Wer einen Xen-virtualisierten Server betreibt staunt manchmal nicht schlecht, wie langsam die Server-Uhr geht. Am Anfang sind es wenige Sekunden. Irgendwann ist es schon eine Minute…<\/p>\n
Es gibt Software, die dies beheben k\u00f6nnte, aber sie scheint nicht zu funktionieren. Egal wie oft man versucht, die Zeit neu einzustellen – es geht nicht.<\/p>\n
<\/p>\n
Die Ursache liegt darin, dass Xen versucht, die System-Zeit der Hardware zu nutzen (genauer gesagt, den Sysclock des Wirtes). Diese kann man nat\u00fcrlich aus dem Xen-Gast heraus nicht setzen. Doch es gibt einen anderen Weg: Man schaltet im Xen einen eigenen Sysclock ein. Das geht mit root-Rechten sehr schnell:<\/p>\n
echo 1 > \/proc\/sys\/xen\/independent_wallclock<\/span><\/pre>\nDanach ist ein Zeitabgleich von dauer – der Sysclock des Xen-Systems l\u00e4sst sich setzen. ZB mit:<\/p>\n
\/usr\/sbin\/ntpdate europe.pool.ntp.org<\/span><\/pre>\nDamit man die \u00dcbung nicht immer per Hand exerzieren muss, schafft man eine neue Datei an und gibt Folgendes ein:<\/p>\n
#!\/bin\/bash\n<\/span>echo 1 > \/proc\/sys\/xen\/independent_wallclock\n\/usr\/sbin\/ntpdate europe.pool.ntp.org<\/span><\/pre>\nSpeichern + chmod 700<\/strong> macht es zu einem Pseudo-Programm. Jetzt nur noch den vollen Pfad zu dieser Datei im crontab eintragen (oder unter Debian\/Ubunut<\/strong> die Datei in \/etc\/cron.daily\/<\/strong> ablegen). Und schon k\u00fcmmert sich der Server selber um seine Zeit-Updates.<\/p>\n","protected":false},"excerpt":{"rendered":"Wer einen Xen-virtualisierten Server betreibt staunt manchmal nicht schlecht, wie langsam die Server-Uhr geht. Am Anfang sind es wenige Sekunden. Irgendwann ist es schon eine Minute… Es gibt Software, die dies beheben k\u00f6nnte, aber sie scheint nicht zu funktionieren. Egal wie oft man versucht, die Zeit neu einzustellen – es geht nicht.<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_sitemap_exclude":false,"_sitemap_priority":"","_sitemap_frequency":"","ocean_post_layout":"","ocean_both_sidebars_style":"","ocean_both_sidebars_content_width":0,"ocean_both_sidebars_sidebars_width":0,"ocean_sidebar":"","ocean_second_sidebar":"","ocean_disable_margins":"enable","ocean_add_body_class":"","ocean_shortcode_before_top_bar":"","ocean_shortcode_after_top_bar":"","ocean_shortcode_before_header":"","ocean_shortcode_after_header":"","ocean_has_shortcode":"","ocean_shortcode_after_title":"","ocean_shortcode_before_footer_widgets":"","ocean_shortcode_after_footer_widgets":"","ocean_shortcode_before_footer_bottom":"","ocean_shortcode_after_footer_bottom":"","ocean_display_top_bar":"default","ocean_display_header":"default","ocean_header_style":"","ocean_center_header_left_menu":"","ocean_custom_header_template":"","ocean_custom_logo":0,"ocean_custom_retina_logo":0,"ocean_custom_logo_max_width":0,"ocean_custom_logo_tablet_max_width":0,"ocean_custom_logo_mobile_max_width":0,"ocean_custom_logo_max_height":0,"ocean_custom_logo_tablet_max_height":0,"ocean_custom_logo_mobile_max_height":0,"ocean_header_custom_menu":"","ocean_menu_typo_font_family":"","ocean_menu_typo_font_subset":"","ocean_menu_typo_font_size":0,"ocean_menu_typo_font_size_tablet":0,"ocean_menu_typo_font_size_mobile":0,"ocean_menu_typo_font_size_unit":"px","ocean_menu_typo_font_weight":"","ocean_menu_typo_font_weight_tablet":"","ocean_menu_typo_font_weight_mobile":"","ocean_menu_typo_transform":"","ocean_menu_typo_transform_tablet":"","ocean_menu_typo_transform_mobile":"","ocean_menu_typo_line_height":0,"ocean_menu_typo_line_height_tablet":0,"ocean_menu_typo_line_height_mobile":0,"ocean_menu_typo_line_height_unit":"","ocean_menu_typo_spacing":0,"ocean_menu_typo_spacing_tablet":0,"ocean_menu_typo_spacing_mobile":0,"ocean_menu_typo_spacing_unit":"","ocean_menu_link_color":"","ocean_menu_link_color_hover":"","ocean_menu_link_color_active":"","ocean_menu_link_background":"","ocean_menu_link_hover_background":"","ocean_menu_link_active_background":"","ocean_menu_social_links_bg":"","ocean_menu_social_hover_links_bg":"","ocean_menu_social_links_color":"","ocean_menu_social_hover_links_color":"","ocean_disable_title":"default","ocean_disable_heading":"default","ocean_post_title":"","ocean_post_subheading":"","ocean_post_title_style":"","ocean_post_title_background_color":"","ocean_post_title_background":0,"ocean_post_title_bg_image_position":"","ocean_post_title_bg_image_attachment":"","ocean_post_title_bg_image_repeat":"","ocean_post_title_bg_image_size":"","ocean_post_title_height":0,"ocean_post_title_bg_overlay":0.5,"ocean_post_title_bg_overlay_color":"","ocean_disable_breadcrumbs":"default","ocean_breadcrumbs_color":"","ocean_breadcrumbs_separator_color":"","ocean_breadcrumbs_links_color":"","ocean_breadcrumbs_links_hover_color":"","ocean_display_footer_widgets":"default","ocean_display_footer_bottom":"default","ocean_custom_footer_template":"","ocean_post_oembed":"","ocean_post_self_hosted_media":"","ocean_post_video_embed":"","ocean_link_format":"","ocean_link_format_target":"self","ocean_quote_format":"","ocean_quote_format_link":"post","ocean_gallery_link_images":"on","ocean_gallery_id":[],"footnotes":""},"categories":[8],"tags":[65,74,96],"class_list":["post-104","post","type-post","status-publish","format-standard","hentry","category-software","tag-linux","tag-opensource","tag-server","entry"],"_links":{"self":[{"href":"https:\/\/blog.kolatzek.org\/wblog\/wp-json\/wp\/v2\/posts\/104","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.kolatzek.org\/wblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.kolatzek.org\/wblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.kolatzek.org\/wblog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.kolatzek.org\/wblog\/wp-json\/wp\/v2\/comments?post=104"}],"version-history":[{"count":0,"href":"https:\/\/blog.kolatzek.org\/wblog\/wp-json\/wp\/v2\/posts\/104\/revisions"}],"wp:attachment":[{"href":"https:\/\/blog.kolatzek.org\/wblog\/wp-json\/wp\/v2\/media?parent=104"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.kolatzek.org\/wblog\/wp-json\/wp\/v2\/categories?post=104"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.kolatzek.org\/wblog\/wp-json\/wp\/v2\/tags?post=104"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}