[Veritas-bu] slow backup on LTO2 drives

        Hi,

What is your st patch level ? (108725-XX )

Did you try to tune size data buffers ?

Hth

Fabrice

-----Message d'origine-----
De : Fabien.LIOU AT fr.thalesgroup DOT com
[mailto:Fabien.LIOU AT fr.thalesgroup DOT com]
Envoyé : jeudi 11 septembre 2003 17:23
À : veritas-bu AT mailman.eng.auburn DOT edu
Objet : [Veritas-bu] slow backup on LTO2 drives


Hello,


I've a STK L700 library with 4 LTO2 drives.
My master NBU server is under Solaris8 (with latest kernel patch and LTO2
patch)  with NBU4.5fp5

Interfaces between drives and master are 2gigabit.
Switch is a sphereon 4500



My st.conf file is:

tape-config-list=

        "IBM     ULTRIUM-TD2",  "IBM Ultrium-2",
"CLASS_LTO2",    
        "IBM     ULT3580-TD2",  "IBM 3580 Ultrium-2",
"CLASS_LTO2";    
 

CLASS_LTO2      =       1,0x3B,0,0x45863d,2,0x40,0x42,1;

 

name="st" class="scsi"

        target=0 lun=0;

 

name="st" class="scsi"

        target=1 lun=0;

 

name="st" class="scsi"

        target=2 lun=0;

 

name="st" class="scsi"

        target=3 lun=0;

 

name="st" class="scsi"

        target=4 lun=0;

 

name="st" class="scsi"

        target=5 lun=0;

 

name="st" class="scsi"

        target=6 lun=0;

 

name="st" class="scsi"

        target=7 lun=0;

 

name="st" class="scsi"

        target=8 lun=0;

 

 

name="st" class="scsi"

        target=9 lun=0;

 

name="st" class="scsi"

        target=10 lun=0;

 

name="st" class="scsi"

        target=11 lun=0;

 

name="st" class="scsi"

        target=12 lun=0;

name="st" parent="fp" target=0;



My sg.conf is:

# Configuration file for SCSA Generic.
#
name="sg" class="scsi" target=0 lun=0;
name="sg" class="scsi" target=0 lun=1;
name="sg" class="scsi" target=1 lun=0;
name="sg" class="scsi" target=1 lun=1;
name="sg" class="scsi" target=2 lun=0;
name="sg" class="scsi" target=2 lun=1;
name="sg" class="scsi" target=3 lun=0;
name="sg" class="scsi" target=3 lun=1;
name="sg" class="scsi" target=4 lun=0;
name="sg" class="scsi" target=4 lun=1;
name="sg" class="scsi" target=5 lun=0;
name="sg" class="scsi" target=5 lun=1;
name="sg" class="scsi" target=6 lun=0;
name="sg" class="scsi" target=6 lun=1;
name="sg" class="scsi" target=7 lun=0;
name="sg" class="scsi" target=7 lun=1;
name="sg" class="scsi" target=8 lun=0;
name="sg" class="scsi" target=8 lun=1;
name="sg" class="scsi" target=9 lun=0;
name="sg" class="scsi" target=9 lun=1;
name="sg" class="scsi" target=10 lun=0;
name="sg" class="scsi" target=10 lun=1;
name="sg" class="scsi" target=11 lun=0;
name="sg" class="scsi" target=11 lun=1;
name="sg" class="scsi" target=12 lun=0;
name="sg" class="scsi" target=12 lun=1;


When i do a "dd", performance seems to be ok (30Mo/s).
But when i use NBU, i usually obtain 5Mo/s locally or remotely!!


Does anyone can point me to the misconfiguration ?


Thanks.


Fabien 

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