Rsync: Performance NFS Boost

If you use two Linux Servers with NFS Shares connect over Gigabit Interfaces for Backups, you perhaps remark performance problems on using rsync.
It does often pause transmissions or reach only a rate of 32Mb/s. That’s bad and waste time and energy.

Background:
After some Tests of running Backups with single files and compressed big archives, the scans of my tools like iftop, systat, iptraf found out that the used Option „rsync -avz“ was the bottle neck, cause the Data Rate break down at intervals. The „z“ compress option was described on howtos as must have for slower networks did not work like a „on the fly permanent transmission“. My two Test Servers use each 3 Gigabit bonded NIC Cards, if the rsync command compress the Files, they were first pulled to RAM Cache and compressed there later after a small pause send.

Solution:
If you disable and remove the „z“ option and on used bash scripts as „batch run“ removing the „v“ Option too, i was able to send Data at range of 133MB/s.

On fast Network do:

$rsync -a /source/ /nfs-mounted-destination

GDM3: Change Wallpaper Change background color Speed up GDM3 after boot

Problem: By default Debian with GDM3 is slow on older Hardware like Laptops or PCs with small Graphic Card

Background: GDM3 shows Images at size 800×600 an zooms up to Screen Size, this burns speed.

Solution:
edit gdm3-theme config

sudo nano /usr/share/gdm/greeter-config/20_debian

and change to
#Use a specific background
#/desktop/gnome/background/picture_filename     /..path #to wallpaper
#/desktop/gnome/background/picture_options      zoom #zoom
/desktop/gnome/background/primary_color #357DAA  # color Win2000 

# Theming options
#/desktop/gnome/interface/gtk_theme             Clearlooks

# Greeter options
#/apps/gdm/simple-greeter/logo_icon_name        debian-swirl

# Play system beeps - especially the one when the greeter is ready
#/desktop/gnome/sound/event_sounds              true

# Some other possible options
#/apps/gdm/simple-greeter/banner_message_enable         true
#/apps/gdm/simple-greeter/banner_message_text           Welcome
#/apps/gdm/simple-greeter/disable_restart_buttons       false
#/apps/gdm/simple-greeter/disable_user_list             false

# The lower panel doesn't work with the compositor
/apps/metacity/general/compositing_manager              false

# Prevent the power management icon from showing up
/apps/gnome-power-manager/ui/icon_policy                never


reboot and enjoy…

Additional Info:

  • Install „metacity“ window manager its needed by gdm3 too on openbox or LXDE Desktops
  • If „desktop-base“ is not installed the gdm3 background is shown lime green then create a empty file named
  • sudo nano  /usr/share/gdm/greeter-config/10_desktop-base

Fritzbox: DNS lookup slow

Problem:

Wenn man mit einem PC hinter eine Router z.b. fritzbox 7170 sitzt kann das anfordern von Internetseiten (http://www.usw…) länger dauern. Grund Ihr Internetprovider besitzt DNS-Namensauflösungsserver die unter hoher Last z.B. viele DSL-Kunden leiden.

Das Problem besteht weiter darin das Ihr DSL-Router dynamisch diese DNS-Server mitgeteilt bekommt und Sie diese nicht manuell ändern können (ander Fabrikate ausgenommen)

Lösung:

Sie richten auf Ihrem PC unter Netzwerkeinstellugen neue zusätzliche DNS Servereinträge ein und nutzen diese an erster Stelle

öffenen Sie die Datei /etc/resolv.conf (für Windows Nutzer siehe Netzwerk)

und einfügen

nameserver 208.67.222.222 #OPENDNS POWER SERVER
nameserver 208.67.220.220
nameserver 192.168.178.1 #Router

nun sollten Sie das Verhalten in den nächsten Tagen testen.


Behind a dsl-router you have the problem with slow internet site requests in your browser, this is a result of the poor performance of the provider dns servers. In fact that your router hardware does not have the possibility to setup own dns-server adresses, your are forced to setup additional dns addresses in your pc.on linux edit /etc/resolv.conf see above with opendns power server addresses