dm_dso_reg_tool: 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:

/sbin/dm_dso_reg_tool - from package: dmraid-events

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

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