Learn Italian: Il database è sul vecchio server. - The database is on the old server.

You would replace the entire phrase sul vecchio server with the clitic ci. Because the verb is è (is), ci drops its vowel and becomes c'è. So, 'The database is on it' becomes Il database c'è. This looks exactly like the phrase for 'there is,' which makes sense since ci can replace phrases starting with su to mean 'on it' as well as 'there'.

Why are the English loanwords database and server masculine?

In Italian, foreign words adopted into the language are almost always treated as masculine by default. That is why they use il and sul. Also, remember that foreign loanwords don't change their endings in the plural, so 'the old servers' would be i vecchi server.

Why is vecchio placed before server instead of after?

Placing vecchio before the noun is very common and gives it a descriptive, familiar feel—often meaning the 'former' or 'previous' server rather than just one that is physically aged. If you put it after the noun (sul server vecchio), it creates a stronger contrast, emphasizing its physical old age compared to a new one.

A quick refresher: why is it sul rather than su il?