[NTLUG:Discuss] "Web site temporarily offline"

[Daniel Hauck]

David Simmons さんは書きました:
> 
>> I have my main web stuff on a VM and occasionally, I like to run
> backups
>> of the VM but it takes at least 20 minutes.  During that
> down time, I
>> would like to have another machine detect when the
> server is down and
>> assume the server's IP address so that it can
> say "Web site down for
>> maintenance.  Be back soon!"
>>
>> I imagine running a small VM that would run whatever
> processes needed.
>> Anyone know any magic tricks to
> accomplish this?
> 
> Welp....if you had a small 'other' hosting
> area...(maybe you got some with your DSL package?� maybe you can get
> some free Google / Yahoo area....just enough to create your 'We're Down -
> Be Back Soon' page.�� Then, before your backup script - change
> DNS to point to this new area (remember to reload/restart your DNS server)
> - do your backup - then change DNS back?
> 
> Albeit, not real magic
> - and you're up against the TTL (time to live) that might be an hour - so
> it might not really work as you'd like (although, I've seen the main DNS
> server's change very quickly) - it's an idea.
> 
> -dave

Yes, if down time was longer than 1 hour that might be an idea... but
here's something that is far more obvious and less megical.

Build another small VM and leave it not running until the backup process
starts which also pauses the machine to be backed up.  So:

1. pause VM to be backed up
2. start the "offline" VM
3. perform the backup
4. stop the "offline" VM
5. resume the VM backed up
6. done