard -s - /dev/rdsk/c1t0d0s2
fmthard: New volume table of contents now in place.
bash-3.2# zpool attach rpool c1t1d0s0 c1t0d0s0
invalid vdev specification
use '-f' to override the following errors:
/dev/dsk/c1t0d0s0 contains a ufs filesystem.
bash-3.2# zpool attach -f rpool c1t1d0s0 c1t0d0s0
Make sure to wait until resilver is done before rebooting.
bash-3.2# zpool status
pool: rpool
state: ONLINE
status: One or more devices is currently being resilvered. The pool will
continue to function, possibly in a degraded state.
action: Wait for the resilver to complete.
scan: resilver in progress since Thu Jan 12 05:20:44 2017
1.31G scanned out of 6.38G at 36.4M/s, 0h2m to go
1.31G scanned out of 6.38G at 36.4M/s, 0h2m to go
1.31G resilvered, 20.59% done
config:
NAME STATE READ WRITE CKSUM
rpool ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
c1t1d0s0 ONLINE 0 0 0
c1t0d0s0 ONLINE 0 0 0 (resilvering)
errors: No known data errors
bash-3.2# zpool status
pool: rpool
state: ONLINE
scan: resilvered 6.38G in 0h5m with 0 errors on Thu Jan 12 05:25:59 2017
config:
NAME STATE READ WRITE CKSUM
rpool ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
c1t1d0s0 ONLINE 0 0 0
c1t0d0s0 ONLINE 0 0 0
errors: No known data errors
Regards
Gurudatta N.R
How to Label Multiple Disks by Using the prtvtoc and fmthard Commands.
Labeling Multiple Disks by Using the prtvtoc and fmthard Commands
Use the prtvtoc and fmthard commands to label multiple disks with the same disk geometry.
Use the following for loop in a script to copy a disk label from one disk and replicate it on multiple disks.
# for i in x y z
> do
> prtvtoc /dev/rdsk/cwtxdysz | fmthard -s - /dev/rdsk/cwt${i}d0s2
> done
Example 11–9 Labeling Multiple Disks
In this example, the disk label from c2t0d0s0 is copied to four other disks.
# for i in 1 2 3 5
> do
> prtvtoc /dev/rdsk/c2t0d0s0 | fmthard -s - /dev/rdsk/c2t${i}d0s2
> done
fmthard: New volume table of contents now in place.
fmthard: New volume table of contents now in place.
fmthard: New volume table of contents now in place.
fmthard: New volume table of contents now in place.
Regards
Gurudatta N.R
Use the prtvtoc and fmthard commands to label multiple disks with the same disk geometry.
Use the following for loop in a script to copy a disk label from one disk and replicate it on multiple disks.
# for i in x y z
> do
> prtvtoc /dev/rdsk/cwtxdysz | fmthard -s - /dev/rdsk/cwt${i}d0s2
> done
Example 11–9 Labeling Multiple Disks
In this example, the disk label from c2t0d0s0 is copied to four other disks.
# for i in 1 2 3 5
> do
> prtvtoc /dev/rdsk/c2t0d0s0 | fmthard -s - /dev/rdsk/c2t${i}d0s2
> done
fmthard: New volume table of contents now in place.
fmthard: New volume table of contents now in place.
fmthard: New volume table of contents now in place.
fmthard: New volume table of contents now in place.
Regards
Gurudatta N.R
Wednesday, December 28, 2016
Friday, October 14, 2016
Linux Signals
| Signal | Name | Description |
|---|---|---|
| SIGHUP | 1 | Hangup (POSIX) |
| SIGINT | 2 | Terminal interrupt (ANSI) |
| SIGQUIT | 3 | Terminal quit (POSIX) |
| SIGILL | 4 | Illegal instruction (ANSI) |
| SIGTRAP | 5 | Trace trap (POSIX) |
| SIGIOT | 6 | IOT Trap (4.2 BSD) |
| SIGBUS | 7 | BUS error (4.2 BSD) |
| SIGFPE | 8 | Floating point exception (ANSI) |
| SIGKILL | 9 | Kill(can't be caught or ignored) (POSIX) |
| SIGUSR1 | 10 | User defined signal 1 (POSIX) |
| SIGSEGV | 11 | Invalid memory segment access (ANSI) |
| SIGUSR2 | 12 | User defined signal 2 (POSIX) |
| SIGPIPE | 13 | Write on a pipe with no reader, Broken pipe (POSIX) |
| SIGALRM | 14 | Alarm clock (POSIX) |
| SIGTERM | 15 | Termination (ANSI) |
| SIGSTKFLT | 16 | Stack fault |
| SIGCHLD | 17 | Child process has stopped or exited, changed (POSIX) |
| SIGCONTv | 18 | Continue executing, if stopped (POSIX) |
| SIGSTOP | 19 | Stop executing(can't be caught or ignored) (POSIX) |
| SIGTSTP | 20 | Terminal stop signal (POSIX) |
| SIGTTIN | 21 | Background process trying to read, from TTY (POSIX) |
| SIGTTOU | 22 | Background process trying to write, to TTY (POSIX) |
| SIGURG | 23 | Urgent condition on socket (4.2 BSD) |
| SIGXCPU | 24 | CPU limit exceeded (4.2 BSD) |
| SIGXFSZ | 25 | File size limit exceeded (4.2 BSD) |
| SIGVTALRM | 26 | Virtual alarm clock (4.2 BSD) |
| SIGPROF | 27 | Profiling alarm clock (4.2 BSD) |
| SIGWINCH | 28 | Window size change (4.3 BSD, Sun) |
| SIGIO | 29 | I/O now possible (4.2 BSD) |
| SIGPWR | 30 | Power failure restart (System V) |
What is dig ?
We use the dig (domain information groper) command to query Domain Name System (DNS) name servers.
When we pass a domain name to the dig command, by default, it displays the A record (the ip-address of the site that is queried) as shown below:
Gurudattas-MBP:~ gnadig$ dig google.com
; <<>> DiG 9.8.3-P1 <<>> google.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- 13916="" id:="" noerror="" opcode:="" query="" span="" status:="">
;; flags: qr rd ra; QUERY: 1, ANSWER: 6, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;google.com. IN A
;; ANSWER SECTION:
google.com. 54 IN A 74.125.200.138
google.com. 54 IN A 74.125.200.100
google.com. 54 IN A 74.125.200.101
google.com. 54 IN A 74.125.200.139
google.com. 54 IN A 74.125.200.102
google.com. 54 IN A 74.125.200.113
;; Query time: 5 msec
;; SERVER: 192.168.1.1#53(192.168.1.1)
;; WHEN: Fri Oct 14 15:51:42 2016
;; MSG SIZE rcvd: 124
Regards
Gurudatta N.R
Thursday, October 13, 2016
Identifying a Hard Disk Using hdparm in linux
# hdparm -I /dev/sd?|grep -E "Number|/dev"
/dev/sda:
Model Number: HDS722516VLSA80
Serial Number: VN6D3ECDD7RG1D
/dev/sdb:
Model Number: WDC WD740GD-00FLA1
Serial Number: WD-WMAKE1690676
/dev/sdc:
Model Number: HDS722525VLSA80
Serial Number: VN6J3ECFEALJRD
/dev/sdd:
Model Number: HDS722525VLSA80
Serial Number: VN6J3ECFEBSR1D
Source Net
Regards
Gurudatta N.R
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