volume

GCP Extend ext4 Boot Volume

July 28, 2022 by Ulysses

Here’s how to extend an ext4 boot volume.

gcloud compute disks resize DISK_NAME --size DISK_SIZE

Resize the file system. Example / is on sda3.

growpart /dev/sda 3
resize2fs /dev/sda3

EBS volume stuck in CloudFormation

November 12, 2020 by Ulysses

When running CloudFormation, all the resources are being created with no problem. However it seems to be getting stuck at creating or mounting a volume. The CloudFormation fails and initiates a rollback. This is the error I am getting.

Volume attachment between volume-id vol-xxxxxxxx and instance-id i-xxxxxxx at device /dev/xvda is attaching

This turned out to be a conflict on HVM EC2 instances because /dev/sda1 is being remapped to /dev/xvda. My second drive is also mapped to /dev/xvda. The fix was to simply to map it slightly different to avoid mapping conflict.

Here’s the original mapping.

Boot:   /dev/xvda
Device: /dev/xvda
Device: /dev/xvdb

Here’s the fix.

Boot:   /dev/xvda
Device: /dev/xvdb
Device: /dev/xvdc

GCP Identify Your Disks

September 16, 2020 by Ulysses

Here’s how to identify your disks on the system to cross check with GCP Dashboard.

ls -l /dev/disk/by-id

Result:

[root@servername ~]# ls -l /dev/disk/by-id
total 0
lrwxrwxrwx. 1 root root  9 Sep 15 05:30 google-boot -> ../../sda
lrwxrwxrwx. 1 root root 10 Sep 15 05:30 google-boot-part1 -> ../../sda1
lrwxrwxrwx. 1 root root  9 Sep 15 05:30 google-persistent-disk-1 -> ../../sdb
lrwxrwxrwx. 1 root root  9 Sep 15 05:30 scsi-0Google_PersistentDisk_boot -> ../../sda
lrwxrwxrwx. 1 root root 10 Sep 15 05:30 scsi-0Google_PersistentDisk_boot-part1 -> ../../sda1
lrwxrwxrwx. 1 root root  9 Sep 15 05:30 scsi-0Google_PersistentDisk_persistent-disk-1 -> ../../sdb

Encrypt Volume via Terraform

April 9, 2019 by Ulysses

Here’s the Terraform script to encrypt an unencrypted volume. It creates a snapshot, encrypts a snapshot, and encrypts the volume.

#
# Set Variables
#
variable "volume" {
  description = "The Volume to encrypt: vol-12345678901234567"
}
variable "region" {
  description = "The Region: us-east-2"
}
variable "az" {
  description = "The AZ: us-east-2a"
}
 
#
# Set Credentials
#
provider "aws" {
	access_key = "put-your-access-key-here"
	secret_key = "put-your-secret-key-here"
	region = "${var.region}"
}
 
/*
#
# Create Unencrypted Volume
#
resource "aws_ebs_volume" "unencrypted_volume" {
  availability_zone = "${var.az}"
  size              = 10
  tags = {
    Name = "Unencrypted_Volume"
  }
}
*/
 
#
# Create Unencrypted Snapshot
#
resource "aws_ebs_snapshot" "unencrypted_snapshot" {
  #volume_id = "${aws_ebs_volume.unencrypted_volume.id}"
  volume_id = "${var.volume}"
  tags = {
    Name = "Unencrypted_Snapshot"
  }
}
 
#
# Create Encrypted Snapshot
#
resource "aws_ebs_snapshot_copy" "encrypted_snapshot" {
  source_snapshot_id = "${aws_ebs_snapshot.unencrypted_snapshot.id}"
  source_region      = "${var.region}"
  encrypted = true
  tags = {
    Name = "Encrypted_Snapshot"
  }
}
 
#
# Created Encrypted Volume
#
resource "aws_ebs_volume" "encrypted_volume" {
  availability_zone = "${var.az}"
  snapshot_id = "${aws_ebs_snapshot_copy.encrypted_snapshot.id}"
  tags = {
    Name = "Encrypted_Volume"
  }
}

LVM Extend Physical Volume

March 14, 2019 by Ulysses

The following are instructions on how to extend a disk volume with LVM.

# aws cli extend volume
aws ec2 modify-volume --region us-east-1 \
--volume-id vol-xxxxxxxxxxxx --size 15 \
--volume-type gp2
# check volumes before
lsblk
# extend via growpart
growpart /dev/xvdf 1
# check volumes after
lsblk
# resize physical volume
pvresize /dev/xvdf1
# check physical volume
pvscan
# extend logical volume
lvresize -l +100%FREE /dev/data/data
# check logical volume
lvscan
# check mounts
df -Th
# resize file system
resize2fs /dev/data/data
# or
xfs_growfs /dev/mapper/root
xfs_growfs /dev/xvda1
# check mounts again for new size
df -Th

Extend LVM volume

January 28, 2019 by Ulysses

Extending a LVM logical volume can be tricky. Extending a physical volume especially a boot drive is even more challenging. To make things simple, you can just easily add a new physical disk to your physical volume group. Here are the steps:

# add disk to your instance. 
fdisk /dev/sdh
pvcreate /dev/sdh1
vgextend system /dev/sdh1
lvextend -l +100%FREE /dev/system/opt
resize2fs /dev/system/opt

The fdisk command requires a few steps inside such as creating a new partition, changing the partition to type to “8e” which is Linux LVM, and then writing your changes to disk.

The rest are pretty much self explanatory. It’s about creating a physical volume, extending the volume group, extending the logical volume, and then finally resizing the file system.

Extend an EBS Volume

March 5, 2018 by Ulysses

As a Cloud Engineer, I get a few requests to extend an EBS volume. For example, the application owner wants to double the size of the /data volume from 10GB to 20GB. The nice part about extending an EBS volume is that it can all be done on the fly without bringing down the instance. Adding more storage can be done via the AWS Console. Check out this article from AWS about modifying an EBS volume. But that’s just the first part. Although you’ve doubled the disk space, you still have to let the system know it now has doubled it’s disk space. The second part is to grow or resize the file system. Here’s the other article on how to extend a file system.

# expand
growpart /dev/xvdb
# for ext2, ext3 and ext4
resize2fs /dev/xvdb
# for xfs
xfs_growfs -d /dev/xvdb