Posts Tagged ‘LVM’

Useful Commands for Redhat LVM and increasing Filesystem

– Scan New Hardware:
scsi-rescan
rescan-scsi-bus.sh –forcerescan

– For Physical Volumes:
pvdisplay
pvscan
pvcreate /dev/sdb

– For Volume Groups:
vgdisplay
vgscan
vgextend VGNAME PVNAME
lvextend -L+50G LVNAME
resize2fs LVNAME

Volume Group Status Area (VGSA)

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)

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>

LVM

LVM :- Logical Volume Manager and it’s a disk Management for Linux/UNIX Systems.