FÖREBYGGA Downtime! Seamless Site / Blog Move - VPS Bible # 19

Migrera din webbplats eller blogg till en ny server med minimala problem eller otillgänglighet. Denna guide kliver ut ur en bevisad omlokalisering förfarande.

När jag flyttade min sida från min delade värd till min skinande nya VPS på Linode var detta ett problem för mig, särskilt som jag hade ett ständigt växande databas. Avkokning nätet hittade jag några knapphändiga instruktioner men ingenting grundlig, och ingen handledningar som gav mig förtroende. Så jag frågade på Linode forum, och den process som stakats ut nedan är en resumé av de råd som ges av typ folk där, tillsammans med mina egna erfarenheter.

.. Så, för denna process, kan du tacka Linode Forumanvändare btmorex, Lykaions, kirbysdl och hybinet.

Denna handledning avser en delad till VPS flytta, men kan tillämpas på alla server-till-server flytta.

Först upp, Self-Service

DON'T TELL YOUR OLD värd som du tänker flytta.

Registrera dig med en ny Web Host

Om du inte vet vilken typ av värd du behöver, VPS Bibeln Del 1: VPS (Virtual Private Server) vs Delad vs Dedicated hjälper dig att välja.

Om du ska opåverkad VPS rutten, läs denna bibel från topp till tå. Om du är oövervakade, för resten av den här guiden kommer jag antar att du har byggt din box. För delade lyckades VPS eller dedikerad, är din låda byggd i alla fall, så låt oss hoppa på.

Skapa DNS Records

I grunden är dessa berätta en server för att leta efter en domän.

Om din nya värden inte tillåter DNS-konfiguration, det är ganska dålig. Else du med en gemensam server, då du får vad du betalar för. För dem som kan utföra DNS-administration ..

Lägg till DNS-poster i kontrollpanelen så, till exempel med Linode eller Slicehost det är gjort i DNS Manager. Du kan referera till VPS Bibeln Del 9: Lägg till en domän Zone till din VPS för detaljer och en förklarande video. Ge allt en riktigt låg TTL (time to live) värde. Om du har några MX eller andra DNS-poster hos din nuvarande värd, replikerar dessa.

Oroa dig inte, går inte att din domän lösa det nya värdlandets förtid, men inte förbereda den för migration.

Twin Gamla webbplats eller blogg

Duplicate din webbplats eller blogg filstrukturen på den nya servern, skapa & länk några databaser och importera dina data inom.

Ändra Hosts File till Test webbplats eller blogg

Top trick, det här. Du kan ändra en fil på din dator för att omdirigera URI till den nya servern, bara för dig. Detta har effekt inte den ursprungliga platsen, eller dess allmän trafik (om de inte har ändrat sin värd filer också!)

Windows

Gå till min c:> Windows> system32> Drivers> etc och öppna hosts med en texteditor.

Linux

Goto etc> och öppna värdar med en textredigerare.

Mac

Jag vet inte. Please Lemme know!

Du vet att det är rätt fil, eftersom den kommer att få en post eller två gillar: --

127.0.0.1	localhost

... and that is the format you want for the new lines you have to add to the file. So add something like:-

12.34.56.78  domain.com
12.34.56.78  www.domain.com

... swapping the IP for your new IP, and the domain for yours.

Upon saving the file, when you surf to domain.com, instead of taking you to your old server, it will take you to the new one, and you can fully test your site's functionality.

(I told you that was top )

NOW TEST YOUR NEW SITE'S FUNCTIONALITY.

But don't administer the wrong site: after testing, don't forget to delete the new hosts entry, else comment it out with a # at the beginning of the line. And restart your web browser.

Resolve Email

Move your email accounts from your current host.

If you want a simple, spam-free solution with no web server resource cost (ie no personal mail server), check out the VPS Bible Part 18: Google Apps for Domain-Specific Email .

Test your email.

Create A or AAAA Records

This is the key to a seamless move, which is particularly important if, for example, you host a forum or receive a lot of blog comments.

What we're going to do is to set up your new host to resolve the domain call to your old host. Basically, this eliminates the possibility of writing to more than one database while, for example, the nameservers propagate or Google's global servers refresh your new domain details.

In the new server's DNS settings, add two A/AAAA records using these guidelines:-

When you save your options, you may find one of the hostname fields is blank. That's normal.

Point Domain to Nameservers

Goto your domain registrar account and look for the Nameserver option. Renew the data.

For example, with Linode, bless, change to ns1.linode.com, ns2.linode.com, ns3.linode.com and ns4.linode.com. You'll find your new web host's nameserver details easily enough.

