cloud engineer
If you don’t have it installed.
yum install screen apt install screen |
Before you run a process, run screen, and detach.
screen # run the command ping yahoo.com # ctrl-a and ctrl-d to detach |
To reattach, get a list of screen sessions, and attach to it.
screen -ls # result is somewhat similar to below 4452.hostname # attach to it screen -dr 4452.hostname |
To stop, just type exit from the screen terminal.
Here’s a quick way to chroot another boot disk. Attach the rescued boot disk first. Run lsblk and mount.
lsblk mount -t xfs -o nouuid /dev/xvdf2 /mnt mount --bind /proc /mnt/proc mount --bind /sys /mnt/sys mount --bind /dev /mnt/dev chroot /mnt cd /mnt exit |
Unmount when done.
umount /mnt/proc umount /mnt/dev umount /mnt/sys umount /mnt |
Get instance details
aws lightsail get-instance --instance-name your-server |
Get instance state
aws lightsail get-instance-state --instance-name your-server |
Create a snapshot
aws lightsail create-instance-snapshot \ --instance-snapshot-name your-server-new-snapshot-201905192200 \ --instance-name your-server |
Create disk from snapshot
aws lightsail create-disk-from-snapshot \ --disk-name your-server-new-boot-disk \ --disk-name your-server-new-snapshot-201905192200 \ --availability-zone us-east-1a --size-in-gb 50 |
Attach Disk
aws lightsail attach-disk \ --disk-name your-server-new-boot-disk \ --instance-name your-server \ --disk-path /dev/sda1 |
Create instance from snapshot
aws lightsail create-instance-snapshot \ --instance-snaphot-name your-server-new-snapshot-201905192200 --instance-name your-server |
Attach Static IP Address
aws lightsail attach-static-ip \ --static-ip-name your-ip-name \ --instance-name your-server |
Google Cloud Platform just recently released a beta feature called detaching and attaching boot disks. Previously, boot disks were permanently attached to their VM instances. Now you have the ability to detach boot disk from your instance and attach it to another instance without deleting the original instance. You can also replace the boot disks for an instance rather than recreating the entire instance. I’ve tested it on my test account, and it works quite nicely.
I have 2 servers called blue-server and red-server. I’m detaching the disks on blue-server and attaching it to the red-server.
gcloud compute instances detach-disk blue-server --disk=blue-server-disk --zone us-central1-c gcloud compute instances attach-disk cyan-server --disk=blue-server-disk --zone us-central1-c gcloud compute instances detach-disk cyan-server --disk=blue-server-disk --zone us-central1-c gcloud compute instances attach-disk blue-server --disk=blue-server-disk --zone us-central1-c |
Results:
This new GCP feature is still beta. There might be a few quirks here and there, but overall, it’s a must have feature if you are managing OS.
Attaching an EBS volume to an existing instance is quite easy. You can easily add them via the AWS Console. With just a few clicks, you can add an EBS volume in no time. Just click the Create Volume button, indicate the size of the volume, choose which availability zone (preferably the same AZ where your instance resides), and enable encryption if you decide to do so. You can also add an EBS volume from an existing snapshot.
There are 2 steps to attaching an EBS volume to an existing instance.
Step 1. Attach an EBS volume.
How to attach an EBS to an existing Instance.
Step 2. Make the EBS volume available to your instance whether it’s Linux or Windows. This requires SSH access.
Making an EBS volume available to Linux.
Making an EBS volume available to Windows.