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
Here are the commands related to error demon in AIX
To stop logging run the below command
To get rid of that log.
# rm /var/adm/ras/errlog
To restart the daemon, thus creating a new error log
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.
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>
You can find below the meaning of each parameter on Volume Group Characteristics (the output from lsvg vg command):
- Volume Group: Name of Volume Group.
- VG State: active/partial. Partial indicates that some of the Physical Volumes in the Volume Group are not active.
- VG Permission: It indicates if the volume group is read-only or read-write.
- Max LVs: Maximum number of Logical Volumes allowed in Volume Group.
- LVs: Total number of Logical Volumes at present in Volume Group.
- Open LVs: Number of LVs open at present in the Volume Group for any Read Write operation.
- Total PVs: Total number of Physical Volumes present in Volume Group.
- 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.
- Active PVs: Total number of Physical Volumes which are active in Volume Group.
- Max PPs per VG: Maximum no. of Physical Partitions which can be there in the Volume Group.
- Max PPs per PV: Maximum number of Physical Partitions which can be there in Physical Volume.
- VG Identifier: The very long string to identify Volume Group.
- PP Size: The size of Physical Partition used in every Physical Volume of Volume Group.
- Total PPs: Total number of Physical Partitions in Volume Group.
- Free PPs: Total number of free Physical Partitions with in Volume Group.
- Used PPs: Total number of Physical Partitions in use in Volume Group.
- Quorum: Whether the quorum is on or not in Volume Group.
- VG Descriptors: Number of Volume Group Descriptor Areas(VGDA) in Volume Group.
- Stale PPs: How many Physical Partitions are stale or unable to perform I/O operations.
- Auto On: Whether the Volume Group will varyon on system startup or not.
- Max PVs: Maximum number of Physical Volumes allowed in this Volume Group.
- Auto Sync: Whether this Volume Group should sync automatically or not.
- 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.
most of us has confused between the network devices en, et & ent, you can read the following to put a limit for this confusion 🙂 :
The notation ent is used to specify the hardware adapter. It has nothing to do with the TCP/IP address.
We can divide IT systems into transactional (OLTP) and analytical (OLAP). In general we can assume that OLTP systems provide source data to data warehouses, whereas OLAP systems help to analyze it.
OLAP (online analytical processing): is computer processing that enables a user to easily and selectively extract and view data from different points of view.
For example, a user can request that data be analyzed to display a spreadsheet showing all of a company’s beach ball products sold in Florida in the month of July, compare revenue figures with those for the same products in September, and then see a comparison of other product sales in Florida in the same time period.
OLTP ( Online transaction processing) : is a class of information systems that facilitate and manage transaction-oriented applications, typically for data entry and retrieval transaction processing.
LVM :- Logical Volume Manager and it’s a disk Management for Linux/UNIX Systems.