How to check the current queue depth value?

Question

I have an OEL server connected via fibre to a NetApp SAN. How can I view the queue depth as the OS sees it?

Output from lspci:

05:00.0 Fibre Channel: QLogic Corp. ISP2532-based 8Gb Fibre Channel to PCI Express HBA (rev 02)
05:00.1 Fibre Channel: QLogic Corp. ISP2532-based 8Gb Fibre Channel to PCI Express HBA (rev 02)
08:00.0 Fibre Channel: QLogic Corp. ISP2532-based 8Gb Fibre Channel to PCI Express HBA (rev 02)
08:00.1 Fibre Channel: QLogic Corp. ISP2532-based 8Gb Fibre Channel to PCI Express HBA (rev 02)

Output from lsmod:

qla2xxx              1262209  352
scsi_transport_fc      83145  1 qla2xxx
scsi_mod              199641  15 be2iscsi,ib_iser,iscsi_tcp,bnx2i,libcxgbi,libiscsi2,scsi_transport_iscsi2,scsi_dh,sr_mod,sg,qla2xxx,scsi_transport_fc,libata,cciss,sd_mod

ls /sys/class/fc_host/host*

/sys/class/fc_host/host3:
device       issue_lip  port_id    port_state  speed       subsystem          supported_speeds  system_hostname  uevent
fabric_name  node_name  port_name  port_type   statistics  supported_classes  symbolic_name     tgtid_bind_type

/sys/class/fc_host/host4:
device       issue_lip  port_id    port_state  speed       subsystem          supported_speeds  system_hostname  uevent
fabric_name  node_name  port_name  port_type   statistics  supported_classes  symbolic_name     tgtid_bind_type

/sys/class/fc_host/host5:
device       issue_lip  port_id    port_state  speed       subsystem          supported_speeds  system_hostname  uevent
fabric_name  node_name  port_name  port_type   statistics  supported_classes  symbolic_name     tgtid_bind_type

/sys/class/fc_host/host6:
device       issue_lip  port_id    port_state  speed       subsystem          supported_speeds  system_hostname  uevent
fabric_name  node_name  port_name  port_type   statistics  supported_classes  symbolic_name     tgtid_bind_type

Answer 1

On mine to NETAPP:

ls /proc/scsi/qla2xxx
1
ls /proc/scsi/qla2xxx/1 | grep -i -A1 -B1 "queue depth"
Total number of interrupts = 30686605
    Device queue depth = 0x20
Number of free request entries = 1842

So x20 is 32 in decimal, This is the # you are looking for. You can read about calculation for NETAPP here:

https://library.netapp.com/ecmdocs/ECMP1196793/html/GUID-A055B184-0876-4376-9C75-35FE8C9BE832.html

EDIT: some other method to see: cat /sys/module/qla2xxx/parameters/ql2xmaxqdepth

Answer 2

The simplest way is

cat /sys/block/<sdX>/device/queue_depth