[CentOS] Advice on upgrading packages

Hi all,
Regarding packages updates using yum, all this time I only upgrade packages 
that I think is important, but also at the same time is having little risk of 
breaking my installation. Such as httpd, ssh, etc.

But there are many packages that waits to be updated such as lvm, mdadm, etc. 
I'm worried that it will break my installation (web and mail server). Like 
the saying "if it ain't broken, don't fix it".

Is there any pitfall that I should avoid of when upgrading packages using yum? 
Or is it completely save to let yum update the machine automatically?
Thank you very much,
-- 
Fajar Priyanto | Reg'd Linux User #327841 | Linux tutorial 
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