Ubuntu ssh 每天第一次登陆奇慢无比

[xuboying]

我的 ubuntu server 版运行在家用虚拟机上，我发现每天第一次登陆总是非常慢，要 7 到 8 秒才出现下面内容，之后就快一些， 3 秒左右，是不是这个屏幕的信息读取导致了启动慢？
但这个信息还是有用的，比如上次登录 IP 之类的

他会在这个时刻去检查更新导致变慢么？
74 packages can be updated.
52 updates are security updates.



Welcome to Ubuntu 14.04.4 LTS (GNU/Linux 4.2.0-27-generic x86_64)

* Documentation: https://help.ubuntu.com/

System information as of Sat Apr 23 00:42:30 CST 2016

System load: 0.08 Processes: 101
Usage of /: 10.2% of 16.86GB Users logged in: 0
Memory usage: 61% IP address for eth0: yyyyyyyy
Swap usage: 0%

Graph this data and manage this system at:
https://landscape.canonical.com/

74 packages can be updated.
52 updates are security updates.

Last login: Sat Apr 23 00:42:40 2016 from gggggggg

解决了，是 mot 的原因，和 dns 关系不是太大


https://askubuntu.com/questions/23246/how-do-i-edit-the-ssh-motd

全部禁用以后就快了,缺点是没 ssh 后没信息了


qqqqqqq@ubuntu:/etc/update-motd.d$ time /usr/bin/landscape-sysinfo
System load: 0.32 Processes: 101
Usage of /: 10.0% of 16.86GB Users logged in: 1
Memory usage: 61% IP address for eth0: 192.168xxxxx
Swap usage: 0%

Graph this data and manage this system at:
https://landscape.canonical.com/

real 0m2.329s
user 0m1.844s
sys 0m0.480s


qqqqqq@ubuntu:/etc/update-motd.d$ find
.
./disable
./disable/50-landscape-sysinfo
./disable/90-updates-available
./disable/91-release-upgrade
./disable/98-reboot-required
./disable/10-help-text
./disable/98-fsck-at-reboot
./disable/00-header

[402124773]

之前到网上看到过一个相关的问题分析，最后的原因好像是 DNS 网络的原因导致的，时间长了也不记得哪里看到的了

[Septembers]

see http://www.cnblogs.com/ggjucheng/p/3348499.html
主要原因是 GSSAPI 导致

[xuboying]

@Septembers 不是这个问题，慢是密码输入以后

[ETiV]

sshd_config 里加个 UseDNS no 再重启 ssh 看看？

[xuboying]

@ETiV 我改了一台，明天看效果

[neilp]

应该是 dns 的问题。 先检查一下 服务器上那个的能正常解析域名吗. 我也遇到过

[Tink]

我跟你一样

[jackroyal]

@402124773 应该是这个<网络分析就是这么简单>
https://community.emc.com/community/support/chinese/teamblog/blog/2016/03/18/%E5%A4%A7%E5%92%96%E8%AE%B2%E7%BD%91%E7%BB%9C-linux%E4%B8%BA%E4%BB%80%E4%B9%88%E5%8D%A1%E4%BD%8F%E4%BA%86

[402124773]

@jackroyal
好像是这个文章，随便看看的，看完就忘了。
ssh ， scp ， rsync 确实是很方便的命令

[Tink]

应该是 dns ，我把服务器 ip 加到 hosts 里之后快多了

[akira]

域名反向解析的原因吧

[xuboying]

@402124773 @ETiV @Septembers @Tink @jackroyal @neilp

解决了，是 mot 的原因，和 dns 关系不是太大


https://askubuntu.com/questions/23246/how-do-i-edit-the-ssh-motd

全部禁用以后就快了,缺点是没 ssh 后没信息了


qqqqqqq@ubuntu:/etc/update-motd.d$ time /usr/bin/landscape-sysinfo
System load: 0.32 Processes: 101
Usage of /: 10.0% of 16.86GB Users logged in: 1
Memory usage: 61% IP address for eth0: 192.168xxxxx
Swap usage: 0%

Graph this data and manage this system at:
https://landscape.canonical.com/

real 0m2.329s
user 0m1.844s
sys 0m0.480s


qqqqqq@ubuntu:/etc/update-motd.d$ find
.
./disable
./disable/50-landscape-sysinfo
./disable/90-updates-available
./disable/91-release-upgrade
./disable/98-reboot-required
./disable/10-help-text
./disable/98-fsck-at-reboot
./disable/00-header

[whatisnew]

如果不装 `ubuntu standard system utilities` 就没事