Database Software

I have 10 database(devl,trng,qa,test,tst2..) on this server.
Devl is 1 tb database.
Suddently I see full backup of devl is failing with error


released channel: t1
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: failure of backup command on t1 channel at 05/13/2013 21:55:02
ORA-19513: failed to identify sequential file
ORA-27206: requested file not found in media management catalog
ORA-19502: write error on file "cmo9h7is_1_1", block number 22467857 (block size=16384)
ORA-27030: skgfwrt: sbtwrite2 returned error
ORA-19511: Error received from media manager layer, error text:
ANS1017E (RC-50) Session rejected: TCP/IP connection failure

all others database backup are running fine.
I can run archieve log backup fine for devl.
I talked to my tsm admin .He is seeing this error.
09:57:04 ANR0481W Session 1029097 for node (TDP
Oracle SUN) terminated - client did not respond within 3600 seconds. (SESSION: 1029097)
he asked me to try configure channel t1 type "spt_tape" maxpiecesize 65 G.
I tried ,same error.
any help/suggestion.
my os is soalris 10 and db is oracle 11gr2
I asked tsm admin to increase CommTimeOut and IDLETimeOut at a high value which he is unable to do so.


I am using this script for devl backup.





show all;
run {
allocate channel t1 type 'sbt_tape'
parms 'ENV=(TDPO_OPTFILE=/opt/tivoli/tsm/client/oracle/bin64/tdpo_devl.opt)';
CROSSCHECK BACKUP;
CROSSCHECK COPY;
backup current controlfile;
backup database;
backup spfile;
backup ARCHIVELOG all NOT BACKED UP 2 times;
CROSSCHECK archivelog all;
delete noprompt archivelog all backed up 2 times TO DEVICE TYPE sbt;
DELETE NOPROMPT OBSOLETE RECOVERY WINDOW OF 7 DAYS;
DELETE NOPROMPT EXPIRED BACKUP;
release channel t1;
}
resync catalog;