Help with TSM server being hammered by clients

        TSM Server 4.2.4.1 (Solaris)
        TSM Client 4.2.3 (Solaris)
        
        TSM DB 83GB (40% util)
        TSM Log 4.6GB 

        I am having a serious problem with 4 Solaris clients hammering the 
server during their backups.  Each client has a lot of file held on TSM, about 
4-5 million per node and growing, though not much data, only a couple of 
hundred GB's per node.  The server is very responsive when these clients are 
not backing up, all other backups run without lagging the server.  I have about 
120 nodes backing up to this server daily.
        What could be causing this performance problem?  Here is a show logpin 
during last nights backup:

tsm: I02SV1000>show logpin
Dirty page Lsn=4675033.188.3116, Last DB backup Lsn=4677956.167.3489, 
Transaction table
Lsn=4677883.231.3853, Running DB backup Lsn=0.0.0, Log truncation 
Lsn=4675033.188.3116 
Lsn=4675033.188.3116, Owner=DB, Length=128
Type=Update, Flags=C2, Action=ExtDelete, Page=6110475, Tsn=0:180594521, 
PrevLsn=4675033.180.2739,
UndoNextLsn=0.0.0, UpdtLsn=4675033.176.827 ===> ObjName=AF.Bitfiles, Index=12, 
RootAddr=29,
PartKeyLen=1, NonPartKeyLen=7, DataLen=20
The recovery log is pinned by a dirty page in the data base buffer pool. Check 
the buffer pool
statistics. If the associated transaction is still active then more information 
will be displayed
about that transaction. 
Database buffer pool global variables: 
CkptId=25232, NumClean=269056, MinClean=393192, NumTempClean=393216, 
MinTempClean=196596,
BufPoolSize=393216, BufDescCount=432537, BufDescMaxFree=432537,
DpTableSize=393216, DpCount=124149, DpDirty=124149, DpCkptId=21890, 
DpCursor=92805,
NumEmergency=0 CumEmergency=0, MaxEmergency=0.
BuffersXlatched=0, xLatchesStopped=False, FullFlushWaiting=False.

Is the large number of DpDirty pages bad?  I think so, but I don't know the 
techincal details behind this value.  The log is at 0% util when backups start 
during the evening and by midnight last night, the log was up to 80% and 
climbing rapidly.  Once I cancel these 4 clients from backing up, the log stops 
filling so rapidly.  Does anyone else have problems with clients that have 
large numbers of small files?  How do you handle backing them up?  It seems 
like these nodes take 8-10 hours a piece which seems very slow.

Thanks in advance for any assistance that you can provide!

Michael French
Savvis Communications
IDS01 Santa Clara, CA
(408)450-7812 -- desk
(408)239-9913 -- mobile