Detailed explanation of CentOS lsblk commands

"Lsblk is used to list Block devices. In addition to RAM, Block devices are displayed neatly in the standard tree output format.

01root@tecmint:~# lsblk02
03NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT04sda 8:0 0 232.9G 0 disk05├─sda1 8:1 0 46.6G 0 part /06├─sda2 8:2 0 1K 0 part07├─sda5 8:5 0 190M 0 part /boot08├─sda6 8:6 0 3.7G 0 part [SWAP]09├─sda7 8:7 0 93.1G 0 part /data10└─sda8 8:8 0 89.2G 0 part /personal11sr0 11:0 1 1024M 0 rom

"The lsblk-l command displays Block devices in the List format (instead of the tree format ).

01root@tecmint:~# lsblk -l02
03NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT04sda 8:0 0 232.9G 0 disk05sda1 8:1 0 46.6G 0 part /06sda2 8:2 0 1K 0 part07sda5 8:5 0 190M 0 part /boot08sda6 8:6 0 3.7G 0 part [SWAP]09sda7 8:7 0 93.1G 0 part /data10sda8 8:8 0 89.2G 0 part /personal11sr0 11:0 1 1024M 0 rom

Note:Lsblk is the most useful and easiest way to understand the names of newly inserted USB devices, especially when you process disks/Block devices on a terminal.

Lsblk command to View Block devices and file system information[Root @ kashu ~] # LsblkNAME MAJ: min rm size ro type MOUNTPOINTsr0 1 1024 M 0 rom sda 0 20G 0 disk restart-sda1 80 500 M 0 part/boot restart-sda2 0 19.5G 0 part restart -VolGroup-lv_root (dm-0) 253: 0 0 18.5G 0 lvm/VolGroup-lv_swap (dm-1) 253: 1 0 1G 0 lvm [SWAP] sdb 8: 16 0 20G 0 disk running-sdb1 8: 17 0 1G 0 part loading-sdb2 8: 18 0 1G 0 part loading-sdb3 8: 19 0 1G 0 part │ mongo── md126 126 0 2G 0 raid5 │ mongo── md126p1 259: 0 0 1G 0 md ─ ── sdb4 8:20 0 1 K 0 part ├ ── sdb5 8:21 0 1G 0 part │ ─ ── md126 9:126 0 2G 0 raid5 │ ─ ── md126p1 259: 0 0 1G 0 md ├ ── sdb6 8:22 0 1G 0 part │ ─ ── md125 9:125 0 2G 0 raid5 then ── sdb7 8:23 0 1G 0 part │ ─ ── md125 9:125 0 2G 0 raid5 random-sdb8 0 1G 0 part │ random-md125 125 0 2G 0 raid5 random-sdb9 0 1G 0 part │ random-md127 127 0 2G 0 raid5 upload-sdb10 0 1G 0 part upload-md127 127 0 2G 0 raid5The output contains information about the file system.[Root @ kashu ~] # Lsblk-f

Name fstype label MOUNTPOINTsr0 sda %── sda1 ext4/boot %── sda2 LVM2_member %─ VolGroup-lv_root (dm-0) ext4/%─ VolGroup-lv_swap (dm-1) swap [SWAP] sdb %─ sdb1 %kashu. localdomain: 0 ├ ── sdb2 linux_raid_member kashu. localdomain: 0 ├ ── sdb3 linux_raid_member kashu. localdomain: 0 │ ‑md126 ext4 │ ‑md126p1 ext4 ‑sdb4 ‑sdb5 linux_raid_member kashu. localdomain: 0 │ ‑md126 ext4 │ ‑md126p1 ext4 ‑sdb6 linux_raid_member kashu. localdomain: d0 │ mongo-md125 ├ ── sdb7 linux_raid_member kashu. localdomain: d0 │ mongo-md125 ├ ── sdb8 linux_raid_member kashu. localdomain: d0 │ mongo-md125 ├ ── sdb9 linux_raid_member kashu. localdomain: 0 │ ─ ── md127 ext4 %─ sdb10 linux_raid_member kashu. localdomain: 0 bytes-md127 ext4Output in list form[Root @ kashu ~] # Lsblk-l

Name maj: min rm size ro type MOUNTPOINTsr0 1 1024 M 0 rom sda 0 20G 0 disk sda1 80 500 M 0 part/bootsda2 0 19.5G 0 part VolGroup-lv_root (dm-0) 253: 0 0 18.5G 0 lvm/VolGroup-lv_swap (dm-1) 253: 1 0 1G 0 lvm [SWAP] sdb 0 20G 0 disk sdb1 0 1G 0 part sdb2 0 1G 0 part sdb3 19 0 1G 0 part md126 126 0 2G 0 raid5 md126p1 259: 0 0 1G 0 md sdb4 0 1 K 0 part sdb5 0 1G 0 0 part md126 126 0 2G 0 raid5 md126p1 259: 0 0 1G 0 md sdb6 0 1G 0 part md125 125 0 2G 0 raid5 sdb7 0 1G 0 part md125 0 2G 0 raid5 sdb8 0 1G 0 part md125 125 0 2G 0 raid5 sdb9 0 1G 0 part md127 127 0 2G 0 raid5 sdb10 26 0 1G 0 part md127 127 0 2G 0 raid5Display as Topology[Root @ kashu ~] # Lsblk-t

Name alignment MIN-IO OPT-IO PHY-SEC LOG-SEC rota sched RQ-SIZEsr0 0 512 0 512 512 1 cfq 128sda 0 512 0 512 512 1 cfq 128 running-sda1 0 512 0 512 1 cfq 512 running-sda2 0 512 0 512 512 1 cfq 128 108── VolGroup-lv_root (dm-0) 0 512 0 512 512 1 128 running-VolGroup-lv_swap (dm-1) 0 512 0 512 512 1 128sdb 0 512 512 512 1 cfq 128 running-sdb1 0 512 0 512 512 1 cfq 128 running-sdb2 0 512 0 512 512 1 cfq 128 running-sdb3 0 512 0 512 512 1 cfq 128 │ └ ── md126 0 524288 1048576 512 512 1 128 │ ─ ── md126p1 0 524288 1048576 512 512 1 128 108── sdb4 0 512 0 512 512 1 cfq 128 running-sdb5 0 512 0 512 512 1 cfq 128 │ running-md126 0 524288 1048576 512 512 1 128 │ running-md126p1 0 524288 1048576 512 1 512 running-sdb6 0 128 0 512 512 1 cfq 128 │ └ ── md125 0 524288 1048576 512 512 1 128 108── sdb7 0 512 0 512 512 1 cfq 128 │ └ ── md125 0 524288 1048576 512 512 1 128 ├ ── sdb8 0 512 0 512 512 1 cfq 128 │ └ ── md125 0 524288 1048576 512 512 1 128 108── sdb9 0 512 0 512 512 1 cfq 128 │ └ ── md127 0 524288 1048576 512 512 1 128 running-sdb10 0 512 0 512 512 1 cfq 128 running-md127 0 524288 1048576 512 512 1 128