Add new hard drive in CentOS/RHEL/OEL without reboot

Add new hard drive in CentOS/RHEL/OEL without reboot:

1. First add an new 200 GB hard drive in scsi mode from VMware ESXi console.

Please notice only scsi disk allow operation while power on.

2. Then echo "- - -" > /sys/class/scsi_host/host2/scan

Please notice host2 is the scsi number I added from the ESXi.

# ls /sys/class/scsi_host/
host0/ host1/ host2/

2.1 Before:

# fdisk -l

Disk /dev/sda: 17.2 GB, 17179869184 bytes
255 heads, 63 sectors/track, 2088 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00073bb3

Device Boot Start End Blocks Id System
/dev/sda1 * 1 17 131072 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 17 531 4128768 82 Linux swap / Solaris
Partition 2 does not end on cylinder boundary.
/dev/sda3 531 2089 12516352 83 Linux

Disk /dev/sdb: 107.4 GB, 107374182400 bytes
255 heads, 63 sectors/track, 13054 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xbf77fef7

Device Boot Start End Blocks Id System
/dev/sdb1 1 13054 104856223+ 83 Linux

2.2 Then run:

# echo "- - -" > /sys/class/scsi_host/host2/scan

2.3 After:

# fdisk -l

Disk /dev/sda: 17.2 GB, 17179869184 bytes
255 heads, 63 sectors/track, 2088 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00073bb3

Device Boot Start End Blocks Id System
/dev/sda1 * 1 17 131072 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 17 531 4128768 82 Linux swap / Solaris
Partition 2 does not end on cylinder boundary.
/dev/sda3 531 2089 12516352 83 Linux

Disk /dev/sdb: 107.4 GB, 107374182400 bytes
255 heads, 63 sectors/track, 13054 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xbf77fef7

Device Boot Start End Blocks Id System
/dev/sdb1 1 13054 104856223+ 83 Linux

Disk /dev/sdc: 214.7 GB, 214748364800 bytes
255 heads, 63 sectors/track, 26108 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

2.4 Check if the device showed up:
# ls /dev/sd*
sda sda1 sda2 sda3 sdb sdb1 sdc

3. Format the disk:

3.1 # fdisk /dev/sdc
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0x14910557.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content won't be recoverable.

Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)

WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').

Command (m for help): p

Disk /dev/sdc: 214.7 GB, 214748364800 bytes
255 heads, 63 sectors/track, 26108 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x14910557

Device Boot Start End Blocks Id System

Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-26108, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-26108, default 26108):
Using default value 26108

Command (m for help): p

Disk /dev/sdc: 214.7 GB, 214748364800 bytes
255 heads, 63 sectors/track, 26108 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x14910557

Device Boot Start End Blocks Id System
/dev/sdc1 1 26108 209712478+ 83 Linux

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

3.2 Format into ext4:

# mkfs.ext4 /dev/sdc1
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
13107200 inodes, 52428119 blocks
2621405 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
1600 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424, 20480000, 23887872

Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 31 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.

4. Try to mount the new partition:

# mkdir -p /data2
# mount /dev/sdc1 /data2

vi /etc/fstab
#Data FS - EXT4
/dev/sdb1 /data ext4 defaults 1 2
/dev/sdc1 /data2 ext4 defaults 1 2

5. Test if it works:
# touch lamber_test.please_delete