Seagate/Conner CTT8000S problem on FreeBSD

[Sorin Chiorean]

Hi,

I'm running FreeBSD  5.1-RELEASE-p8 on a Pentium II with SCSI adapter  

..kernel: ahc0: <Adaptec 2940 Ultra SCSI adapter> port 0xb800-0xb8ff mem
0xe2800000-0xe2800fff irq 10 at device 11.0 on pci0
..kernel: aic7880: Ultra Wide Channel A, SCSI Id=7, 16/253 SCBs

and with the following tape:
..kernel: sa0 at ahc0 bus 0 target 6 lun 0
..kernel: sa0: <CONNER CTT8000-S 1.17> Removable Sequential Access
SCSI-2 device
..kernel: sa0: 5.000MB/s transfers (5.000MHz, offset 15)

I tried to backup up on a 8Gb(compress)TRAVAN TR-4 tape, 4.4Gb of data
and didn't work.
I used tar and dump and I ended up with the same problem: I can not
backup up more then 4Gba on /dev/sa0 or /dev/nsa0.
It's seems that hardware compression doesn't work on FreeBSD. Was
working fine on a Windows 2000 server before.

I tried to change Compression with "#mt -f /dev/sa0 comp enable" but
didn't work (I tried with "comp on" too)
This is what I get after a "#mt status":
 
Mode      Density              Blocksize      bpi      Compression
Current:  0x45                 variable       0        disabled
---------available modes---------
0:        0x45                 variable       0        none
1:        0x45                 variable       0        none
2:        0x45                 variable       0        none
3:        0x45                 variable       0        none
---------------------------------
Current Driver State: at rest.
---------------------------------
File Number: 0  Record Number: 0        Residual Count 28

Can anybody tell me how can I turn on hardware compression for this tape
unit or what can I do to be able to buck up more then 4Gb ??


Sorin Chiorean
Network Specialist
Computer Partners