Rsync: Preserve / Copy Hard Links ( Backup Rsnapshot Directory Tree )

Posted on in Categories , , , , , , , last updated September 8, 2015

I‘m using rsnapshot filesystem snapshot utility to make incremental snapshots of local and remote filesystems for 10 production servers running on RHEL 5.x system. The rsnapshot commands makes extensive use of hard links, so if the file doesn’t change, the next snapshot is simply a hard link to the exact same file. How do I use the rsync command to copy my the entire snapshot directory /raid6/rsnapshot/ (around 4TB) to a remote server for mirroring purpose?

Linux / Unix: Disable OpenSSH Host Key Checking

Posted on in Categories last updated December 30, 2011

I‘ve a remote Unix server running with OpenSSH remote login service. The openssh is configured for passwordless login using ssh keys. Our ISP allows to boot all Linux servers into the rescue mode. It allow us to bring a server online remotely in order to troubleshoot system problems that would normally only be resolved by an OS Reload (such as accidentally deleting files or wrong firewall configurations blocking ssh access). When server boots into a remote rescue mode I can connect using SSH. They SSH keys will not be the same in the rescue mode so I get key mismatch messages as SSH keys are re-generated on each boot:

Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
Please contact your system administrator.
Add correct host key in /home/user/.ssh/known_hosts to get rid of this message.
Offending key in /home/user/.ssh/known_hosts:1
RSA host key for has changed and you have requested strict checking.
Host key verification failed.

How do I ignore OpenSSH hos key checking from my Apple OS X laptop while login using the ssh?

Linux / UNIX: scp / rsync File Name With a Colon (:) In It

Posted on in Categories , , last updated February 23, 2014

How do I copy a file with a colon punctuation (:) name in it. When I type the following command to copy “file:name.txt” to a remote host called server1:

scp file:name.txt user@server1:/path

I get the following error:

ssh: Could not resolve hostname s: Name or service not known

How do I copy file with scp or rsync with a colon in it?