Remote Ec2 Gpu2

Remote EC2 gpu2

Overview

This machine is the control node. The peer EC2 server should be accessed through the local SSH alias gpu2, not by retyping raw connection details unless debugging the SSH config itself.

Current remote target:

• SSH alias: gpu2
• Remote host: 172.31.33.255
• Remote user: ubuntu
• SSH key on this machine: ~/.ssh/XudongChen.pem
• SSH config file: ~/.ssh/config

When To Use

Use this skill when the user asks to:

• connect to the peer EC2 server
• run code, training, evaluation, or shell commands on the peer EC2 server
• verify whether the peer EC2 server is reachable after reboot
• inspect logs, processes, GPUs, or tmux sessions on the peer EC2 server
• copy files between this machine and the peer EC2 server

Standard Workflow

1. Confirm the SSH alias exists before assuming connectivity:

ssh -G gpu2 | sed -n '1,40p'

2. For a quick connectivity check, prefer a short non-interactive command:

ssh -o BatchMode=yes -o ConnectTimeout=5 gpu2 'hostname && whoami && pwd'

3. For one-off remote execution, run through the alias:

ssh gpu2 'cd ~/repo && python your_script.py'

4. For long-running jobs, use tmux on the remote host:

ssh gpu2 'tmux new -d -s job "cd ~/repo && python train.py > train.log 2>&1"'
ssh gpu2 'tmux ls'
ssh gpu2 'tail -n 100 ~/repo/train.log'

5. For interactive work, open a shell session:

ssh gpu2

File Transfer

Copy from this machine to the remote host:

scp /path/to/local.file gpu2:/path/to/remote.file

Copy from the remote host to this machine:

scp gpu2:/path/to/remote.file /path/to/local.file

For directories:

scp -r /path/to/local_dir gpu2:/path/to/remote_dir
scp -r gpu2:/path/to/remote_dir /path/to/local_dir

Safety And Operating Rules

• Prefer the alias gpu2 over raw IPs so future host changes stay localized to ~/.ssh/config.
• Do not overwrite or move ~/.ssh/XudongChen.pem unless the user explicitly asks.
• Treat remote commands as high-impact. Avoid destructive operations unless the user explicitly requested them.
• Before launching expensive jobs, verify the target path, environment, and available GPU or disk state on the remote host.
• When checking connectivity from Codex, real SSH probes may require escalated execution because the local sandbox can block outbound sockets.

Useful Remote Checks

ssh gpu2 'hostname -I'
ssh gpu2 'nvidia-smi'
ssh gpu2 'df -h'
ssh gpu2 'free -h'
ssh gpu2 'ps -ef | grep python'
ssh gpu2 'tmux ls'

Notes

• The peer EC2 server has already been verified as reachable from this machine over private IP.
• After a normal reboot, the peer server remained reachable at 172.31.33.255 during prior testing.