Hello. Previously debian, ubuntu, opensuse, I've used. But I'm new to CentOS too. I do not install desktop environment. Servers want to learn. I can not update the system. I could not so I researched. I give the following command . "yum update". I get the error. I'm working on a virtual machine. (I do not know English. Translation I wrote using.) One of the configured repositories failed (hand), and yum does not have enough cached data to continue. At this point the only yum can do is fail safe thing. There are a few ways to work "fix" this: 1 Contact the repository for the upstream 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 the Useful if you are using a new release distribution than is supported by the repository (and the for the previous release distribution packages still work). 3 Disable the repository, so yum will not use it by default. When will the Yuma just ignore the repository until you enable it again or use permanently --enablerepo for temporary usage: yum-config-manager --disable hand 4 Configure the repository failing to be skipped, if it is unavailable . Note that yum will try to contact the repo. most commands when it runs, so will have to try and fail each time (and plenty of sunshine. Yum Will be much slower). If it is a very temporary problem, though, this is often a nice compromise: yum-config-manager of --sav --setopt = el.skip_if_unavailabl = true Connot find a valid baseurl for repo: base / 7x86_64 "vi" with CentOS-Base.repo, CentOS-Debuginfo.repo, CentOS-Vault.repo, CentOS -Sources.repo files "enabled = 1" line as I did. But "soft repolist all" command when I type "status = 0" is displayed.