Cta smc fails at 629 tapes

Why does this command fail at 629 tapes? These libraries have 9000+ tapes in them. Can we only list 628 tapes per query? Or are we missing a configuration option?

cta-smc -q V -N 628 |head
Vid Element Addr. Element Type
FL0378 1027 slot

cta-smc -q V -N 629
RMC02 - smc_find_cartridge error : blocksize too large (max 32720)

RMC03 - illegal function 2

Hi all, there was a limit for number of tapes in a library in smc.
There are limits in message size between smc client and smc server but also a limit for scsi request in smc server.

If I remember correctly 32760 came from scsi level at the size of smc server.

cat /proc/scsi/sg/def_reserved_size

You can try to increase it.

Here appropriate JIRA task for big lib investigation from CASTOR time [https://its.cern.ch/jira/browse/CASTOR-2984].

Hope it can be useful somehow.


[1] example for changing sg params

insmod /lib/modules/2.6.32-131.6.1.el6.x86_64/kernel/drivers/scsi/sg.ko scatter_elem_sz=4194304 def_reserved_size=33554432

Hello nononononononono8899 (please change your username to something meaningful, but definitely sorter or use a signature else we have no idea who you are),

as Victor says the reason for that failure is that def_reserved_size is too small by default and needs to be increased. Here is what we have on our tape servers:

[root@tpsrv300 ~]# cat /etc/modprobe.d/cta-tape-modules.conf
options sg def_reserved_size=2048576
# To enable maximum debug logging from the QLogic qla2xxx kernel module use this option:
# options qla2xxx ql2xextended_error_logging=0x7fffffff
options qla2xxx ql2xextended_error_logging=1

Hope this helps. Best regards,

Vladimir Bahyl