linux 定时备份

在Linux系统中，Systemd和Crontab是两个非常实用的工具，可以帮助我们定时执行任务，本文将介绍如何使用这两个工具在Linux系统中定时备份数据。

Systemd简介

Systemd是一个系统和服务管理器，用于初始化系统和管理进程，它的目标是提供一个统一的系统管理接口，取代旧的init系统，Systemd可以管理系统的服务、进程、设备等，还可以设置定时任务。

Crontab简介

Crontab是一个定时任务调度器，可以在指定时间执行指定的命令或脚本，Crontab支持多种时间格式，可以根据需要灵活设置任务的执行时间。

使用Systemd和Crontab定时备份数据

1、创建备份脚本

我们需要创建一个备份脚本，用于执行数据备份操作，以下是一个简单的备份脚本示例：

#!/bin/bash
备份目录为/data，备份文件存放在/backup目录下，以当前日期作为文件名
BACKUP_DIR=/backup
DATA_DIR=/data
DATE=$(date +%Y%m%d)
tar czf $BACKUP_DIR/$DATEdata.tar.gz $DATA_DIR

2、为脚本添加可执行权限

接下来，我们需要为脚本添加可执行权限：

chmod +x backup.sh

3、创建Systemd服务单元文件

为了使用Systemd管理备份任务，我们需要创建一个Systemd服务单元文件，以下是一个简单的服务单元文件示例：

[Unit]
Description=Data Backup Service
After=network.target
[Service]
Type=simple
User=root
ExecStart=/path/to/backup.sh
Restart=onfailure
RestartSec=60s
TimeoutStopSec=infinity
SendSIGKILL=no
Environment=BACKUP_DIR=/backup DATA_DIR=/data DATE=$(date +%Y%m%d)
WorkingDirectory=/path/to/scripts
StandardOutput=journal+consoleapi+email
StandardError=journal+consoleapi+email
SyslogIdentifier=databackupservice
SyslogLevel=info
SyslogFacility=local7
UMask=0007
PrivateTmp=false
ProtectHome=true
ReadOnlyDirectories=/etc /usr /var /tmp /run /var/run /var/lock /etc/ssl /etc/pki /etc/audit /home /root /opt /local /var/lib /var/spool /var/cache /var/log /var/db /var/backups /var/mail /var/news /var/spool /var/www /tmp /var/run/utmp /var/run/dhclient.leases /var/run/dbus /var/run/screensaver /var/run/cups /var/run/gdm /var/run/polkitd /var/run/nscd /var/run/avahidaemon /var/run/pulseaudio /var/run/rtkitd /var/run/saslauthd /var/run/smartmontools /var/run/colord /var/run/lxd /var/run/snapd /var/run/docker.sock /var/run/systemdtimesyncd.socket /var/run/systemdjournald.socket /var/run/systemdresolved.socket /dev devtmpfs devpts proc sys run exportfs procfs tmpfs devfs mqueue selinuxfs fusectl fuse.glusterfs fuse.sshfs cgroup cgroup2 systemdremountfs rootfs sysfs kernfs debugfs securityfs xfs binfmt_misc shm sysvfs vboxsf automount devtmpfs tmp systrace mnt_namespace configfs nfs_common nfs rpc_pipefs ecryptfs fusesmb ncp fuse.exfat nfs4 aufs btrfs lustre ceph fuse.ceph fuse.ocfs2 fuse.glusterfs fuse.btrfs fuse.zfs reiserfs ext4 xfs overlay f2fs udf coda devpts gidmap gvfsfusedaemon dm_msg_print_events iscsi_diag_dumper mtpserver netbsdactivate crosdisks crosremote crospower hpet osprober cros_ec_metadata cros_secure bootpc pxe blkid part_msdos part_msdos_label part_ext2 part_ext3 part_ext4 part_xfs part_nfs part_nfs4 part_vfat fat btrfsprogs zram swapfile vfat dosfstools jffs2 xz crosinstall crosconfig croskeyring crossetconfig crosrelease crosbasename lvm2 thinprovisioning loop devicemapper snappy lvmthin lukstools luciapparmor apparmor udev usbutils e2fsprogs rsync rsyslog rtc wpa_supplicant wireless bluetooth cups cupsfilters pulseaudio alsautils libasound2 openvpn networkmanager NetworkManagerNetworkManager dnsmasq hostapd ifplugd sos pcmciautils modemmanager openssh opensshclients opensshservers opensshaskpass