Mar 12 16:00:41 freebsd kernel: ciss1: adapter claims to report absurd number of logical drives (24 > 15)
A quick check on the driver source code showed up that there is a hard limit defined to 15.(/usr/src/sys/dev/ciss/cissvar.h)
#define CISS_MAX_LOGICAL 15
So I wanted to be sure if I change the number to a higher value , won't do any unwanted behavior later on the system. In that point I contacted Paul Saab where he explained the limit as below.
really that's done to limit the amount of memory needed upfront by the driver. I believe you can easily increase the number of drives without issue as long as you have enough memory below 4GB. Parts of the ciss driver require that the memory you DMA from be under 4G
After the clarification, I just set the number to 32 and rebuild/install the kernel, restart the machine and a quick check on dmesg showed up all my 24 logical volumes presented on HP P800 controller.
Mar 13 10:32:37 freebsd kernel: da19: 286070MB (585871964 512 byte sectors: 255H 32S/T 65535C) Mar 13 10:32:37 freebsd kernel: da20 at ciss1 bus 0 scbus2 target 19 lun 0 Mar 13 10:32:37 freebsd kernel: da20:Fixed Direct Access SCSI-5 device Mar 13 10:32:37 freebsd kernel: da20: 135.168MB/s transfers Mar 13 10:32:37 freebsd kernel: da20: Command Queueing enabled Mar 13 10:32:37 freebsd kernel: da20: 286070MB (585871964 512 byte sectors: 255H 32S/T 65535C) Mar 13 10:32:37 freebsd kernel: da21 at ciss1 bus 0 scbus2 target 20 lun 0 Mar 13 10:32:37 freebsd kernel: da21: Fixed Direct Access SCSI-5 device Mar 13 10:32:37 freebsd kernel: da21: 135.168MB/s transfers Mar 13 10:32:37 freebsd kernel: da21: Command Queueing enabled Mar 13 10:32:37 freebsd kernel: da21: 286070MB (585871964 512 byte sectors: 255H 32S/T 65535C) Mar 13 10:32:37 freebsd kernel: da22 at ciss1 bus 0 scbus2 target 21 lun 0 Mar 13 10:32:37 freebsd kernel: da22: Fixed Direct Access SCSI-5 device Mar 13 10:32:37 freebsd kernel: da22: 135.168MB/s transfers Mar 13 10:32:37 freebsd kernel: da22: Command Queueing enabled Mar 13 10:32:37 freebsd kernel: da22: 286070MB (585871964 512 byte sectors: 255H 32S/T 65535C) Mar 13 10:32:37 freebsd kernel: da23 at ciss1 bus 0 scbus2 target 22 lun 0 Mar 13 10:32:37 freebsd kernel: da23: Fixed Direct Access SCSI-5 device Mar 13 10:32:37 freebsd kernel: da23: 135.168MB/s transfers Mar 13 10:32:37 freebsd kernel: da23: Command Queueing enabled Mar 13 10:32:37 freebsd kernel: da23: 286070MB (585871964 512 byte sectors: 255H 32S/T 65535C) Mar 13 10:32:37 freebsd kernel: da24 at ciss1 bus 0 scbus2 target 23 lun 0 Mar 13 10:32:37 freebsd kernel: da24: Fixed Direct Access SCSI-5 device Mar 13 10:32:37 freebsd kernel: da24: 135.168MB/s transfers Mar 13 10:32:37 freebsd kernel: da24: Command Queueing enabled Mar 13 10:32:37 freebsd kernel: da24: 286070MB (585871964 512 byte sectors: 255H 32S/T 65535C)