AWS EC2 EBS disks operations

 

Increase or replace an EBS disk

1. Make a snapshot / backup copy

2. Stop the service which uses this disk (e.g. sudo service mysql stop)

3. Unmount the disk sudo umount /dev/xvdb

4. Via AWS console, "detach Volume"

5. Either "Modify Volume" adding some more space, or "Create" a new one with required size

6. "Attach" volume back to the AMI via console

7. Edit vi /etc/fstab to allow mount / permanent mount, adding a line like

/dev/nvme1n1  /home/adjesty/mnt auto defaults,noatime,nofail 0 2

7a. For a new volume, create the file system then mount & change the ownership / permissions from 'root'

sudo mkfs.ext4 /dev/xvdg

If there is a need to change the default amount of inodes** (Crawlers case when we create zillions of very small files) then use "-i <bytes-per-node>" flag as per reference

sudo mkfs.ext4 -i 1800 /dev/xvdg

the above will allocate 1800 bytes per an inode, so a 1GB disk will get 596,523 inodes (assuming each file is less than 1,800 bytes)

sudo mount /dev/xvdg
sudo chown -R mysql:mysql /db_tmp

7b. For the increased volume, mount & extend the file system

First, check that the device is in /etc/fstab, e.g.:

/dev/xvdg /db_data auto defaults,noatime,nofail 0 2

Next, mount it & then resize

sudo mount /dev/xvdg
sudo resize2fs /dev/xvdg

check with df -h that you have got the designed size:

Filesystem      Size  Used Avail Use% Mounted on
udev            216M     0  216M   0% /dev
tmpfs            46M  1.9M   44M   5% /run
/dev/nvme0n1p1  9.7G  7.6G  2.1G  79% /
tmpfs           230M     0  230M   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           230M     0  230M   0% /sys/fs/cgroup
/dev/loop2       33M   33M     0 100% /snap/amazon-ssm-agent/2996
/dev/loop3       56M   56M     0 100% /snap/core18/2066
/dev/loop1       34M   34M     0 100% /snap/amazon-ssm-agent/3552
/dev/loop5       99M   99M     0 100% /snap/core/11081
/dev/loop6       56M   56M     0 100% /snap/core18/2074
/dev/loop4      100M  100M     0 100% /snap/core/11316
tmpfs            46M     0   46M   0% /run/user/1001
/dev/nvme1n1    492G   14G  458G   3% /home/adjesty/mnt

AWS instructions are here

For machines that already come with disks:

adjesty@ip-172-31-15-45:~$ lsblk
NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
loop0         7:0    0    89M  1 loop /snap/core/7713
loop1         7:1    0    18M  1 loop /snap/amazon-ssm-agent/1480
loop3         7:3    0    18M  1 loop /snap/amazon-ssm-agent/1455
loop4         7:4    0  89.1M  1 loop /snap/core/8039
nvme0n1     259:0    0 838.2G  0 disk /qt
nvme1n1     259:1    0    10G  0 disk 
└─nvme1n1p1 259:2    0    10G  0 part /

sudo mkfs.ext4 /dev/nvme0n1
sudo mkdir /ext
sudo mount /dev/nvme0n1 /ext