Introduction
You may need to modify your HP-UX 11i kernel in some way, such as changing a kernel parameter, and then rebuild your kernel. You may need to create a new HP-UX kernel in order to add device drivers or subsystems, to tune the kernel to get improved performance, to alter configurable parameters, or to change the dump and swap devices. If you update or modify a dynamic element of your kernel, as shown in the example in this chapter, a reboot is not required. Updating or modifying a static element requires a reboot and may also require some additional steps.
With HP-UX 11i it is not necessary to rebuild your kernel for all changes that take place to it. In 11i, there are many Dynamically Tunable Kernel Parameters and Dynamically Loadable Kernel Modules that will modify your kernel but not require a reboot. Combined with many Dynamic Patches that are available in 11i, you will need to reboot your system less often. We'll cover the following two topics in this chapter:
Manually build an HP-UX kernel - In the next section, we'll modify a Dynamically Tunable Kernel Parameter, thereby modifying the kernel, and do not have to reboot the system in order for the change to take place. We'll then make a change to the kernel and fully rebuild it so you can see the process of a complete rebuild, including a reboot. In this chapter, I discuss various commands related to kernel generation and cover the process by which you would manually create a kernel.
Use kcweb to view, modify, and monitor the kernel - kcweb is a new Web-based kernel just becoming available at the time of this writing. Many such Web-based tools are planned for HP-UX, so we'll work with kcweb to perform many kernel-related functions.
Building a Kernel
New with 11i (first introduced in 11.0) was the introduction of dynamically loadable kernel modules. In 11.x, the infrastructure for this feature was put into place, providing a separate system file for each module. With 11.0 is provided the ability of specially created modules to be loaded or unloaded into the kernel without having to reboot the system as long as the module is not being used. HP-UX 11i continues to support all of this dynamic functionality. This new mechanism provides great flexibility and improved system uptime. Detailed information about this advanced feature can be reviewed in the HP-UX 11.x Release Notes. Most of the dynamically loadable kernel modules available at the time of this writing are third party. The IT Resource Center Web site (itrc.hp.com) contains information on this topic, including a developer's guide.
To begin, let's take a look at an existing kernel running on an HP-UX 11i L-Class system used in many of the examples throughout this book. The sysdef command is used to analyze and report tunable parameters of a currently running system. You can specify a particular file to analyze if you don't wish to use the currently running system. The following is a partial listing of having run sysdef on an 11i L-Class system:
# /usr/sbin/sysdef
NAME VALUE BOOT MIN-MAX UNITS FLAGS
acctresume 4 - -100-100 -
acctsuspend 2 - -100-100 -
allocate_fs_swapmap 0 - - -
bufpages 32074 - 0- Pages -
create_fastlinks 0 - - -
dbc_max_pct 50 - - -
dbc_min_pct 5 - - -
default_disk_ir 0 - - -
dskless_node 0 - 0-1 -
eisa_io_estimate 768 - - -
eqmemsize 23 - - -
file_pad 10 - 0- -
fs_async 0 - 0-1 -
hpux_aes_override 0 - - -
maxdsiz 2 - 0-655360 Pages -
maxdsiz_64bit 16384 - 256-1048576 Pages -
maxfiles 60 - 30-2048 -
maxfiles_lim 1024 - 30-2048 -
maxssiz 65536 - 0-655360 Pages -
maxssiz_64bit 262144 - 256-1048576 Pages -
maxswapchunks 512 - 1-16384 -
maxtsiz 2048 - 0-655360 Pages -
maxtsiz_64bit 2048 - 256-1048576 Pages -
maxuprc 75 - 3- -
maxvgs 10 - - -
msgmap 2555904 - 3- -
nbuf 18720 - 0- -
ncallout 515 - 6- -
ncdnode 150 - - -
ndilbuffers 30 - 1- -
