akonadiserver: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/akonadiserver - from package: akonadi

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/akonadiserver - from package: akonadi-server

You may install the required package with command apt-get install {package}

Error in other languages:
akonadiserver: bevel nie gevind nie
akonadiserver: comandă negăsită
akonadiserver: comando não encontrado
akonadiserver: commande introuvable
akonadiserver: command not found
akonadiserver: käsku ei ole
akonadiserver: không tìm thấy lệnh
akonadiserver: komanda nerasta
akonadiserver: Kommando nicht gefunden.
akonadiserver: kommandot finns inte
akonadiserver: komut yok
akonadiserver: nie znaleziono polecenia
akonadiserver: níor aimsíodh an t-ordú
akonadiserver: no se encontró la orden
akonadiserver: no s'ha trobat l'ordre
akonadiserver: opdracht niet gevonden
akonadiserver: parancs nem található
akonadiserver: perintah tidak ditemukan
akonadiserver: príkaz nenájdený
akonadiserver: příkaz nenalezen
akonadiserver: команда не найдена
akonadiserver: командата не е открита
akonadiserver: 命令找不到
akonadiserver: コマンドが見つかりません