To add on to Rick's answer. I don't know what process you
have been through already James but if this is the beginning of the process
you may want to change your direction a little.
You need to approach your business and find out what kind
of recovery time they want and then what kind of a recovery time they need [1].
Then start looking at what you can get to with various exchange designs. You
will have to know how fast do they need "current" email capability, e.g. send
message to fred right now. Also you will need to know how fast they need
historic info [2]. This will vary greatly for companies. Some companies need
current all of the time but can lose historic for hours or days. Some need
historic every hour but can go without current for several hours. Some need both
right away and of course some can go a day without either. Finally you could
have a company where some groups don't care much at all and some use email as
their lifeblood, this seems to be the norm and defeats people who want a
homogenious design unless overall they can make recovery very very quick. It
completely depends on the company and the groups and functions within the
company and how much money is available.
Once you know what kind of recovery is required, you can
look at the different mechanisms required to achieve it and report back ball
park figures to the business. At which point you will probably get redefinitions
of what is wanted and needed. I haven't met many business people willing to pay
for true DR the way they want it. :o)
All that to say is that your SLA/SLO or whatever you want
to call it will require a specific design which could have
serious influence over how you backup/restore/recover. You could easily
find that restoring the data from tape isn't that important so could get a
solution that takes 2 days as long as people can send emails in real time. You
may find you need a hot backup 25 miles from the "real" exchange
server.
You don't want to come up with a design and then have the
business say, well that isn't what we need and then redesign.
joe
[1]
Want and need will be different values because no one ever really seems to want
only what they need but they all have an issue differentiating between want and
need.
[2]
Historic defined as everything prior to the loss of the
system.
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Rick Boza
Sent: Sunday, October 24, 2004 9:24 AM
To: ActiveDir List
Subject: Re: [ActiveDir] Exchange OT:
Do you mean ‘how long does it take to copy all mailboxes from one server to another?’ If so that’s going to depend on many factors, not the least of which is connectivity between the boxes.
If you mean how long to restore from tape, you’re typically looking at about 7.5 Gigs per hour, plus an hour to decide you actually need to do a restore (in my experience folks troubleshoot and debate the need to restore for at least one hour before the restore is kicked off). So a 40 GB PRIV would take roughly 6 hours plus one for the lead in.
This is assuming a pretty conventional recovery plan, meaning regular full backups and whatnot. There are other ways to approach backup and restore depending on how big your budget is!
On 10/24/04 9:11 AM, "Blair, James" <[EMAIL PROTECTED]> wrote:
To to the amazinly diverse audience out there: I am putting together a disaster recovery procedure and was wondering how long it would take to restore mailboxes directly from the database to an aleternate e-mail server. Is there any baselines out there or does anyone have any personal experience? Lets say database is 40GB...
James