Now we are awaiting full propagation, at all server points around the world. I have no idea how long that takes, but about 72 hours is generally reckoned, so allow for 4-5 days to be safe.

MOVING DAY!

Go back to those A Records we created, replacing the old host IP to your new host IP. Set the TTL to the shortest possible 'time to live'. But before you click OK ..

Take a final backup of your old database and import the data into your new one.

.. And now you can click OK on those new A records.

While your A record changes will update the new host nameservers within minutes, it takes up to 72 hours for full web-wide propagation. You may find new data records in the old database, so you'll have to export and import those strays.

Note: At Linode, updated DNS records take effect every 15 minutes. So if you edit an A record at 2:32, it'll take until 2:45, plus the time period specified in the TTL, for the update to be visible to the world. Careful timing will give you the least downtime.

Final Checks

If you completed the previous testing properly, there should be no surprises. Then again ..

After the time period specified in the TTL, check your site to ensure everything works. Because your local nameservers may not yet have resolved with th Du vet att det är rätt fil, eftersom den kommer att få en post eller två gillar: --

127.0.0.1	localhost

... and that is the format you want for the new lines you have to add to the file. So add something like:-

12.34.56.78  domain.com
12.34.56.78  www.domain.com

... swapping the IP for your new IP, and the domain for yours.

Upon saving the file, when you surf to domain.com, instead of taking you to your old server, it will take you to the new one, and you can fully test your site's functionality.

(I told you that was top )

NOW TEST YOUR NEW SITE'S FUNCTIONALITY.

But don't administer the wrong site: after testing, don't forget to delete the new hosts entry, else comment it out with a # at the beginning of the line. And restart your web browser.

Resolve Email

Move your email accounts from your current host.

If you want a simple, spam-free solution with no web server resource cost (ie no personal mail server), check out the VPS Bible Part 18: Google Apps for Domain-Specific Email .

Test your email.

Create A or AAAA Records

This is the key to a seamless move, which is particularly important if, for example, you host a forum or receive a lot of blog comments.

What we're going to do is to set up your new host to resolve the domain call to your old host. Basically, this eliminates the possibility of writing to more than one database while, for example, the nameservers propagate or Google's global servers refresh your new domain details.

In the new server's DNS settings, add two A/AAAA records using these guidelines:-

When you save your options, you may find one of the hostname fields is blank. That's normal.

Point Domain to Nameservers

Goto your domain registrar account and look for the Nameserver option. Renew the data.

For example, with Linode, bless, change to ns1.linode.com, ns2.linode.com, ns3.linode.com and ns4.linode.com. You'll find your new web host's nameserver details easily enough.

Now we are awaiting full propagation, at all server points around the world. I have no idea how long that takes, but about 72 hours is generally reckoned, so allow for 4-5 days to be safe.

MOVING DAY!

Go back to those A Records we created, replacing the old host IP to your new host IP. Set the TTL to the shortest possible 'time to live'. But before you click OK ..

Take a final backup of your old database and import the data into your new one.

.. And now you can click OK on those new A records.

While your A record changes will update the new host nameservers within minutes, it takes up to 72 hours for full web-wide propagation. You may find new data records in the old database, so you'll have to export and import those strays.

Note: At Linode, updated DNS records take effect every 15 minutes. So if you edit an A record at 2:32, it'll take until 2:45, plus the time period specified in the TTL, for the update to be visible to the world. Careful timing will give you the least downtime.

Final Checks

If you completed the previous testing properly, there should be no surprises. Then again ..

After the time period specified in the TTL, check your site to ensure everything works. Because your local nameservers may not yet have resolved with the new A record data, and so that you can be sure you're looking at the new, not the old, web application, use the host file trick.

Shed Shared, Viva Virtual!

Whatever kind of web host you've moved to, you can cancel the old host 4-5 days after moving day. Your breathing will gradually shallow out. Take tea!

Virtually Done

This series is pretty much complete, and I'm definitely gonna be spending more time down the pub.

However, as a round-up, VPS Bible Part 20: Blogroll, Links, Credits, Resources will list some of the best resources on the web for anything Linux or VPS. Plus it's a bit of a thank you to all those whose advice has helped me to go from VPS newbie, a few months ago to, well, senior newbie. Hey, you be the judge, but I sure ain't a sysmin.

By way of a follow up, and as promised in VPS Bible Part 17: Nginx Control Panel Workarounds , I'll be publishing some appendix guides too, showing you how to administer your VPS without relying on bloatware like cPanel.

Here's the you-know-what ...