Rather than just spread my war stories about Exchange I will offer some
useful advice for anyone considering using it. I suggest you read these
points and articles and then try to backup and restore a non-live server
in a test environment before making a decision (a 120-day eval of
exchange is available).
Most people do not realize how complex and unreliable Exchange backup
and restore is.
- All data is stored in JET databases (MS ACCESS)
- Each databases is split into two parts (*.EDB and *.STM)
- Databases can be corrupt but still *seem* to work
- Databases are used for several users at the same time
- Repairs often require databases stores to be dis-mounted
- Corrupt databases will often stop information stores mounting
- Backup agents often do not work as advertised and can be risky
- Flat-file backups of a dismounted store are the most reliable
See the following for more information:
Offline Backup and Restoration Procedures for Exchange
http://support.microsoft.com/kb/296788/
Corrupt information stores are your worst nightmare
- Your information store could have been corrupt for weeks before
crashing (your backups could be corrupt too)
- Everything is connected
- Information stores are tied to custom Active Directory attributes
- Information stores are tied to individual users (UID's)
- Information stores are tied to individual servers
- All of this has to be correct for stores to mount
- Just copying databases back will not always work
- A "consistency adjuster" may need to be used to "mask" big problems
- If your Exchange server "crashed" and cannot be started again to
properly "remove" it from active directory, you may not be able to add a
new exchange organization cleanly and may have to START AGAIN with a NEW
active directory (THIS IS COMPLETELY TRUE - THE MS ARTICLES ON THE
SUBJECT DO NOT WORK IN SOME INSTANCES)
For more information see:
How to recover the information store on Exchange 2000 Server or Exchange
Server 2003 in a single site
http://support.microsoft.com/kb/313184/
If you do decide to use Exchange (which I strongly advise against)
- Do not rely on live backups
- Use flat-file backups of databases by scheduling a job to dismont the
message stores and copy files to another disk, drive or server
- Copy your flat-file backups to another server with the Exchange
administration tools installed.
- Learn to use ESEUTIL on previously made flat-file backups (you will be
amazed how many messages get lost or have blank contents)
- Learn to use EXMERGE for "last-hope" disater recovery (or to move to a
better mail system at a later date)
- Invest in "Ontrack PowerControls" to repair mailboxes safely offline
- NEVER restore to live servers, export to PST, check PST, import PST
- Outlook 2003 PST files are not compatible with previous versions
- Applying exchange service packs can make previous backups un-useable
- If your exchange server is also a domain controller everything gets 3
times harder. Do not run exchange as a DC or GC, PDC or infrastructure
master.
- Note: You can't help running exchange as a DC, GC, PDC and
infrastructure master in Small Business versions of exchange or single
server sites.
- Before you finally make the move look at all of the broken parts of
Exchange using technet.com (make sure you specifically select exchange
as the product and only troubleshooting as the category). Every category
I searched showed exactly 100 issues, then I realised that the search
only returns 100 issues (How many exchange issues are there? at least a
100 store problems, at least 100 database problems, at least 100 mailbox
problems etc..)
- Each of the tools used to "fix" exchange have at least another 100
issues themselves.
LOOK BEFORE YOU LEAP
Hope this helps someone
Jason
P.S did I mention that Scalix is a better alternative - www.scalix.com
Since replacing Exchange with Scalix a four man team has been able to
get back to some "real" IT work which helped us reduce IT costs in a
multi-million dollar company by 75% this year, isn't that what IT
depts should be doing instead of trying to keep buggy software
together or just constantly handing out the protection money for new
versions.
Jason
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