Windows Server

Fab · Guest

Hi there,

I have a Dfs setup where my Dfs root is hosted on a W2K server, and the
Dfs links map to shares on W2K and W2K3 servers (a mixed environment).
More specifically,

\\server_A\I\folder_A replicates to \\server_C\I\folder_A
\\server_B\I\folder_B replicates to \\server_D\I\folder_B
\\server_C\J\folder_C replicates to \\server_D\J\folder_C

Servers A and B run on W2K - SP4 and servers C & D run on W2K3. While
the file replication service on A and B run just fine, FRS on servers C
& D use up a lot of CPU time. In fact, it gets so bad that I cannot
login to either machine, and will have to reboot the servers. I should
mention that servers C & D hosts about 80 Dfs links and there has been
a lot of replication happening in the past 10 months. The size of
ntfrs.jdb on server C is about 13 GB, and on server D it is about 14
GB. Does anyone know if the size of FRS database contributes to the
high CPU usage of FRS on these two servers? If not, what else can cause
this very high CPU usage? I checked the FRS eventlog on both machines,
and there is no unusaul event other than an occasional event complaing
that FRS stopped without cleaning up. If I know for sure that the big
size of ntfrs.jdb on these servers are the main source of high CPU
usage, then perhaps I can reduce the size by doing a D2. I really have
no idea what else can drive FRS CPU usage so high. Any help is highly
appreciated.

Thanks,

Fab

Paul Williams [MVP] · Guest

You ask a good question. Now I'm no expert at DFS/ FRS. I just help out
here, because a lot of people get SYSVOL problems. I've not really run FRS
in a big way in production - only in small environments for specific tasks
(although this will change when I start rolling out R2 to customers).
However I would say that a large JDB file such as yours will cause high CPU
usage. Replication is reading and writing to that file a lot, and the
bigger it is the more it needs to be read into memory and paged. It sounds
like the transactions aren't being purged. I would try rebooting. If that
doesn't work, I would ring Microsoft and see if they can help out.

I'd be very interested to see a follow up if.

Thanks!

--
Paul Williams
Microsoft MVP - Windows Server - Directory Services
http://www.msresource.net | http://forums.msresource.net

Fab · Guest

Thanks Paul. We tried rebooting, and it seems to work at first, but
after a while ntfrs CPU usage goes to nearly 100%.

I am thinking to run esentutl /d ntfrs.jdb to see if defragmentation of
jdb will help. The other thing that I am thinking to do is a D2 for
specific replica, but I can't seem to remember if it's possible and if
so, what registry key needs to be changed. Any thoughts?

Fab

Paul Williams [MVP] · Guest

A defrag was going to be my next suggestion. How did this go? Or did you
just do a D2?

--
Paul Williams
Microsoft MVP - Windows Server - Directory Services
http://www.msresource.net | http://forums.msresource.net

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