I have server with Ubuntu 16.04 LTS, with php 7.0. Command and output below: Code: [email protected]:/opt/php-5.6.30/etc# ps aux | grep memcached memcache 1256 0.0 0.4 352036 29760 ? Ssl Nov09 1:07 /usr/bin/memcached -m 64 -p 11211 -u memcache -l 127.0.0.1 root 24935 0.0 0.0 12888 1008 pts/2 S+ 08:11 0:00 grep --color=auto memcached It looks like I have memcached but when I try turn on it under Presta admin panel I have error after clicked "Test server". I can only add memcache with ip and port shown above. I attached screens. I tried install memcached for additional php version 5.6.30 installed based on these two (working perfectly): Code: https://www.howtoforge.com/tutorial/how-to-install-php-5-6-on-ubuntu-16-04/#-enable-php-in-ispconfig https://www.howtoforge.com/how-to-use-multiple-php-versions-php-fpm-and-fastcgi-with-ispconfig-3-ubuntu-12.10 but when I execute: Code: [email protected]:/opt/php-5.6.30/etc# pecl -C ./pear.conf install memcached I have to put something in line at the bottom - "libmemcached directory [no] :": Code: [email protected]:/opt/php-5.6.30/etc# pecl -C ./pear.conf install memcached pecl/memcached can optionally use PHP extension "igbinary" (version >= 2.0) pecl/memcached can optionally use PHP extension "msgpack" (version >= 2.0) downloading memcached-3.0.4.tgz ... Starting to download memcached-3.0.4.tgz (78,776 bytes) ..................done: 78,776 bytes 15 source files, building running: phpize Configuring for: PHP Api Version: 20131106 Zend Module Api No: 20131226 Zend Extension Api No: 220131226 libmemcached directory [no] : But I dont know what, and of course after clicked enter button I got an error: Code: checking for libmemcached location... configure: error: memcached support requires libmemcached. Use --with-libmemcached-dir=<DIR> to specify the prefix where libmemcached headers and library are located ERROR: `/tmp/pear/temp/memcached/configure --with-php-config=/opt/php-5.6.30/bin/php-config --with-libmemcached-dir=no' failed How to resolve it?