Not able to update EC2 Linux instance with command 'sudo yum update'

Question

When I try to update EC2 Amazon Linux instance, I get following error:

Loaded plugins: extras_suggestions, langpacks, priorities, update-motd Could not retrieve mirrorlist http://amazonlinux.ap-south-1.amazonaws.com/2/core /latest/x86_64/mirror.list error was 12: Timeout on http://amazonlinux.ap-south-1.amazonaws.com/2/core/latest/x86_64/ mirror.list: (28, 'Connection timed out after 5000 milliseconds')

One of the configured repositories failed (Unknown), and yum doesn't have enough cached data to continue. At this point the only safe thing yum can do is fail. There are a few ways to work "fix" this:

 1. Contact the upstream for the repository and get them to fix the problem.

 2. Reconfigure the baseurl/etc. for the repository, to point to a working
    upstream. This is most often useful if you are using a newer
    distribution release than is supported by the repository (and the
    packages for the previous distribution release still work).

 3. Run the command with the repository temporarily disabled
        yum --disablerepo=<repoid> ...

 4. Disable the repository permanently, so yum won't use it by default. Yum
    will then just ignore the repository until you permanently enable it
    again or use --enablerepo for temporary usage:

        yum-config-manager --disable <repoid>
    or
        subscription-manager repos --disable=<repoid>

 5. Configure the failing repository to be skipped, if it is unavailable.
    Note that yum will try to contact the repo. when it runs most commands,
    so will have to try and fail each time (and thus. yum will be be much
    slower). If it is a very temporary problem though, this is often a nice
    compromise:

        yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true

Cannot find a valid baseurl for repo: amzn2-core/2/x86_64

Any help would be much appreciated.

Is the EC2 instance in a public subnet (that is connected to an Internet Gateway)? The timeout suggests that it does not have network connectivity to the Internet. — John Rotenstein

Vineet Singh Vineet Singh · Accepted Answer · 2021-02-01T22:52:55

Your instance does not have access to internet. You can resolve this in following ways:

If your instance is running in a public subnet make sure it has a public ip attached. Also check if the route table for the public subnet is associated with this subnet and has a route 0.0.0.0/0 pointing to internet gateway.
If you are running your instance in private make sure you have created the NAT Gateway in a public subnet. Check the route table has a route 0.0.0.0/0 pointing to NAT and the subnet is associated with the private route table.
Check if the security group associated with instance has outbound traffic enabled.

Not able to update EC2 Linux instance with command 'sudo yum update'

2 Answers