akonadi_rds: command not found

Have You tried accessing the binary with the full path?

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 Debian possible default full paths are:

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

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