chapter.faq.xml

<?xml version="1.0" encoding="UTF-8"?>
<chapter id="index"><?dbhtml dir="faq" ?>
	<title>FAQ</title>
	<section id="ssh">
		<title>通过SSH与控制台不能登录</title>
		<para>通过SSH与控制台不能登录，登录后立即退出。</para>
		<para>我在做压力测试的时候将所有用户的 nofile 设置为 1050000 导致 SSH 与控制台均不能登录Linux 系统。</para>
		<screen>
# cat /etc/security/limits.conf |tail
#*               hard    rss             10000
#@student        hard    nproc           20
#@faculty        soft    nproc           20
#@faculty        hard    nproc           50
#ftp             hard    nproc           0
#@student        -       maxlogins       4

# End of file
* soft nofile 1050000
* hard nofile 1050000

		</screen>
		<para>后来发现/var/log/secure 日志，提示Could not set limit for 'nofile': Operation not permitted </para>
		<screen>
# tail -f /var/log/secure

Aug  6 04:07:56 r510 sshd[20858]: Accepted password for root from 192.168.80.129 port 51798 ssh2
Aug  6 04:07:56 r510 sshd[20858]: pam_limits(sshd:session): Could not set limit for 'nofile': Operation not permitted
Aug  6 04:07:56 r510 sshd[20858]: pam_unix(sshd:session): session opened for user root by (uid=0)
Aug  6 04:07:56 r510 sshd[20858]: error: PAM: pam_open_session(): Permission denied
		</screen>

		<screen>

		</screen>
		<para></para>
		<screen>

		</screen>
	</section>
</chapter>