# Ubuntu ## Generic ### Timezone ``` $ timedatectl list-timezones $ sudo timedatectl set-timezone Asia/Singapore $ date ``` ### How to Fix ‘E: Could not get lock /var/lib/dpkg/lock’ Error in Ubuntu Linux When trying to install components but saw this: `E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), is another process using it?` This may be some `apt-get install` process is happening: ``` $ ps aux | grep -i apt root 7025 0.0 0.0 2608 476 ? Ss 12:17 0:00 /bin/sh /usr/lib/apt/apt.systemd.daily install root 7029 0.0 0.0 2608 1656 ? S 12:17 0:00 /bin/sh /usr/lib/apt/apt.systemd.daily lock_is_held install bright 12846 0.0 0.0 8156 2580 pts/0 S+ 12:20 0:00 grep --color=auto -i ap ``` Just wait for a couple of minutes, it will be okay after the auto update process is done. To disable the auto update process: ``` $ sudo vi /etc/apt/apt.conf.d/20auto-upgrades APT::Periodic::Update-Package-Lists "0"; APT::Periodic::Unattended-Upgrade "0"; ``` ## Xenial - 16.04 LTS ### Enable dual network interfaces for VirtualBox ``` source /etc/network/interfaces.d/* # The loopback network interface auto lo iface lo inet loopback # The primary network interface # which maps to "Host-only adapter" auto enp0s3 iface enp0s3 inet dhcp # The secondary network interface # which maps to "NAT" auto enp0s8 #iface enp0s8 inet dhcp iface enp0s8 inet static address 192.168.56.101 network 192.168.56.0 netmask 255.255.255.0 gateway 192.168.56.1 dns-nameservers 8.8.8.8 192.168.56.1 ``` This setting leads to VMs provisioned on VirtualBox like this: * It can ping Internet through NAT from Host laptop; * It has a potential static IP if you want ``` enp0s3 Link encap:Ethernet HWaddr 08:00:27:d6:00:3d inet addr:192.168.56.101 Bcast:192.168.56.255 Mask:255.255.255.0 inet6 addr: fe80::a00:27ff:fed6:3d/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:226 errors:0 dropped:0 overruns:0 frame:0 TX packets:170 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:21419 (21.4 KB) TX bytes:21035 (21.0 KB) enp0s8 Link encap:Ethernet HWaddr 08:00:27:44:a1:a8 inet addr:10.0.3.15 Bcast:10.0.3.255 Mask:255.255.255.0 inet6 addr: fe80::a00:27ff:fe44:a1a8/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:38 errors:0 dropped:0 overruns:0 frame:0 TX packets:61 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:7129 (7.1 KB) TX bytes:5521 (5.5 KB) ``` ## Bionic - 18.04 LTS ### Enable dual network interfaces for VirtualBox Ref: ``` $ cd /etc/netplan/ $ cat 50-cloud-init.yaml network: version: 2 ethernets: enp0s3: dhcp4: yes $ sudo vi 50-cloud-init.yaml network: version: 2 ethernets: enp0s3: dhcp4: yes enp0s8: dhcp4: yes $ sudo netplan apply $ ifconfig enp0s3: flags=4163 mtu 1500 inet 192.168.56.107 netmask 255.255.255.0 broadcast 192.168.56.255 inet6 fe80::a00:27ff:fe2b:4295 prefixlen 64 scopeid 0x20 ether 08:00:27:2b:42:95 txqueuelen 1000 (Ethernet) RX packets 64 bytes 10751 (10.7 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 70 bytes 10955 (10.9 KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 enp0s8: flags=4163 mtu 1500 inet 10.0.3.15 netmask 255.255.255.0 broadcast 10.0.3.255 inet6 fe80::a00:27ff:fe7a:edcf prefixlen 64 scopeid 0x20 ether 08:00:27:7a:ed:cf txqueuelen 1000 (Ethernet) RX packets 14 bytes 2232 (2.2 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 42 bytes 3868 (3.8 KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 lo: flags=73 mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10 loop txqueuelen 1000 (Local Loopback) RX packets 1024 bytes 73520 (73.5 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 1024 bytes 73520 (73.5 KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 ``` ## Focal Fossa - 20.04 LTS ### Enable dual network interfaces for VirtualBox ``` $ sudo vi /etc/netplan/00-installer-config.yaml $ cat /etc/netplan/00-installer-config.yaml # This is the network config written by 'subiquity' network: ethernets: enp0s3: dhcp4: true enp0s8: dhcp4: true version: 2 $ sudo netplan try ``` This setting leads to VMs provisioned on VirtualBox like this: * It can ping Internet through NAT from Host laptop; * It has a potential static IP if you want ``` $ ip addr 1: lo: mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: enp0s3: mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether 08:00:27:4a:d7:4d brd ff:ff:ff:ff:ff:ff inet 192.168.56.105/24 brd 192.168.56.255 scope global dynamic enp0s3 valid_lft 848sec preferred_lft 848sec inet6 fe80::a00:27ff:fe4a:d74d/64 scope link valid_lft forever preferred_lft forever 3: enp0s8: mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether 08:00:27:36:40:11 brd ff:ff:ff:ff:ff:ff inet 10.0.3.15/24 brd 10.0.3.255 scope global dynamic enp0s8 valid_lft 86048sec preferred_lft 86048sec inet6 fe80::a00:27ff:fe36:4011/64 scope link valid_lft forever preferred_lft forever ``` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://brightzheng100.gitbook.io/tech-diary/operation-systems/ubuntu.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.