accounts.md

+# Accounts
+
+The servers use a unified accounts system. Accounts are created by sysadmins only. If you are reading this, you probably already have a username and a password.
+
+## Passwords
+
+You can change your password by logging in to `philae.polito.it` (see the [connection](pages/common/connection) guide) and using the `passwd` command. You cannot change your password from other servers. Remember to always use a secure password.
+
+## Expiration
+
+Accounts have an expiration date that depends on the owner's role in the group. Expiration dates are computed as follows:
+
+| Role | Expiration |
+| ------ | ------ |
+| Thesis Student | 6 months after account creation |
+| Research Assistant/Post Doc. | 1 year after account creation |
+| PhD Student | 3 years after account creation | 
+| Professor/RTD | unlimited |  
+ 
+One month prior to the expiration date, you receive a reminder e-mail at the address associated with your account. If you need an extension (for example, because you renewed your contract), you should ask your supervisor to contact the system administrators *at least 5 days before* the expiration date.
+
+**IMPORTANT: after an account expires, access to the server will be disabled and data stored on all servers will be deleted.** Each supervisor has the responsibility to arrange all needed data exchanges with people leaving the group *before* their accounts expire. System administrators cannot be blamed for lost data!