[CentOS] Updates offered annoyance

Wed Aug 25 14:03:45 UTC 2010
Todd Denniston <Todd.Denniston at tsb.cranrdte.navy.mil>

Les Mikesell wrote, On 08/25/2010 08:29 AM:
> On 8/25/10 7:14 AM, Aleksandar Stoisavljevic wrote:
>> Hi all,
>>
>> I downloaded latest CentOS 5.5 DVD i386 image from one of FTP's in a list.
>>
>> I've burned that image to DVD and created new DVD to use for fresh installations.
>> Now when I install fresh CentOS 5.5 (in VM) I am getting info that there are 50
>> packages updates.
>>
>> This is ok when I have good internet speed (@work) but when I am home, this
>> update takes a lot of time.
>>
>> I guess I can skip updates but I wasn't experiencing such annoyance with CentOS
>> 5.4. My gues is that when
>> CentOS 5.4 was finalized there is no updates to that DVD.
>>
>> Is there any suggestions ?
> 
> Updates are a good thing - they mean bugs and security issues are being fixed. 
> If you like to baby-sit the update process, try it this way:
> yum install yum-downloadonly
> then you can:
> yum -y --downloadonly update
> and go away (or sleep) while the update rpms download. If this step doesn't 
> complete you can restart it as many times as necessary and it won't actually 
> install anything.  After the downloads have completed, you can do
> yum -y update
> to install them and it will run quickly.
> 

And if you are maintaining more than one machine at home, you need to realize that you don't need to
waste the time twice to update the same thing on two machines.  Assuming your home machines are
networked together.

change /etc/yum.conf
from
keepcache=0
to
keepcache=1

and then after updating the first machine, you can update the second by
scp -pr root at machine1:/var/cache/yum/ \
   root at machine2:/var/cache/yum/
or
rsync --relative root at machine1:/var/cache/yum/./ \
   root at machine2:/var/cache/yum/
(I do suggest reading the man pages on both commands and see if there are other things you want to
add, such as -hvaK --delete-after --hard-links --sparse on rsync.)

Then do the yum update on the second, and it will only pull in updates that are unique to the second
system. Of course if the second system pulls in new updates and you have 3, 4 ... N machines to
update,  you'll want to pull from the systems with more stuff to do the updates on later systems.

Another option would be to see if your employer would be OK with you occasionally making DVD or USB
copies of the CentOS & EPEL mirrors maintained at work to take home, assuming your employer
maintains a mirror set locally.

current Centos updates
2.0G    updates/i386
2.1G    updates/x86_64
(of course this is without trimming the 450MB that repomanage --nocheck -k1 -o i386/ might tell you
about if the mirror is maintained with out rsync)
current epel
3.7G    i386
4.2G    x86_64

-- 
Todd Denniston
Crane Division, Naval Surface Warfare Center (NSWC Crane)
Harnessing the Power of Technology for the Warfighter