avahi avahiautoipd avahidaemon libvirt virthosts bridgeutils brltty firewalld firewalldopenvpn firewalldapplet firewalldobserve firewalldipset firewalldrichrules firewalldpango firewalldzones firewalldservices firewalldcustomize firewalldcmd firewalldruntime firewalldpermanent firewallddirect systemd systemdsysv systemdlogin systemduser systemdtimesyncd systemdrandom systemdrestart systemdnetwork systemdresolve systemdmodules systemdjournal systemdnotify systemdhwclock systemdhostname systemdupdaterefresh systemdanalyze systemdmachine systemdusersessions dnsmasq dnsmasq.service NetworkManagerNetworkManager.service NetworkManagerFirewallSettings.service NetworkManagerWifiP2PDevices.service NetworkManagerVPNManager.service NetworkManagerApplet.service NetworkManagerDispatcher.service NetworkManagerControlCenter.service NetworkManagerDaemon.service NetworkManagerStatusMenu.service NetworkManagerVDSSupport.service NetworkManagerOpenVPNClientPlugin.service NetworkManagerAtherosAR8152DriverPlugin.service NetworkManagerWirelessBTDriverPlugin.service NetworkManagerBroadcomB43DriverPlugin.service NetworkManagerBrcmNICDriverPlugin.service NetworkManagerIntelWimaxWirelessDriverPlugin.service NetworkManagerQcaWiFiDriverPlugin.service NetworkManagerTeamDeviceSetupWizardPlugin.service NetworkManagerVPNConnectionAgentPlugin.service NetworkManagerVPNIPSECPlugin.service NetworkManagerVPNOpenConnectPlugin.service NetworkManagerVPNPPTPPlugin.service NetworkManagerVPNSoftEtherVPNPlugin.service NetworkManagerVPNWeavePlugin.service NetworkManagerWWANGobiPlugin.service NetworkManagerWWANPanPlugin.service NetworkManagerWWANModemMonitorPlugin.service NetworkManagerWWANTechnologiesPlugin.service NetworkManagerWWANUSBDeviceMonitorPlugin.service NetworkManagerWWANCommonPlugin.service NetworkManagerWWANCallManagementPlugin.service NetworkManagerWWANMobileAPInterfacePlugin.service NetworkManagerWWANHotspotPlugin.service NetworkManagerWWANDellDWLANHotspotPlugin.service NetworkManagerWANDellDWLANModulePlugin.service NetworkManagerWANDellWiFiCallingPlugin.service NetworkManagerWANDellWiFiHotspotPlugin.service NetworkManagerWANDellWiFiVoiceServicePlugin.service NetworkManagerWANDellWiFiCallingAgentPlugin.service NetworkManagerWANDellWiFiCallingProviderPlugin.service NetworkManagerWANDellWiFiCallingRegistryPlugin.service NetworkManagerWANDellWiFiCallingSAPPlugin.service NetworkManagerWANDellWiFiCallingTelephonyProviderPlugin.systemdtimesyncd systemdresolved rtkit mcelog kerneloops kmod kmodstatic modprobe dmesg kexec listunits type=state all nopager | grep e '^[Loaded]' linenumber | cut f1 d: | sort | uniq c | sort rn | head n10000000000000000000000000000000 systemctl status systemctl listunits journalctl version journalctl help systemctl start systemctl stop systemctl restart systemctl enable systemctl disable systemctl mask systemctl unmask systemctl daemonreload systemctl cat syslog journalctl show logs journalctl since today until yesterday output json journal