UNIX sparse file
Posted: Wed May 22, 2013 3:03 pm
When rsyncing from laxm1711 to laxm1811, I found vertexTST file system on laxm1811 is 4 GB larger than on 1711.
After digging deeper, I found the following file that is worth checking:
Same file, same size from `ls -l` but `du` shows different size.
Later on, when checking with Carsten Clasohm (Redhat consultant), he thought it is a sparse file.
In order for rsync to copy sparse files, I have to add a flag of "-S or --sparse" according to man page.
Lesson learned!
After digging deeper, I found the following file that is worth checking:
Code: Select all
-rw-r----- 1 oratst dba 4294975488 May 17 22:00 /oracle/vertexTST/data/temp.data1
[root@laxm1711 data]# du -h temp.data1
984K temp.data1
On the VM C460, it reports correctly:
[root@laxm1331 data]# du -h temp.data1
4.1G temp.data1
Later on, when checking with Carsten Clasohm (Redhat consultant), he thought it is a sparse file.
I checked with Mohan yesterday and he confirmed the app created the sparse file.Hi Chang,
I guess that temp.data1 is a sparse file. You can check that as described on
http://en.wikipedia.org/wiki/Sparse_fil ... es_in_Unix
If you had used the "--sparse" option for rsync, it would consume the same amount of space on the target system.
Carsten
In order for rsync to copy sparse files, I have to add a flag of "-S or --sparse" according to man page.
Code: Select all
-S, --sparse handle sparse files efficiently