Hi All, We are currently planning a 2010 inplementation and I have been really struggling to find out sizing requirements for CAS and hub transport server roles. I have been able to find a good ammount of information based on CPU and memory requirements but none for disk. Are there any articles you can point me to or any general rules of thumb? Setup is 2 sites, one as a cold DR site and the other as a live site. Both sites will have one mailbox server and one multi-role CAS/HUB server each. Thanks in advance.

The CAS doesn't "need" disk space over and above the OS and app. The HT needs sufficient disk space to hold and process messages. You can't buy disks small enough to present you with a problem these days. "Rich129089" wrote in message news:dc2c7f42-45de-4654-9634-489eb106800e... Hi All, We are currently planning a 2010 inplementation and I have been really struggling to find out sizing requirements for CAS and hub transport server roles. I have been able to find a good ammount of information based on CPU and memory requirements but none for disk. Are there any articles you can point me to or any general rules of thumb? Setup is 2 sites, one as a cold DR site and the other as a live site. Both sites will have one mailbox server and one multi-role CAS/HUB server each. Thanks in advance. Mark Arnold, Exchange MVP.

Hi, From Exchange 2010 requirement, we can find the following: • At least 1.2 GB on the drive on which you install Exchange • An additional 500 MB of available disk space for each Unified Messaging (UM) language pack that you plan to install • 200 MB of available disk space on the system drive • A hard disk that stores the message queue database on an Edge Transport server or Hub Transport server with at least 500 MB of free space Exchange 2010 System Requirements http://technet.microsoft.com/en-us/library/aa996719.aspx Regards, Xiu

Thanks Guys, much appreciated. That would be why I didnt find any real information because there isn't a huge amount of explanation needed!

The CAS doesn't "need" disk space over and above the OS and app. The HT needs sufficient disk space to hold and process messages. You can't buy disks small enough to present you with a problem these days. "Rich129089" wrote in message news:dc2c7f42-45de-4654-9634-489eb106800e... Hi All, We are currently planning a 2010 inplementation and I have been really struggling to find out sizing requirements for CAS and hub transport server roles. I have been able to find a good ammount of information based on CPU and memory requirements but none for disk. Are there any articles you can point me to or any general rules of thumb? Setup is 2 sites, one as a cold DR site and the other as a live site. Both sites will have one mailbox server and one multi-role CAS/HUB server each. Thanks in advance. Mark Arnold, Exchange MVP. Mark- I'd disagree a bit about the CAS servers just in the fact that CAS generates log files which you'll want to retain at least for a little while and they take a decent pile of space depending on how long you plan to retain them for and how busy your site is. With HT servers if these are really quite busy, think about 4 drives RAID10 for the mail queues.Active Directory, 4th Edition - www.briandesmond.com/ad4/

We have about 400 mailboxes, so whilst we aren't huge the mail flow from those users is quite high. I guess this could be a scenario where over sizing in terms of space is a good idea. Are there any calculations with regards to amount of mail flow and the sizes of logs generated?

You're right to an extent. My point was illustrative. Smallest FC drive? 450GB. That's a lot of log. Smallest SATA disk? 1TB. An awful lot of log. So yes, CAS needs space for logs but you will be hard pushed to fill it up unless you fail to configure appropriately........... and that's an entirely different question. "Brian Desmond -MVP-" wrote in message news:5a52caa5-f978-4583-a7c9-f36c533f34fd... The CAS doesn't "need" disk space over and above the OS and app. The HT needs sufficient disk space to hold and process messages. You can't buy disks small enough to present you with a problem these days. "Rich129089" wrote in message news:dc2c7f42-45de-4654-9634-489eb106800e... Hi All, We are currently planning a 2010 inplementation and I have been really struggling to find out sizing requirements for CAS and hub transport server roles. I have been able to find a good ammount of information based on CPU and memory requirements but none for disk. Are there any articles you can point me to or any general rules of thumb? Setup is 2 sites, one as a cold DR site and the other as a live site. Both sites will have one mailbox server and one multi-role CAS/HUB server each. Thanks in advance. Mark Arnold, Exchange MVP. Mark- I'd disagree a bit about the CAS servers just in the fact that CAS generates log files which you'll want to retain at least for a little while and they take a decent pile of space depending on how long you plan to retain them for and how busy your site is. With HT servers if these are really quite busy, think about 4 drives RAID10 for the mail queues. Active Directory, 4th Edition - www.briandesmond.com/ad4/Mark Arnold, Exchange MVP.

We have about 400 mailboxes, so whilst we aren't huge the mail flow from those users is quite high. I guess this could be a scenario where over sizing in terms of space is a good idea. Are there any calculations with regards to amount of mail flow and the sizes of logs generated? I wouldn't even worry about it for something that scale. As long as you're not going to try and allocate teh minimum size possible virtual disk or boot from SAN with tiny LUNs you're going to be fine. If you want, put the OS/Exchange on a 40-60GB partition and then move the queue database and log paths to a second partition.Active Directory, 4th Edition - www.briandesmond.com/ad4/