Getting Started with the Linux Repository Service

Follow the information below to get started with the service.

Steps to Configure a Repository Mirror

For Ubuntu

1. Backup and Edit Sources List:

   ```bash
   sudo cp /etc/apt/sources.list /etc/apt/sources.list.backup
   sudo nano /etc/apt/sources.list
   ```

   Replace current URLs with those from a closer mirror.

   List of Ubuntu mirrors

   (ex. https://mirror.its.umich.edu/ubuntu/)

2. Update Package Lists:

   ```bash
   sudo apt update
   ```

For EPEL (Enterprise Linux)

1. Install EPEL Repository:

   
       ```bash
       sudo yum install epel-release
       ```

2. Edit EPEL Repo File:

   ```bash
       sudo nano /etc/yum.repos.d/epel.repo
       ```
   

   Replace `baseurl` with mirror.its.umich.edu

   List of EPEL mirrors

3. Clean and Update Cache:

   ```bash
       sudo yum clean all
       sudo yum makecache
       ```

For CRAN (R Language)

1. Configure R to Use a Mirror:

   Edit `.Rprofile` for global settings:

   ```r
       options(repos = c(CRAN = "https://mirror.its.umich.edu/cran/"))
       ```

   For session-only changes:

   ```r
       chooseCRANmirror(graphics=FALSE, ind=<mirror_index>)
       options(repos = c(CRAN = "https://mirror.its.umich.edu/cran/"))
       ```

   List of CRAN mirrors

2. Test the Configuration:

   ```r
       install.packages("ggplot2")
       ```