Upgrading Drush 6 to Drush 9 on Centos 5 server

Question

I haven't updated drush in awhile and looking to update it to the latest. I'm not exactly sure how it was installed originally. But when I do a which drush, it shows it resides in /usr/bin/drush

When I do a drush dl drush - I only get the option to upgrade to 7.x only.

How can I update it to Drush 9?

Can I just do a git clone of the drush repo from: https://github.com/drush-ops/drush

Then do I just do a checkout of the drush 9 tag? But how do I make it the default drush application to run? Or do I just overwrite the file in /usr/bin/drush?

FYI: My linux server admin skills aren't up to par.

Answer 1

drush dl drush downloads the obsolete version of Drush from drupal.org. Drush was never intended to be used to download Drush via the pm-download command, even when it was hosted on drupal.org; the fact that this works is more of an anomaly or coincidence than design.

To update to a newer Drush, follow the usual instructions in the Drush documentation. Since you already have Drush in usr/bin/drush, use this location instead of the location stipulated in the docs (usr/local/bin/drush).

wget http://files.drush.org/drush.phar
chmod +x drush.phar
sudo mv drush.phar /usr/bin/drush

The Drush at files.drush.org/drush.phar is always the most recent stable version of Drush. To download a specific version, visit https://github.com/drush-ops/drush/releases. There is a phar available with every release of Drush from version 8 and later. You can, of course, replace your /usr/bin/drush at any time that you need to upgrade.