Questions tagged [amazon-ec2]
Amazon Elastic Compute Cloud (EC2) provides self-service, on-demand, pay-for-what-you-use computing infrastructure resources.
6,604
questions
228
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Permission denied (publickey). SSH from local Ubuntu to Amazon EC2 server
I have an instance of an application running in the cloud on an Amazon EC2 instance, and I need to connect to it from my local Ubuntu. It works fine on one local ubuntu and also laptop. I got this ...
158
votes
3
answers
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Delete Amazon EC2 terminated instance
I created an Amazon Free tier Usage Account. I launched two amazon ec2 instances using the online tool. After that one instance was created and running while other was pending which quickly shifted to ...
146
votes
3
answers
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How can I upgrade to Java 1.8 on an Amazon Linux Server?
I tried sudo yum update but it just keeps java "1.7.0_75". I need 1.8 for it to work with another application but can't figure out how to upgrade it.
Do I need to manually install it somehow? There's ...
128
votes
4
answers
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Amazon EC2 terminology - AMI vs. EBS vs. Snapshot vs. Volume
I have been poking around Amazon EC2, and am a little confused on some of the terminology. Specifically with regard to AMI, snapshots and volumes, and an EBS
Please correct me if I am wrong, or fill ...
126
votes
7
answers
167k
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What Linux distribution is the Amazon Linux AMI based on?
Amazon Web Services (AWS) offers an officially supported Amazon Machine Image (AMI), but it doesn't indicate which Linux distribution it's based upon.
Is the official Amazon Linux AMI based on ...
124
votes
7
answers
103k
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How to change an EC2 instance's security group
I have created a new EC2 instance. It got assigned the default security group. I want to change that security group. How?
111
votes
8
answers
31k
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Why does my OpenSSH key fingerprint not match the AWS EC2 console keypair fingerprint?
When I import my OpenSSH public key into AWS EC2's keyring the fingerprint that AWS shows doesn't match what I see from:
ssh-keygen -l -f my_key
It is a different length and has different bytes.
...
103
votes
9
answers
109k
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How to add a security group to a running EC2 Instance?
I have an Amazon EC2 instance running and I will like to add another security group to that instance and then remove the current security group from that instance. Is this possible?
101
votes
6
answers
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How to get a .pem file from ssh key pair?
I created a key pair using ssh-keygen and get the two clasic id_rsa and id_rsa.pub.
I imported the public key into my AWS EC2 account.
Now I created a windows instance and to decrypt that instance ...
96
votes
6
answers
174k
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Assign Public IP (not Elastic IP) after instance launched
When I launch instance in AWS console I can set "Auto-assign Public IP" to true and newly created instance will be assigned with public IP address from pool.
Now assume I have launched instance with ...
93
votes
5
answers
51k
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Why don't EC2 ubuntu images have swap?
I started a couple servers on EC2 and they don't have swap.
Am I doing something wrong or is it that the machines just don't have any?
91
votes
4
answers
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How to change the name and description of an AWS EC2 security group?
How do you change the name and description of a security group in AWS EC2?
My security group is named quick-start-1 (the default) and I want to change it to "HTTP, HTTPS and Limited SSH".
89
votes
4
answers
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Why is TCP accept() performance so bad under Xen?
The rate at which my server can accept() new incoming TCP connections is really bad under Xen. The same test on bare metal hardware shows 3-5x speed ups.
How come this is so bad under Xen?
Can you ...
86
votes
7
answers
101k
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Amazon Linux vs. Ubuntu for Amazon EC2 [closed]
I'm setting up my first website on Amazon EC2, and I'm trying to decide which distro to use. I've used Redhat and CentOS in the past, but I have no bias towards any system, I just want to use whatever ...
77
votes
4
answers
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What is the difference between PV and HVM virtualization types in ec2?
AWS EC2 offers two types of virtualization of Ubuntu Linux EC2 machines - PV and HVM.
