[CentOS] Yum update changes inode of file

Fri Aug 22 21:13:40 UTC 2014
Meikel <meikel_b at web.de>

Hi folks,

on CentOS 6.5 I run tripwire software which verifies data integrity. My 
system is automatically updated by yum (as far as I understand the 
/etc/cron.daily/0yum.cron is responsible for the regular system 
updates). After a system update I'm then notified by tripwire about the 
changes on the file system.

By browsing those tripwire reports I found that there are files which 
did not change at all (i.e. the MD5 hash is the same as before) but the 
inode changed. I do not understand what yum did to the file that 
resulted in an inode change, especially I'm wondering how the inode can 
change although there was no modification on the file at all.

Thanks in advance for any clarification.

Find below an excerpt from the tripwire log (for /etc/nsswitch.conf) 
which shows that only inode changed.

Regards,

Meikel




Excerpt from tripwire report:

Modified object name:  /etc/nsswitch.conf

   Property:            Expected                    Observed
   -------------        -----------                 -----------
   Object Type          Regular File                Regular File
   Device Number        64770                       64770
* Inode Number         393292                      393686
   Mode                 -rw-r--r--                  -rw-r--r--
   Num Links            1                           1
   UID                  root (0)                    root (0)
   GID                  root (0)                    root (0)
   Size                 1688                        1688
   Modify Time          Tue 04 May 2010 09:22:21 PM CEST
                                                    Tue 04 May 2010 09:22:21 PM CEST
   Blocks               8                           8
   CRC32                DjDI7W                      DjDI7W
   MD5                  ANYAnN/RJkbSUehjA7wMSM      ANYAnN/RJkbSUehjA7wMSM