1). 기존 RPM 버전 확인 및 백업
#rpm -qa | grep glibc
compat-glibc-headers-2.3.4-2.26
glibc-common-2.5-81
glibc-devel-2.5-81
compat-glibc-2.3.4-2.26
compat-glibc-2.3.4-2.26
glibc-2.5-81
glibc-headers-2.5-81
glibc-devel-2.5-81
glibc-2.5-81

2). createrepo 명령어로 REPODATA 생성하기
( 작업 경로 : /usr/local/src/new_glibc )

# pwd
/usr/local/src/new_glibc

#createrepo ./
12/12 - glibc-devel-2.5-123.el5_11.1.i386.rpm                                  
Saving Primary metadata
Saving file lists metadata
Saving other metadata

3). old_glibc.repo 경로 생성
#vim /etc/yum.repos.d/new_glibc.repo
[old-glibc]
baseurl=file:///usr/local/src/new_glibc/
enabled=1
gpgcheck=0

4). 생성한 repo 확인
# yum repolist                      
Loaded plugins: katello, product-id, security, subscription-manager
Updating certificate-based repositories.
Repository 'new-glibc' is missing name in configuration, using id
Unable to read consumer identity
new-glibc|  951 B     00:00    
new-glibc/primary|  10 kB     00:00                 new-glibc12/12
repo id   repo name                                         status
new-glibc new-glibc                                             12
rhel-DVD  Red Hat Enterprise Linux 5Server - x86_64 - DVD    3,285
repolist: 3,297

5). yum 으로 업데이트 진행
# yum update glibc
Loaded plugins: katello, product-id, security, subscription-manager
Updating certificate-based repositories.
Repository 'new-glibc' is missing name in configuration, using id
Unable to read consumer identity
Skipping security plugin, no data
Setting up Update Process
Resolving Dependencies
Skipping security plugin, no data
--> Running transaction check
--> Processing Dependency: glibc = 2.5-81 for package: glibc-devel
--> Processing Dependency: glibc = 2.5-81 for package: glibc-headers
--> Processing Dependency: glibc = 2.5-81 for package: nscd
--> Processing Dependency: glibc = 2.5-81 for package: glibc-devel
---> Package glibc.i686 0:2.5-123.el5_11.1 set to be updated
--> Processing Dependency: glibc-common = 2.5-123.el5_11.1 for package: glibc
---> Package glibc.x86_64 0:2.5-123.el5_11.1 set to be updated
--> Running transaction check
---> Package glibc-common.x86_64 0:2.5-123.el5_11.1 set to be updated
---> Package glibc-devel.i386 0:2.5-123.el5_11.1 set to be updated
---> Package glibc-devel.x86_64 0:2.5-123.el5_11.1 set to be updated
---> Package glibc-headers.x86_64 0:2.5-123.el5_11.1 set to be updated
---> Package nscd.x86_64 0:2.5-123.el5_11.1 set to be updated
--> Finished Dependency Resolution

Dependencies Resolved

=====================================================================
Package           Arch   Version          Repository Size
=====================================================================
Updating:
 glibc            i686   2.5-123.el5_11.1 new-glibc  5.4 M
 glibc            x86_64 2.5-123.el5_11.1 new-glibc  4.8 M
Updating for dependencies:
 glibc-common     x86_64 2.5-123.el5_11.1 new-glibc   16 M
 glibc-devel      i386   2.5-123.el5_11.1 new-glibc  2.1 M
 glibc-devel      x86_64 2.5-123.el5_11.1 new-glibc  2.4 M
 glibc-headers    x86_64 2.5-123.el5_11.1 new-glibc  602 k
 nscd             x86_64 2.5-123.el5_11.1 new-glibc  178 k

Transaction Summary
====================================================================
Install       0 Package(s)
Upgrade       7 Package(s)

Total download size: 32 M
Is this ok [y/N]: y
Downloading Packages:
-------------------------------------------------------------------
Total                                                                                              14 GB/s |  32 MB     00:00    
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
  Updating       : glibc-common                                1/14
  Updating       : glibc                                       2/14
  Updating       : nscd                                        3/14
  Updating       : glibc-headers                               4/14
  Updating       : glibc-devel                                 5/14
  Updating       : glibc                                       6/14
  Updating       : glibc-devel                                 7/14
  Cleanup        : glibc-headers                               8/14
  Cleanup        : glibc-common                                9/14
  Cleanup        : glibc                                      10/14
  Cleanup        : glibc                                      11/14
  Cleanup        : nscd                                       12/14
  Cleanup        : glibc-devel                                13/14
  Cleanup        : glibc-devel                                14/14
Installed products updated.

Updated:
glibc.i686 0:2.5-123.el5_11.1     
glibc.x86_64 0:2.5-123.el5_11.1                                

Dependency Updated:
glibc-common.x86_64  0:2.5-123.el5_11.1
glibc-devel.i386     0:2.5-123.el5_11.1     
glibc-devel.x86_64   0:2.5-123.el5_11.1     
glibc-headers.x86_64 0:2.5-123.el5_11.1     
nscd.x86_64          0:2.5-123.el5_11.1         

Complete!

