@scottalanmiller said in Slow SSH Logins on Linux:

Often remote SSH logins on Linux can experience a lengthy delay. This is often caused by the SSH daemon on the server defaulting to attempting a DNS lookup of the SSH client attempting to connect to it. Typically we do not want this behaviour as client systems often cannot be verified in this manner but awaiting a DNS timeout can be rather annoying. Many systems configure this on by default. I see this in the Red Hat family including RHEL, CentOS, etc.

The fix is simple, just explicetly add the line:

UseDNS no

To the /etc/ssh/sshd_config configuration file. The default is “yes” and there should be a comment to this effect as well. After making the change, simply restart the SSH daemon for the change to take effect.

service sshd restart

Originally found in 2012 on my Linux blog here: http://web.archive.org/web/20140822224153/http://www.scottalanmiller.com/linux/2012/09/02/slow-ssh-logins/

Ran into this the other day. Windows to Linux was pretty slow, but Linux to Linux (using our Bind server) was super fast. Turned off DNS and GSSAPI and it was fine from Windows.

@dafyre said in Linux: The Role of DRBD:

@scottalanmiller said in Linux: The Role of DRBD:

I added a header into the main topic list for that. But it is going to be later in the Advanced Topics, section. Oddly, I know of pretty much no standard Linux Administration tomes that cover DRBD. It's so core, very odd that it so often gets missed.

Could it be that most Linux Admin's don't know about it until they go searching for it? ...That's how I found out about it.

You would hope that the people writing the books would know, though!

What I think of every time I hear the phrase "kernel panic":

Youtube Video

@poorizad said in Storing Elastix 2 Call Recordings on NFS NAS Share:

@scottalanmiller hi again....i guess the nfs drive is unmount from the server, because no file record on Nas after the 2016/07/28.....nothing changed on settings.....but a few server shutdown for hardware maintenance.....how can i fix it again ?

Try the mount command again. It might mount right up. If the NFS server has restarted, it would disconnect.