Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

i got this error when executing "apt-get update", and only this file failed to download.

Failed to fetch    Hash Sum mismatch
Some index files failed to download, they have been ignored, or old ones used instead.

this error has been repeated for a while. how can i fix this?

i tried both the servers in my country, and the main server in the US. both give the same results. i am not behind any cache server.

share|improve this question
up vote 1 down vote accepted

Usually, you can get rid of those errors by doing:

root@host:~# apt-get clean
root@host:~# cd /var/lib/apt
root@host:/var/lib/apt# mv lists lists.old
root@host:/var/lib/apt# mkdir -p lists/partial
root@host:/var/lib/apt# apt-get update

As I understand it, these errors occur mainly when you're behind a caching proxy.

share|improve this answer
i did as you said, and i got the following when running at-get update W: GPG error: maverick-security Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <> W: Failed to fetch Hash Sum mismatch E: Some index files failed to download, they have been ignored, or old ones used instead. what should i do? – davidshen84 Feb 16 '11 at 0:49
My problem here is that I choose to be behind a caching proxy in order to expedite network installs without needing to run a local package mirror. I'd much rather find a way to avoid these problems but still be able to cache. – Jon Topper Apr 14 '11 at 23:53

It's not their fault, the checksum from matches the md5sum/sha1sum/sha256sum of

Such checksum errors are often caused by a bad network connection. Have you set up some kind of caching server between your server and the Internet?

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.