Hey I have a question: How can you calculate how much diskspace is needed to let the exchange server 2003 run whitout problems Greets

How much disk space do you have? Multiple that by 10. Seriously, here are some suggestions, but this depends on your own environment. For a server that will support 500 mailboxes, here are some ideas. For your OS/binaries disk, plan for at least 30GB For the transaction log disk, plan for 20 - 30GB (I always want to be able to hold a weeks worth of transaction logs For the Database disk, take the maximum size of each mailbox (let's say the maximum size is 500MB), multiply that by the number of mailboxes, then add 20%. That should give you your maximum database size. That would be 300GB. Make your database disk 600GB. I try to estimate disk space for the absolute worst possible case. It is usually cheaper to get it ahead of time and have some room to grow comfortably than it is to always be cleaning up your disks or having to buy more disk space after the server is online for only a year. My opinion, though. Take it for what it is worth.

If you want to be able to perform offline defrags you need to have at least 120% free space more then the size of the Exchange databases. Transaction logs should be removed post backup (most backup software will do this for you automatically). We run nightly backups so we do not keep more then one day's worth. I run a HUGE organization (one of my 24 Storage Groups tops off at 486GB, Average Storage Group size = 240GB) and none of my Transaction Log partitions is over 9GBs in size. The only time this gives me problems is when I move large mailboxes. Message Tracking Logs - I like to track everything! and include "subject". This can take up a lot of space. Anticipate a min. of 10GB for this. IIS Logs - If you have OWA setup these logs can grow. At the very least you want to move them from their default location (C:\WINDOWS\system32\LogFiles\W3SVC1) so you don't inadvertently crash your server. Event Logs - Bare in mind that if you undersize your "system" partition then the .evt logs can be an issue. They can be moved to a different location. The key thing for me is to protect my "systems" partition. I don't want anything running crazy and filling up that drive or there might be no recovering from it. How big is your store right now? Any sense to how much daily emailing is going on? I suggest creating a weekly tracking report to gather this info. Monitor all drives on your mail server for growth.

Oh yeah, and don't forget recovery. Not sure what you restore strategy will be but if you plan to use the Recovery Storage Group you will end up restoring the entire database to extract email from. Anticipate free space need at the same size as your biggest database and then some for growth.

There are very good suggestions above. I just wanted to throw in that you should think about the Structure of the space as well as the size. Be sure to plan on Seperating the OS, Logs, and DBs at a minimum on different arrays. Here is a couple of points taken from this Guide: http://technet.microsoft.com/en-us/library/bb125079.aspx There are tons of articles on this subject. Disk subsystem bottlenecks cause more performance problems than server-side CPU or RAM deficiencies, and a poorly designed disk subsystem can leave your organization vulnerable to hardware malfunctions. Specifically, your disk subsystem is performing poorly if it is experiencing: Average read and write latencies over 20ms. Latency spikes over 50ms that last for more than a few seconds. High disk latency is synonymous with slow performance. To reduce costly disk latency issues, at a minimum, you should: Invest in high performance disks and spindlesIt is better to have smaller capacity disks that utilize each spindle's performance than to use fewer spindles with large capacity. Fast storage with a sufficient amount of spindles is one of the most important investments you can make in your messaging infrastructure. Consider performance before capacityRelying on capacity as the primary metric for storage sizing often results in poor performance for your disk subsystem. For example, most administrators who select a RAID-5 solution do so to maximize storage usage. However, in many cases, properly sizing the performance of your spindles requires you to use more physical disks for RAID-5 than RAID-1+0. Align your disksUse Diskpart to verify that your disk tracks are sector-aligned. By using Diskpart to create aligned partitions (as compared with non-aligned partitions that are created with Disk Manager), you can increase disk performance by 20 percent. For detailed steps, see How to Align Exchange I/O with Storage Track Boundaries. Note that Diskpart can only be used with basic disks. Diskpart cannot be used with dynamic disks. Diskpart is part of the Windows Server 2003 Service Pack 1 Support Tools. Diskpart supersedes the functionality found in Diskpar, a Windows 2000 Server Resource Kit tool.