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February, 2015Archive for

remotely eject tap from server

Thursday, February 26th, 2015

use the following command to remotely eject the tap from a tap device to minimize your time & safe your data:

#mt offline

it will eject the tap from the default device tap unit “rmt0”.

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list mksysb from tap

Thursday, February 26th, 2015

try this command to list files from a mksysb tap:

#lsmksysb

the previous command will list from the default tap device “rmt0”.

if you have another tap, try the following:

#lsmksysb -f /dev/rmt5

rename a device

Thursday, February 19th, 2015

Use the following command to rename a device:

# rendev -l hdisk4 -n hdisk53

where the ‘hdisk4’ is your device and ‘hdisk53’ is the new name.

HINT: The device must be free

Error Report Demon

Thursday, February 19th, 2015

Here are the commands related to error demon in AIX

To stop logging run the below command

#/usr/lib/errstop

To get rid of that log.

# rm /var/adm/ras/errlog

To restart the daemon, thus creating a new error log
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Volume Group Status Area (VGSA)

Friday, February 13th, 2015

Information about which PPs that are stale and which PVs are missing within a VG. The LVM and SCSI driver reserves somewhere between 7-10% of the available disk space for LVM maps, etc.

Ref:

http://www.datadisk.co.uk/html_docs/hp/aix_lvm.htm

Volume Group Descriptor Area (VGDA)

Friday, February 13th, 2015

Information about all the LVs and PVs within a VG. The first 64K of a PV is reserved for this area – defined in <sys/bootrecord.h>.

The VGDA consists of

  • BOOTRECORD: – first 512 bytes. Allows the Read Only System (ROS) to boot system
  • BAD BLK DIRECTORY – found in <sys/bddir.h>
  • LVM RECORD – found in <lvmrec.h>

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Volume Group Characteristics

Friday, February 13th, 2015

You can find below the meaning of each parameter on Volume Group Characteristics (the output from lsvg vg command):

 

  1. Volume Group: Name of Volume Group.
  2. VG State: active/partial. Partial indicates that some of the Physical Volumes in the Volume Group are not active.
  3. VG Permission: It indicates if the volume group is read-only or read-write.
  4. Max LVs: Maximum number of Logical Volumes allowed in Volume Group.
  5. LVs: Total number of Logical Volumes at present in Volume Group.
  6. Open LVs: Number of LVs open at present in the Volume Group for any Read Write operation.
  7. Total PVs: Total number of Physical Volumes present in Volume Group.
  8. Stale PVs: How many stale Physical Volumes are there in Volume Group. The stale Physical Volumes are those ones on which I/O operations are not possible.
  9. Active PVs: Total number of Physical Volumes which are active in Volume Group.
  10. Max PPs per VG: Maximum no. of Physical Partitions which can be there in the Volume Group.
  11. Max PPs per PV: Maximum number of Physical Partitions which can be there in Physical Volume.
  12. VG Identifier: The very long string to identify Volume Group.
  13. PP Size: The size of Physical Partition used in every Physical Volume of Volume Group.
  14. Total PPs: Total number of Physical Partitions in Volume Group.
  15. Free PPs: Total number of free Physical Partitions with in Volume Group.
  16. Used PPs: Total number of Physical Partitions in use in Volume Group.
  17. Quorum: Whether the quorum is on or not in Volume Group.
  18. VG Descriptors: Number of Volume Group Descriptor Areas(VGDA) in Volume Group.
  19. Stale PPs: How many Physical Partitions are stale or unable to perform I/O operations.
  20. Auto On: Whether the Volume Group will varyon on system startup or not.
  21. Max PVs: Maximum number of Physical Volumes allowed in this Volume Group.
  22. Auto Sync: Whether this Volume Group should sync automatically or not.
  23. BB Policy: Its bad block relocation policy. So, this value here is relocatable, that means we are allowed to relocate bad blocks in this Volume Group if need be.

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en vs et vs ent

Monday, February 9th, 2015

most of us has  confused between the network devices en, et & ent, you can read the following to put a limit for this confusion 🙂 :

ent:
The notation ent is used to specify the hardware adapter. It has nothing to do with the TCP/IP address.

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