hello everybody.
im running amanda 2.6.0P1
and i try to backup a DLE bigger than my LTO4 tape.
(850GB DLE on a 800 GB LTO4 TAPE)

when the backup starts , the amdump log says that there's not enough holding 
disk space and it dump directly to tape.

i'am surprised because i defined a tape_splitsize as defined in the manual.

another weird thing i noticed in the amdump log. the tapelengt is about twice 
as big as my tape definition (1581252608 KB VS 772096 mbytes)

Is it a normal behavior?

here's a sample of my amanda.conf



 holdingdisk hd1 {
        comment "Temporary holding space"
        directory "/var/tmp/amanda"
        use -5000 MB # use all but 5gb
        chunksize 2Gb
   }

define tapetype HP-ULTRIUM4 {
    comment "HP Ultrium 4-SCSI (compression off)"
    length 772096 mbytes
    filemark 0 kbytes
    speed 75283 kps
}


define dumptype root-tar {
program "GNUTAR"
compress none
tape_splitsize 2Gb
fallback_splitsize      256M
split_diskbuffer "/var/tmp/amanda"
comment "root partition dump with tar"
index yes
dumpcycle 0
exclude list "/etc/amanda/fullbackup/fullbackup.exclude"
priority high
auth "bsdtcp"
holdingdisk yes
estimate calcsize
}





part of amdump log 


DELAYING DUMPS IF NEEDED, total_size 855334735, [b]tape length 
1581252608 [/b]mark 0
  delay: Total size now 855334735.

PROMOTING DUMPS IF NEEDED, total_lev0 855334639, balanced_size 855334639...
planner: time 1.306: analysis took 0.000 secs

GENERATING SCHEDULE:
--------
DUMP bkplin01 ffffffff9ffeffffffff00 /data 20080724112225 3 0 
1970:1:1:0:0:0 855334639 855334639 0 4330054624 1 
2008:7:23:8:51:27 420 420 0 1024
--------
taper: using label `FULLBACK-03' date `20080724112225'
driver: result time 11.038 from taper: TAPER-OK
driver: state time 11.038 free kps: 100000 space: 37982208 
taper: idle idle-dumpers: 4 qlen tapeq: 0 runq: 0 roomq: 0 
wakeup: 0 driver-idle: not-idle
driver: interface-state time 11.038 if default: free 100000
driver: hdisk-state time 11.038 hdisk 0: free 37982208 dumpers 0
driver: flush size 0
find diskspace: not enough diskspace. Left with 817353088 K
driver: dumping bkplin01:/data directly to tape



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