Backup Size is smaller then actual backup path

[fadzlirot]

Hi,
Why is the backup size is smaller than actaully path? i backed up a path with size 7.27GB (using the df -g command) and when it is completed, the backup is only 3.14GB. No error reported and compression is 0. Only have 4.57% reduction ratio which i understand since the inspected is only 3.29GB

du -g (i take the last part of it)

0.01 /dump_log/xml_bkup/xml_from_tnslsnr/xml/8Jun2015
0.53 /dump_log/xml_bkup/xml_from_tnslsnr/xml
0.53 /dump_log/xml_bkup/xml_from_tnslsnr
0.02 /dump_log/xml_bkup/xml_from_trace
0.55 /dump_log/xml_bkup
7.27 /dump_log/

Normal File--> 331,684 /dump_log/xml_bkup/xml_from_trace/log_8.xml.gz [Sent]
Normal File--> 332,028 /dump_log/xml_bkup/xml_from_trace/log_9.xml.gz [Sent]
Selective Backup processing of '/dump_log/*' finished without failure.


Total number of objects inspected: 1,269,635
Total number of objects backed up: 1,269,635
Total number of objects updated: 0
Total number of objects rebound: 0
Total number of objects deleted: 0
Total number of objects expired: 0
Total number of objects failed: 0
Total number of objects encrypted: 0
Total number of objects grew: 0
Total number of retries: 0
Total number of bytes inspected: 3.29 GB
Total number of bytes transferred: 3.14 GB
Data transfer time: 39.67 sec
Network data transfer rate: 83,109.94 KB/sec
Aggregate data transfer rate: 2,864.27 KB/sec
Objects compressed by: 0%
Total data reduction ratio: 4.57%
Elapsed processing time: 00:19:11

 

[marclant]

What OS?
What's the full "du ..." command you used?
What's the full "dsmc sel ..." command you used?

 

[fadzlirot]

What OS?
What's the full "du ..." command you used?
What's the full "dsmc sel ..." command you used?

AIX
i used du -g /dump_log/ to see the dump_log size.
i used the dsmc s -optfile=dsmdumplog.opt -subdir=yes /dump_log/ >> /usr/tivoli/tsm/client/ba/bin64/schedlogs/dumplog.log

 

[marclant]

I got curious and did a test, I got similar results:


I did mine in K instead of G due to the size, but still can't explain the 2:1 difference.