Determining Maximum Volume Size

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

Volume sizes often vary, but it is important to set a maximum volume size. NTFS supports volumes up to 256 TB minus 64 KB (232 clusters minus 1 cluster), but it is recommended that you take the following factors into account when you determine the size of volumes in your file servers.

Backup and restoration times

Sizing your volumes to be the same size or smaller than your backup solution’s capacity is a good guideline but not an absolute rule. For example, some organizations might back up files on a per-folder basis rather than on a per-volume basis. In this case, the organization would make sure that the size of each folder is smaller than the backup solution. This method, however, requires more backups — one for every folder. In the event that you must restore the data, this method also requires more restorations to restore all the folders on the volume, increasing the overall complexity and length of the process. Because emergency restorations are often done in a hurry and under pressure, let restoration time and simplicity be your guide for sizing volumes.

Chkdsk times

Although file system errors are rare on NTFS volumes, you need to consider the time required to run Chkdsk to repair any errors that occur. Chkdsk times are determined by the number of files on the volume and by the number of files in the largest folder. Chkdsk performance has improved significantly since Windows NT 4.0 and Windows 2000. As a result, downtime due to Chkdsk should be minimal. However, it is important to avoid having volumes that contain so many files that Chkdsk requires longer to complete than the amount of downtime your users can tolerate.

To determine how long Chkdsk takes to complete, run Chkdsk on a test server with a similar number of files as those stored on a typical file server volume. Based on these results, you can limit the number of files to be stored on a volume so that Chkdsk can complete within the acceptable time limit.

Important

• Windows Server 2003 provides some Chkdsk parameters that shorten the time required to run Chkdsk. However, if the volume contains file system errors, you must consider the volume at risk until you are able to run a full Chkdsk. For more information about running Chkdsk, see "Chkdsk" in Help and Support Center for Windows Server 2003.

If you need to store a large number of files on a file server and are concerned about Chkdsk times, you can distribute the files on separate volumes on the file server. If, however, you need those files to appear as though they are on a single volume, you can use mounted drives. When you create a mounted drive, you mount one local volume at any empty folder on another local NTFS volume. For example, you can create a folder called Data on volume E and then mount volume F to that folder. When you open the Data folder, the contents of volume F are displayed.

Mounted drives are also useful when you want to add more storage to an existing volume without having to extend the volume. For more information about mounted drives, including information on creating mounted drives on clustered file servers, see "Using NTFS mounted drives" in Help and Support Center for Windows Server 2003.