PV:
HVM:
What is the difference between these types?
74
votes
9
answers
115k
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Cannot SSH: debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY [closed]
We have a server on Amazon EC2 running SSH is on a standard (22) port.
I placed my public key at the <username>/.ssh/authorized_keys file.
The fun thing is that yesterday it was working great! ...
73
votes
10
answers
189k
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xvda1 is 100% full, What is it? how to fix?
I'm running a Linux instance on EC2 (I have MongoDB and node.js installed) and I'm getting this error:
Cannot write: No space left on device
I think I've tracked it down to this file, here is the df ...
71
votes
3
answers
70k
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Search ec2 instance by its name from aws command line tool
I have an instance named dev-server-03. Now how can I search all dev-server-* instances from command line?
I am using aws cli tool.
71
votes
4
answers
69k
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What is the "slash" after the IP? [duplicate]
In Amazon EC2, where I set "security groups", It says: Source:
0.0.0.0/0
And then it gives an example of: 192.168.2.0/24
What is "/24"?
I know what port and IP is.
63
votes
4
answers
92k
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Download SSL certificate from aws certificate manager
I am using aws certificate manager for managing SSL. Recently I purchased a wildcard ssl *.example-private.com Now I need that SSL certificate to deploy on enterprise git instance on aws.
How can i ...
62
votes
5
answers
39k
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How can I check /dev/xvda1?
On login to EC2 (Ubuntu) instance, I see
*** /dev/xvda1 should be checked for errors ***
I can't fsck /dev/xvda1 because it is mounted, and sudo umount /dev/xvda1 fails because it is in use. lsof ...
62
votes
14
answers
47k
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How to know if a machine is an EC2 instance
I would like to run some scripts on hosts which are EC2 instances but I don't know how to be sure that the host is really an EC2 instance.
I have made some tests, but this is not sufficient:
Test ...
61
votes
4
answers
46k
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Multiple EC2 security groups - permissive or restrictive?
What happens when I assign multiple security groups to an instance? Is it permissive in the sense that the traffic is allowed in if any one of the security groups allows it. OR is it restrictive in ...
60
votes
10
answers
56k
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How to determine AWS security group dependencies?
Amazon EC2 won't let me delete a security group, complaining that the group still has dependencies. How Can I find what those dependencies are?
aws ec2 describe-security-groups doesn't say.
58
votes
5
answers
75k
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How to delete Instances in Amazon EC2 ? Change Pair Key?
How to remove Instances ? I test some Instances and now I terminate it. So, I want to remove it. I can't find delete or remove action. I just found terminate.
How to change the pair key ? I don't ...
58
votes
2
answers
57k
views
Are EC2 security group changes effective immediately for running instances?
I have an EC2 instance running, and it belongs to a security group. If I add a new allowed connection to that security group through AWS Management Console, should that change be effective immediately?...
57
votes
7
answers
67k
views
How to delete EC2 AMI
I know that the command ec2-create-image instance-id will be creating an image of the ec2 instance, creating snapshots file and registering as an AMI. But what is the equivalent command to delete the ...
53
votes
4
answers
72k
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What is "freeable memory"?
Amazon RDS has a metric for 'freeable memory'. It appears to go up & down in a sawtooth pattern.
This leads me to believe that it's memory that is being used by MySQL for caching and that when ...
51
votes
5
answers
132k
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How to install Docker on AWS EC2 instance with AMI (CE/EE Update)
What is the current way of installing Docker on an AWS EC2 instance running the AMI?
There has been an announcement of Docker Enterprise Edition and now I want to know if anything has changed.
Until ...
50
votes
5
answers
49k
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Can't connect to EC2 instance in VPC (Amazon AWS)
I've taken the following steps:
Created a VPC (with a single public subnet)
Added an EC2 instance to the VPC
Allocated an elastic IP
Associated the elastic IP with the instance
Created a security ...