6). 업데이트 패키지 버전 확인
#rpm -qa | grep glibc
glibc-devel-2.5-123.el5_11.1
compat-glibc-headers-2.3.4-2.26
compat-glibc-2.3.4-2.26
compat-glibc-2.3.4-2.26
glibc-2.5-123.el5_11.1
glibc-2.5-123.el5_11.1
glibc-devel-2.5-123.el5_11.1
glibc-headers-2.5-123.el5_11.1
glibc-common-2.5-123.el5_11.1

2. YUM 명령어를 이용하여 패키지 다운그레이드 하기

1). 기존 RPM 버전 확인 및 백업
#rpm -qa | grep glibc
glibc-devel-2.5-123.el5_11.1
compat-glibc-headers-2.3.4-2.26
compat-glibc-2.3.4-2.26
compat-glibc-2.3.4-2.26
glibc-2.5-123.el5_11.1
glibc-2.5-123.el5_11.1
glibc-devel-2.5-123.el5_11.1
glibc-headers-2.5-123.el5_11.1
glibc-common-2.5-123.el5_11.1

2). yum downgrade 명령어로 다운그레이드 진행
# yum downgrade glibc glibc-devel glibc-headers glibc-common nscd
Loaded plugins: katello, product-id, security, subscription-manager
Updating certificate-based repositories.
Repository 'new-glibc' is missing name in configuration, using id
Unable to read consumer identity
Setting up Downgrade Process
No Match for available package: nscd-2.5-81.x86_64
Resolving Dependencies
--> Running transaction check
---> Package glibc.i686 0:2.5-81 set to be updated
---> Package glibc.x86_64 0:2.5-81 set to be updated
---> Package glibc.i686 0:2.5-123.el5_11.1 set to be erased
---> Package glibc.x86_64 0:2.5-123.el5_11.1 set to be erased
---> Package glibc-common.x86_64 0:2.5-81 set to be updated
---> Package glibc-common.x86_64 0:2.5-123.el5_11.1 set to be erased
---> Package glibc-devel.i386 0:2.5-81 set to be updated
---> Package glibc-devel.x86_64 0:2.5-81 set to be updated
---> Package glibc-devel.i386 0:2.5-123.el5_11.1 set to be erased
---> Package glibc-devel.x86_64 0:2.5-123.el5_11.1 set to be erased
---> Package glibc-headers.x86_64 0:2.5-81 set to be updated
---> Package glibc-headers.x86_64 0:2.5-123.el5_11.1 set to be erased
--> Finished Dependency Resolution

Dependencies Resolved

===========================================
 Package            Arch       Version  Repository       Size
===========================================
Downgrading:
 glibc                i686        2.5-81   rhel-DVD      5.3 M
 glibc                x86_64    2.5-81   rhel-DVD      4.8 M
 glibc-common  x86_64    2.5-81   rhel-DVD      16 M
 glibc-devel       i386        2.5-81   rhel-DVD     2.0 M
 glibc-devel       x86_64    2.5-81   rhel-DVD     2.4 M
 glibc-headers    x86_64    2.5-81   rhel-DVD     596 k

Transaction Summary
===========================================
Remove        0 Package(s)
Reinstall     0 Package(s)
Downgrade     6 Package(s)

Total download size: 32 M
Is this ok [y/N]: y
Downloading Packages:
-------------------------------------------
Total                                        10 GB/s |  32 MB     00:00    
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing     : glibc-common                          1/12
  Installing     :                                       2/12
  Installing     : glibc-headers                         3/12
  Installing     : glibc-devel                           4/12
  Installing     : glibc                                 5/12
  Installing     : glibc-devel                           6/12
  Cleanup        : glibc-headers                         7/12
  Cleanup        : glibc-common                          8/12
  Cleanup        : glibc                                 9/12
  Cleanup        : glibc                                10/12
  Cleanup        : glibc-devel                          11/12
  Cleanup        : glibc-devel                          12/12
Installed products updated.

Removed:
  glibc.i686 0:2.5-123.el5_11.1          
  glibc.x86_64 0:2.5-123.el5_11.1           
  glibc-common.x86_64 0:2.5-123.el5_11.1     
  glibc-devel.i386 0:2.5-123.el5_11.1     
  glibc-devel.x86_64 0:2.5-123.el5_11.1     
  glibc-headers.x86_64 0:2.5-123.el5_11.1    

Installed:
  glibc.i686 0:2.5-81            
  glibc.x86_64 0:2.5-81            
  glibc-common.x86_64 0:2.5-81    
  glibc-devel.i386 0:2.5-81   
  glibc-devel.x86_64 0:2.5-81    
  glibc-headers.x86_64 0:2.5-81   

Complete!

3). 다운그레이드된 패키지 버전 확인
# rpm -qa | grep glibc
glibc-2.5-81
glibc-2.5-81
compat-glibc-headers-2.3.4-2.26
compat-glibc-2.3.4-2.26
compat-glibc-2.3.4-2.26
glibc-headers-2.5-81
glibc-devel-2.5-81
glibc-common-2.5-81
glibc-devel-2.5-81