netisr_priority -1 - -1-127 -
netmemmax 0 - - -
nfile 920 - 14- -
nflocks 200 - 2- -
ninode 476 - 14- -
no_lvm_disks 0 - - -
nproc 400 - 10- -
npty 60 - 1- -
nstrpty 60 - - -
nswapdev 10 - 1-25 -
nswapfs 10 - 1-25 -
public_shlibs 1 - - -
remote_nfs_swap 0 - - -
rtsched_numpri 32 - - -
sema 0 - 0-1 -
semmap 4128768 - 4- -
shmem 0 - 0-1 -
shmmni 200 - 3-1024 -
streampipes 0 - 0- -
swapmem_on 1 - - -
swchunk 2048 - 2048-16384 kBytes -
timeslice 10 - -1-2147483648 Ticks -
unlockable_mem 1800 - 0- Pages -
#
In addition to the tunable parameters, you may want to see a report of all the hardware found on your system. The ioscan command does this for you. Using sysdef and ioscan, you can see what your tunable parameters are set to and what hardware exists on your system. You will then know how your system is set up and can then make changes to your kernel. The following is an ioscan output of the same HP-UX 11i L-Class system for which sysdef was run:
# /usr/sbin/ioscan -f
Class I H/W Path Driver S/W State H/W Type Description
===========================================================================
root 0 root CLAIMED BUS_NEXUS
ioa 0 0 sba CLAIMED BUS_NEXUS System Bus Adapter (582)
ba 0 0/0 lba CLAIMED BUS_NEXUS Local PCI Bus Adapter (782)
lan 0 0/0/0/0 btlan CLAIMED INTERFACE HP PCI 10/100Base-TX Core
ext_bus 0 0/0/1/0 c720 CLAIMED INTERFACE SCSI C896 Fast Wide LVD
target 0 0/0/1/0.7 tgt CLAIMED DEVICE
ctl 0 0/0/1/0.7.0 sctl CLAIMED DEVICE Initiator
ext_bus 1 0/0/1/1 c720 CLAIMED INTERFACE
SCSI C896 Ultra Wide Single-Ended
target 1 0/0/1/1.2 tgt CLAIMED DEVICE
disk 1 0/0/1/1.2.0 sdisk CLAIMED DEVICE SEAGATE ST318203LC
target 2 0/0/1/1.7 tgt CLAIMED DEVICE
ctl 1 0/0/1/1.7.0 sctl CLAIMED DEVICE Initiator
ext_bus 2 0/0/2/0 c720 CLAIMED INTERFACE SCSI C875 Ultra
Wide Single-Ended
target 3 0/0/2/0.2 tgt CLAIMED DEVICE
disk 2 0/0/2/0.2.0 sdisk CLAIMED DEVICE SEAGATE ST318203LC
target 4 0/0/2/0.7 tgt CLAIMED DEVICE
ctl 2 0/0/2/0.7.0 sctl CLAIMED DEVICE Initiator
ext_bus 3 0/0/2/1 c720 CLAIMED INTERFACE
SCSI C875 Ultra Wide Single-Ended
target 5 0/0/2/1.4 tgt CLAIMED DEVICE
disk 3 0/0/2/1.4.0 sdisk CLAIMED DEVICE TOSHIBA CD-ROM XM-6201TA
target 6 0/0/2/1.7 tgt CLAIMED DEVICE
ctl 3 0/0/2/1.7.0 sctl CLAIMED DEVICE Initiator
tty 0 0/0/4/0 asio0 CLAIMED INTERFACE PCI Serial (103c1048)
tty 1 0/0/5/0 asio0 CLAIMED INTERFACE PCI Serial (103c1048)
ba 1 0/1 lba CLAIMED BUS_NEXUS Local PCI Bus Adapter (782)
ba 2 0/2 lba CLAIMED BUS_NEXUS Local PCI Bus Adapter (782)
ba 3 0/3 lba CLAIMED BUS_NEXUS Local PCI Bus Adapter (782)
lan 1 0/3/0/0 btlan CLAIMED INTERFACE
HP A5230A/B5509BA PCI 10/100Base-TX Addon
ba 4 0/4 lba CLAIMED BUS_NEXUS Local PCI Bus Adapter (782)
ext_bus 4 0/4/0/0 c720 CLAIMED INTERFACE
C875 Fast Wide Differential
target 7 0/4/0/0.7 tgt CLAIMED DEVICE
ctl 4 0/4/0/0.7.0 sctl CLAIMED DEVICE Initiator
ext_bus 5 0/4/0/1 c720 CLAIMED INTERFACE SCSI C875 Fast
Wide Differential
target 8 0/4/0/1.7 tgt CLAIMED DEVICE
ctl 5 0/4/0/1.7.0 sctl CLAIMED DEVICE Initiator
ba 5 0/5 lba CLAIMED BUS_NEXUS Local PCI Bus Adapter (782)
ba 6 0/6 lba CLAIMED BUS_NEXUS Local PCI Bus Adapter (782)
ba 7 0/7 lba CLAIMED BUS_NEXUS Local PCI Bus Adapter (782)
ext_bus 6 0/7/0/0 c720 CLAIMED INTERFACE
SCSI C875 Fast Wide Differential
target 9 0/7/0/0.7 tgt CLAIMED DEVICE
ctl 6 0/7/0/0.7.0 sctl CLAIMED DEVICE Initiator
ext_bus 7 0/7/0/1 c720 CLAIMED INTERFACE
SCSI C875 Fast Wide Differential
target 10 0/7/0/1.7 tgt CLAIMED DEVICE
ctl 7 0/7/0/1.7.0 sctl CLAIMED DEVICE Initiator
memory 0 8 memory CLAIMED MEMORY Memory
processor 0 160 processor CLAIMED PROCESSOR Processor
processor 1 166 processor CLAIMED PROCESSOR Processor
#
I normally run ioscan with the -f option because it includes the Driver, S/W State, and H/W Type columns. I am interested in the driver associated with the hardware in the system that the -f option produces.
