If you are using Azure VM --os-disk-size-gb parameter to increase the size of the OS disk, you need to partition, format and mount to use it.
Check the current status with
fdisk -l
df -Th
Step 1: Create a partition (See sample output below)
sudo fdisk /dev/sda
(use n to create new partition, and follow prompts)
Step 2: Refresh partition table
sudo partprobe
Step 3: Format the new partition, get the name from step 1 or use fdisk -l
Step 4: Mount
mkdir /mnt/shared
mount /dev/sda3 /mnt/shared/
Step 5: Verify
df -Th
Step 6: Edit the /etc/fstab to automatically mount when restarted
Append line
/dev/sda3 /mnt/shared xfs defaults 0 0 . Please note the filesystem type "xfs" is used as it was formatted in "xfs" in Step 3. You could use other formats as well based on your requirements .
#
# /etc/fstab
# Created by anaconda on Wed Dec 19 23:06:16 2018
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
UUID=fdb125e2-1ce5-4b7a-98db-88c0f66a86ee / xfs defaults 0 0
UUID=d4c5a046-3513-4ff0-a955-621311869210 /boot xfs defaults 0 0
/dev/sda3 /mnt/shared xfs defaults 0 0
Sample Output:
[root@azvm azureusr]# fdisk /dev/sda
The device presents a logical sector size that is smaller than
the physical sector size. Aligning to a physical sector (or optimal
I/O) size boundary is recommended, or performance may be impacted.
Welcome to fdisk (util-linux 2.23.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): n
Partition type:
p primary (2 primary, 0 extended, 2 free)
e extended
Select (default p):
Using default response p
Partition number (3,4, default 3):
First sector (62914560-125829119, default 62914560):
Using default value 62914560
Last sector, +sectors or +size{K,M,G} (62914560-125829119, default 125829119):
Using default value 125829119
Partition 3 of type Linux and of size 30 GiB is set
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.
[root@azvm azureusr]# partprobe
[root@azvm azureusr]# fdisk -l
Disk /dev/sda: 64.4 GB, 64424509440 bytes, 125829120 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk label type: dos
Disk identifier: 0x000eba6a
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 1026047 512000 83 Linux
/dev/sda2 1026048 62914559 30944256 83 Linux
/dev/sda3 62914560 125829119 31457280 83 Linux
Disk /dev/sdb: 751.6 GB, 751619276800 bytes, 1468006400 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk label type: dos
Disk identifier: 0x3fde6d89
Device Boot Start End Blocks Id System
/dev/sdb1 128 1468004351 734002112 83 Linux
[root@azvm azureusr]# df -Th
Filesystem Type Size Used Avail Use% Mounted on
/dev/sda2 xfs 32G 5.8G 26G 19% /
devtmpfs devtmpfs 186G 0 186G 0% /dev
tmpfs tmpfs 186G 0 186G 0% /dev/shm
tmpfs tmpfs 186G 9.5M 186G 1% /run
tmpfs tmpfs 186G 0 186G 0% /sys/fs/cgroup
/dev/sda1 xfs 521M 68M 454M 13% /boot
/dev/sdb1 ext4 740G 76M 703G 1% /mnt/resource
tmpfs tmpfs 38G 0 38G 0% /run/user/1000
[root@azvm azureusr]# mkfs.xfs /dev/sda3
meta-data=/dev/sda3 isize=512 agcount=4, agsize=1966080 blks
= sectsz=4096 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=7864320, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=3840, version=2
= sectsz=4096 sunit=1 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
[root@azvm azureusr]# mkdir /mnt/shared
[root@azvm azureusr]# mount /dev/sda3 /mnt/shared/
[root@azvm azureusr]# df -Th
Filesystem Type Size Used Avail Use% Mounted on
/dev/sda2 xfs 30G 5.4G 25G 19% /
devtmpfs devtmpfs 174G 0 174G 0% /dev
tmpfs tmpfs 174G 0 174G 0% /dev/shm
tmpfs tmpfs 174G 9.1M 174G 1% /run
tmpfs tmpfs 174G 0 174G 0% /sys/fs/cgroup
/dev/sda1 xfs 497M 65M 433M 13% /boot
/dev/sdb1 ext4 689G 73M 654G 1% /mnt/resource
tmpfs tmpfs 35G 0 35G 0% /run/user/1000
/dev/sda3 xfs 30G 33M 30G 1% /mnt/shared
