案例環境：oracle linux server release 5.7
進入oracle linux系統後，在右上角點選聲音圖示時，則會彈出如下報錯視窗：
the volume control did not find any elements and/or devices to control . this means either that you don't have the right gstreamer plugins installed , or that you don't have a sound card configured .you can remove the volume control from the panel by right-clicking the speaker icon on the panel and selecting "remove from panel" from the menu"
no volume control gstreamer plugins and/or devices found
出現這個錯誤，有可能是下面幾種情況：
1: 使用者失去了通路audio裝置的權限。
2：相關包package沒有安裝。
3：伺服器本身就沒有聲霸卡裝置
我碰到的就是這種情況，如下所示，虛拟機（vmware)設定選項。
既然沒有聲霸卡裝置，那麼滑鼠指向聲音圖示，單擊右鍵彈出如下視窗，單擊“remove from panel”将聲音圖示從菜單欄移除。