The ioscan output shows all of the hardware that comprises the system, including the two processors in the system.
The file /stand/vmunix is the currently running kernel. Here is a long listing of the directory /stand on the L-Class system, which shows the file /stand/vmunix:
# ls -l
total 74274
-rw-r--r-- 1 root sys 19 Aug 4 11:37 bootconf
drwxr-xr-x 4 root sys 2048 Aug 25 11:24 build
drwxr-xr-x 5 root sys 1024 Aug 24 13:00 dlkm
drwxr-xr-x 5 root sys 1024 Aug 4 12:45 dlkm.vmunix.prev
-rw-r--r-- 1 root sys 3024 Aug 4 12:26 ioconfig
-r--r--r-- 1 root sys 82 Aug 4 12:27 kernrel
drwxr-xr-x 2 root sys 1024 Aug 29 11:39 krs
drwxr-xr-x 2 root root 1024 Aug 29 11:33 krs_lkg
drwxr-xr-x 2 root root 1024 Aug 29 11:39 krs_tmp
drwxr-xr-x 2 root root 8192 Aug 4 11:36 lost+found
-rw------- 1 root root 12 Aug 29 11:33 rootconf
-rw-rw-rw- 1 root sys 1180 Aug 24 12:52 system
-r--r--r-- 1 root sys 1026 Aug 4 12:21 system.prev
-rwxr-xr-x 1 root sys 14774416 Aug 24 12:53 vmunix
-rwxr-xr-x 1 root sys 23184584 Aug 4 12:22 vmunix.prev
#
Notice that among the directories shown are two related to Dynamically Loadable Kernel Modules (DLKM). These are kernel modules that can be included in the kernel without having to reboot the system.
In order to make a change to the kernel, we would change to the /stand/build directory, where all work in creating a new kernel is performed, and issue the system_prep command as shown below:
We can now proceed to make the desired changes to the kernel, including adding a driver or subsystem such as cdfs for a CD-ROM file system. With the dynamically loadable kernel module (DLKM) structure in place with 11i, we must use kmsystem and kmtune to make changes to the kernel system and system description files.
You can use kmtune to view the value and parameters related to existing kernel parameters as well as to make proposed modifications to the kernel. The following listing shows issuing kmtune (without the -l option to view details) to view a summary of the currently running kernel:
# kmtune
Parameter Current Dyn Planned Module Version
===============================================================================
NSTRBLKSCHED - - 2
NSTREVENT 50 - 50
NSTRPUSH 16 - 16
NSTRSCHED 0 - 0
STRCTLSZ 1024 - 1024
STRMSGSZ 65535 - 65535
acctresume 4 - 4
acctsuspend 2 - 2
aio_listio_max 256 - 256
aio_max_ops 2048 - 2048
aio_physmem_pct 10 - 10
aio_prio_delta_max 20 - 20
allocate_fs_swapmap 0 - 0
alwaysdump 1 - 1
bootspinlocks - - 256
bufcache_hash_locks 128 - 128
bufpages 0 - 0
chanq_hash_locks 256 - 256
create_fastlinks 0 - 0
dbc_max_pct 50 - 50
dbc_min_pct 5 - 5
default_disk_ir 0 - 0
desfree - - 0
disksort_seconds 0 - 0
dnlc_hash_locks 512 - 512
dontdump 0 - 0
dskless_node - - 0
dst 1 - 1
effective_maxpid - - ((NPROC<22500)?30000:(NPROC*5/4))
eisa_io_estimate - - 0x300
enable_idds 0 - 0
eqmemsize 15 - 15
executable_stack 1 - 1
fcp_large_config 0 - 0
file_pad - - 10
fs_async 0 - 0
ftable_hash_locks 64 - 64
hdlpreg_hash_locks 128 - 128
hfs_max_ra_blocks 8 - 8
hfs_max_revra_blocks 8 - 8
hfs_ra_per_disk 64 - 64
hfs_revra_per_disk 64 - 64
hp_hfs_mtra_enabled 1 - 1
hpux_aes_override - - 0
initmodmax 50 - 50
io_ports_hash_locks 64 - 64
iomemsize - - 40000
ksi_alloc_max 2208 - 2208
ksi_send_max 32 - 32
lotsfree - - 0
max_async_ports 50 - 50
max_fcp_reqs 512 - 512
max_mem_window 0 - 0
