This article describes the correct staging area space for
replica sets. The File Replication service (FRS) creates staging files to
replicate data among replica set members. It is important to allocate enough
staging area space. If you do not have enough staging area space, various
problems may occur.
The Staging folder stores modified files temporarily before
they are propagated to other replication partners. The FRS encapsulates the
data and attributes that are associated with a replicated file (or folder)
object in a staging file. The FRS needs enough staging area space on both
upstream and downstream computers to replicate files.
2000 Service Pack 2 (SP2) and later, when a staging file has been generated on
the originating computer, the FRS compresses the file. This saves space in the
staging file and causes less data to be replicated between members. It also
makes sure that the file data can be supplied to partners no matter what file
activity might prevent access to the original file.
The staging area
size limits in Windows 2000 and Microsoft Windows Server 2003 are:
660 megabytes (MB)
For additional information, click the following article
numbers to view the articles in the Microsoft Knowledge Base:
Description of FRS Entries in the Registry
File Replication Service Stops Responding When Staging Area Is Full
If you are using Windows 2000 SP2 or earlier, note
that the FRS stops replicating if the staging area runs out of free space. If a
replica set member goes offline for an extended time, replication is not
blocked on an upstream member because the staging area is filled. Therefore, it
is a good idea to use a generous estimate for the staging area size.
Windows 2000 Service Pack 3 (SP3) and later uses an updated
staging-file-management algorithm. With the updated algorithm, if the FRS tries
to allocate space for a staging file but is not successful (because there is
not enough space or because the space in use has reached 90 percent of the
staging space limit), the FRS starts to delete staging files. Staged files are
deleted (in the order of the longest time since the last access) until the
space in use has dropped below 60 percent of the staging space limit.
Therefore, it is not as important to use as large an estimate for the staging
area size as it is for pre-SP3 systems, but it is still a good idea to do so.
This helps to prevent disk or CPU resources from being consumed by repeatedly
staging and deleting files.
Also, if you do not allocate enough
staging area space and the service starts the cleanup process when 90 percent
of the allocated space is in use, the system must generate those files again.
Replication may slow down or stop if many files or very large files are moved.
Staging Size Recommendations for the FRS on Windows 2000 SP3 and Later
This tables lists recommended staging area sizes.
Collapse this tableExpand this table
|Base staging space||660 MB||660 MB||660
|VVJOIN (When you are adding a new member)||MAX [660 MB
((128 largest files in the replica set) * number of downstream connections) *
1.2]||MAX [660 MB ((128 largest files in the replica set) * number of
downstream connections) * 1.2]||MAX [660 MB, ((128 largest files in the
replica set) * number of downstream connections) * 1.2]|
|Backlog (accounting for
schedules)||0||ADDITIONAL: (Maximum expected file change quantity
in a 7-day period) * 1.2||ADDITIONAL: (Additional space equal to full
expected replica set size) * 1.2|
|Configuration notes||None||Different drive for
the staging area||Different drive for the staging area|
recommended||Recommended||Recommended for configurations with the
best performance requirements|
Use the numbers in this table as base recommendations; adjusted
the values to fit your configuration.
Note that the FRS outbound log
processing has been changed in the Windows 2000 post-SP2 hotfix and in SP3 to
retain change orders even after they have been sent to all current downstream
partners. This change permits the FRS to synchronize with a new downstream
partner from the outbound log and to avoid a full IDTable scan. This change is
helpful in environments where the topology changes frequently. This change is
also helpful during a rollout when new members are coming online in a short
The default outlog change-order retention period is 7 days.
The space depends on your usage and environment. Because a cleanup routine has
been added that begins when 90 percent of the allocated staging space is
reached, a safety factor of 1.2 has been added in the equation.
For additional information about staging
area management, click the following article number to view the article in the
Microsoft Knowledge Base:
Improvements in the Post-S Release of Ntfrs.exe That Is Packaged with an Updated Ntfs.sys Driver