Hi All,<br><br>I am presently doing a small POC with rsync for incremental backup and restore starategies.<br><br>I have come up with certain question down the line, can anyone help me with the explanation.<br><br>Used the config and ideas from: <br clear="all">
<a href="http://www.mikerubel.org/computers/rsync_snapshots/" target="_blank">http://www.mikerubel.org/computers/rsync_snapshots/</a><br><br><br>The commands executed on two machines in sequence<br><br>Machine 1:<br>root@Andruil:~# vim testfile<br>
root@Andruil:~# ls -lh testfile <br>-rw-r--r-- 1 root root 71 2011-02-07 17:10 testfile<br>root@Andruil:~# rsync -avh testfile vxadmin@192.168.155.151:/tmp --stats --progress<br><a href="mailto:vxadmin@192.168.155.151" target="_blank">vxadmin@192.168.155.151</a>'s password: <br>
sending incremental file list<br>testfile<br> 71 100% 0.00kB/s 0:00:00 (xfer#1, to-check=0/1)<br>sent 147 bytes received 31 bytes 20.94 bytes/sec<br>total size is 71 speedup is 0.40<br><br>Machine 2:<br>
vxadmin@vx64:/tmp$ ls -lh testfile <br>-rw-r--r-- 1 vxadmin vxadmin 71 2011-02-07 17:10 testfile<br>vxadmin@vx64:/tmp$ cp -al testfile testfile_bak1<br>vxadmin@vx64:/tmp$ ls -ilh testfile*<br>140822 -rw-r--r-- 1 vxadmin vxadmin 71 2011-02-07 17:33 testfile<br>
140822 -rw-r--r-- 1 vxadmin vxadmin 71 2011-02-07 17:10 testfile_bak1<br><br>Machine 1:<br>root@Andruil:~# vim testfile<br>
root@Andruil:~# ls -lh testfile <br>
-rw-r--r-- 1 root root 159 2011-02-07 17:33 testfile<br>
root@Andruil:~# rsync -avh testfile vxadmin@192.168.155.151:/tmp --stats --progress<br><a href="mailto:vxadmin@192.168.155.151" target="_blank">vxadmin@192.168.155.151</a>'s password: <br>sending incremental file list<br>
testfile<br>
159 100% 0.00kB/s 0:00:00 (xfer#1, to-check=0/1)<br>sent 168 bytes received 37 bytes 45.56 bytes/sec<br>total size is 159 speedup is 0.78<br>vxadmin@vx64:/tmp$ ls -ilh testfile*<br>140822 -rw-r--r-- 1 vxadmin vxadmin 159 2011-02-07 17:33 testfile<br>
140823 -rw-r--r-- 1 vxadmin vxadmin 71 2011-02-07 17:10 testfile_bak1<br><br><br>As from this output i came to understand that when new update is written to the backup, the first backup file hardlink is destroyed and a new file is created. <br>
Is it how this works or am i missing anything here. I have performed these operations with large qcow2 images also.<br><br>I came to a conclusion that this incremental concept is good, taking into consideration that only the delta is transferred.<br>
<br>Is there anyway in which i can have only the delta of the original file be present at the backup location.<br>something like <br>1. 1st backup is 100M <br>2. write 20MB to the original file<br>3. do a sync using hardlinks <br>
4. i have 20MB file at backup location with the delta changes only.<br><br><br>Mani<br><br><br>-- <br>K Manikanta Swamy<br>+919059014442<br>