Table of Contents:

• disk
  • scsi
    • lsscsi
      • ubuntu
      • centos
    • list scsi devices
    • list scsi hosts
    • rescan scsi
    • remove disk from sci
  • fdisk
    • list
    • format and partition
  • mount new disk using the mount command
  • LVM
    • install on ubuntu
    • install on centos
    • enable
    • pv ( LVMs physical volume )
      • create
      • list , display
    • vg (volume group)
      • create vg
      • list VGs or get vg details
    • lv ( logical volume )
      • create lv in existing vg
      • Display

disk

scsi

lsscsi

ubuntu

cat /proc/scsi/scsi

centos

yum install lsscsi

list scsi devices

cat /proc/scsi/scsi

list scsi hosts

ls /sys/class/scsi_host

rescan scsi

echo "- - -" > /sys/class/scsi_host/host#/scan
fdisk -l
tail -f /var/log/message

remove disk from sci

echo 1 > /sys/block/sdc/device/delete

fdisk

list

fdisk -l

format and partition

fdisk /dev/sdx

options :

• n – create a new partition
• p – print the partition table
• can specify size , start and endpoint
• d – delete a partition
• w – write the new partition table and exit
• q – quit without saving changes

  mount new disk using the mount command

  mkdir /disk1
  mount /dev/sdx /disk1
  df -H
  

• mount automaticaly on reboot ( add to /etc/fstab)

  /dev/sdx               /disk1           ext3    defaults        1 2
  

  LVM

  install on ubuntu

  apt install lvm2
  

  install on centos

  yum install lvm2*
  

enable

systemctl enable lvm2-lvmetad.service
systemctl enable lvm2-lvmetad.socket
systemctl start lvm2-lvmetad.service
systemctl start lvm2-lvmetad.socket

pv ( LVMs physical volume )

create

pvcreate used to prepare a disk partition or a whole disk for use by LVM

pvcreate /dev/sd

list , display

To get LVM's internal view and details, use LVM commands Lists : use the lvs and pvs commands with option --segments Detailed view: use the lvdisplay and pvdisplay commands with option -m 1- lvs

• List the physical segments used by a logical volume :

  lvs --segments /dev/vg_ssd/lv_videos -o +lv_size,devices
  

• List the physical extents of a given LV. Useful to move those segments (using pvmove):

  lvs  /dev/vg_ssd/lv_videos -o seg_pe_ranges
  

  3- lvdisplay
• List the physical segments of a given logical volume, among other information:

  lvdisplay -m /dev/vg_ssd/lv_videos
  

  4- pvdisplay
• Display the Logical volume associated with a given physical volume , among other information:

  pvdisplay -m /dev/sdb1
  

  5- pvs
• list the logical volume (segments) inside a given Physical Volume:

  pvs  /dev/sdb1  --segments  -o +lv_name,lv_size
  

• Complex command, but full list :

  pvs   --segments  -o pv_name,pv_size,seg_size,vg_name,lv_name,lv_size,seg_pe_ranges
  

  vg (volume group)

  At least one physical volume is required to create a volume group.

  create vg

  vgcreate

  vgcreate testvg /dev/sdx1 /dev/sdx2 ...
  

  list VGs or get vg details

  vgdisplay testvg #testvg is optional
  

  lv ( logical volume )

  create lv in existing vg

  lvcreate -n lv_data1 --size 12G testvg
  

• options: -n : volume name --size[-L] : volume lv size -p{r|rw} : permision -M{y|n} : persistent

Display

lvdisplay