From CentOS 5.5 to CentOS 6.0, downtime zero...
When my VPS is down, I loose money and it isn't really acceptable for me.
Since managing my VPS isn't my first activity due to I'm a mobile developer and I haven't too many times to spend on VPS I'll try to collect information on it on my spare time.
Now it's time to collect information on the big migration from CentOS 5.5 to 6.0…
Someone told me that a it's better to switch with a fresh install, some other else told me that a yum update should be enough since I used only RPM from official repository like RH and CentOS.
What do you think about this? Do you suggest a fresh install or a yum update?
If you suggest a fresh install how can I reduce the downtime as much as possible?
I thouth to buy a second linode, configure it when I have time, and than when it's ready and working ok, switch DNS to the CentOS 5.5 VPS to the new CentOS 6.0 VPS… But how to do this?
Suppose that I buy a second linode, configure it, than how do I need to switch from the old linode (and dismiss it) and pass my actual payed quota to the new one?
Thanks.
7 Replies
1) Make a new linode, install everything you need
2) Migrate websites over
then if you have databases that are updated regularly (i.e. by users not you).
3) Shutdown the site(s)
4) Dump databases
5) Load databases on the new server
6) Test everything works
7) Swap ips.
(if you don't have databases to worry about skip to 6)
First off, CentOS 6 is months and months away. RHEL 6 doesn't even have a firm release date (rumours say end of 2010 or early 2011) and CentOS is several months after that.
Second, what does CentOS 6 have that you need - not just want. With a 7 year support cycle per release, it's not like CentOS 5.x will go insecure or unsupported for a long time.
CentOS is not Ubuntu - they don't push crap out the door just to meet some mystical release cycle. They wait until it's stable - and a true UPDATE - before making a new release.
Besides, if downtime is unacceptable (i.e. it loses you money) then you really should have a duplicate server in a different datacenter anyways (update the backup server - make sure all is well - switch backup for primary - then repeat with the now out of date backup server).
@obs:
I've not used CentOS since version 4 so can't comment on your upgrade experience. But I can mention that if you have two linodes in the same datacentre you can swap their ips so I suggest something like the following.
1) Make a new linode, install everything you need
2) Migrate websites over
then if you have databases that are updated regularly (i.e. by users not you).
3) Shutdown the site(s)
4) Dump databases
5) Load databases on the new server
6) Test everything works
7) Swap ips.
(if you don't have databases to worry about skip to 6)
thanks for all replyes.
what you mean for swap ips?
this means change dns from old linode ip to new linode ip?
may I change also the payed quota? I mean…
usually I buy linode for one years, next times I think I will renew the service for two years, can I switch the money I payed for the old VPS to the new VPS by dismissing the old one?
Thanks.
Swap IPs
Move IP addresses between two of your Linodes that are in the same data center.
Select some IPs from this Linode with:
So your ip which already has DNS set up gets moved to the new server, so you don't get downtime due to DNS propagation.
As for paying, raise a support ticket and I'm sure linode will be able to help you out with whatever way you want to pay.
@obs:
To swap ips, go to your linode's dashboard, click the network tab and look for the bottom right panel, it says this:
Swap IPs
Move IP addresses between two of your Linodes that are in the same data center.
Select some IPs from this Linode with:
So your ip which already has DNS set up gets moved to the new server, so you don't get downtime due to DNS propagation.
As for paying, raise a support ticket and I'm sure linode will be able to help you out with whatever way you want to pay.
Wow, thanks!
