I need help with installation of php-devel (I need it, cause it has phpize, which is necessary to install eAccelerator). But when I try to install php-devel with yum i
About the initial question (install eAccelerator).
This project is dead, and have never work with PHP >= 5.4.
So if you need an opcode cache, please choose a maintained one. I would recommend "opcache", the official cache maintained by the PHP project, included in php-src since 5.5, and available in pecl for 5.4.
And if you use "remi" repository, before trying to build an extension, check first if it is available in the repository, as most of the PECL extensions are available as RPM, see http://blog.remirepo.net/pages/PECL-extensions-RPM-status