max_thread_proc 64 - 64
maxdsiz 0x10000000 - 0x10000000
maxdsiz_64bit 0x40000000 - 0X40000000
maxfiles 60 - 60
maxfiles_lim 1024 Y 1024
maxqueuetime - - 0
maxssiz 0x800000 - 0X800000
maxssiz_64bit 0x800000 - 0X800000
maxswapchunks 512 - 512
maxtsiz 0x4000000 Y 0X4000000
maxtsiz_64bit 0x40000000 Y 0x40000000
maxuprc 77 Y 77
maxusers 32 - 32
maxvgs 10 - 10
mesg 1 - 1
minfree - - 0
modstrmax 500 - 500
msgmap 42 - 42
msgmax 8192 Y 8192
msgmnb 16384 Y 16384
msgmni 50 - 50
msgseg 2048 - 2048
msgssz 8 - 8
msgtql 40 - 40
nbuf 0 - 0
ncallout 515 - 515
ncdnode 150 - 150
nclist 612 - 612
ncsize 5596 - 5596
ndilbuffers 30 - 30
netisr_priority - - -1
netmemmax - - 0
nfile 910 - 910
nflocks 200 - 200
nhtbl_scale 0 - 0
ninode 476 - 476
nkthread 499 - 499
nni - - 2
no_lvm_disks 0 - 0
nproc 400 - 500
npty 60 - 60
nstrpty 60 - 60
nstrtel 60 - 60
nswapdev 10 - 10
nswapfs 10 - 10
nsysmap 800 - 800
nsysmap64 800 - 800
num_tachyon_adapters 0 - 0
o_sync_is_o_dsync 0 - 0
page_text_to_local - - 0
pfdat_hash_locks 128 - 128
public_shlibs 1 - 1
region_hash_locks 128 - 128
remote_nfs_swap 0 - 0
rtsched_numpri 32 - 32
scroll_lines 100 - 100
scsi_maxphys 1048576 - 1048576
sema 1 - 1
semaem 16384 - 16384
semmap 66 - 66
semmni 64 - 64
semmns 128 - 128
semmnu 30 - 30
semume 10 - 10
semvmx 32767 - 32767
sendfile_max 0 - 0
shmem 1 - 1
shmmax 0x4000000 Y 0X4000000
shmmni 200 - 200
shmseg 120 Y 120
st_ats_enabled 1 - 1
st_fail_overruns 0 - 0
st_large_recs 0 - 0
streampipes 0 - 0
swapmem_on 1 - 1
swchunk 2048 - 2048
sysv_hash_locks 128 - 128
tcphashsz 0 - 0
timeslice 10 - 10
timezone 420 - 420
unlockable_mem 0 - 0
vas_hash_locks 128 - 128
vnode_cd_hash_locks 128 - 128
vnode_hash_locks 128 - 128
vps_ceiling 16 - 16
vps_chatr_ceiling 1048576 - 1048576
vps_pagesize 4 - 4
vx_fancyra_enable 0 - 0
vx_maxlink 32767 - 32767
vx_ncsize 1024 - 1024
vxfs_max_ra_kbytes 1024 - 1024
vxfs_ra_per_disk 1024 - 1024
#
Issuing kmtune with the -l option produces a detailed listing of the kernel. The following shows just the output for one of the parameters:
# kmtune -l
Parameter: maxuprc
Current: 77
Planned: 77
Default: 75
Minimum: -
Module: -
Version: -
Dynamic: Yes
#
This parameter is Dynamic (Yes) meaning that the kernel can be dynamically updated. After having viewed this output we can now modify the value of this dynamic parameter. The following command changes the value of the following parameter from 77, which is the existing value, to 80:
We can now issue the kmtune to again view the existing and proposed value of the maxuprc parameter:
# kmtune
Parameter Current Dyn Planned Module Version
===============================================================================
NSTRBLKSCHED - - 2
NSTREVENT 50 - 50
NSTRPUSH 16 - 16
NSTRSCHED 0 - 0
STRCTLSZ 1024 - 1024
STRMSGSZ 65535 - 65535
acctresume 4 - 4
acctsuspend 2 - 2
aio_listio_max 256 - 256
aio_max_ops 2048 - 2048
aio_physmem_pct 10 - 10
aio_prio_delta_max 20 - 20
allocate_fs_swapmap 0 - 0
alwaysdump 1 - 1
bootspinlocks - - 256
bufcache_hash_locks 128 - 128
bufpages 0 - 0
chanq_hash_locks 256 - 256
create_fastlinks 0 - 0
dbc_max_pct 50 - 50
dbc_min_pct 5 - 5
default_disk_ir 0 - 0
desfree - - 0
disksort_seconds 0 - 0
dnlc_hash_locks 512 - 512
dontdump 0 - 0
dskless_node - - 0
dst 1 - 1
effective_maxpid - - ((NPROC<22500)?30000:(NPROC*5/4))
eisa_io_estimate - - 0x300
enable_idds 0 - 0
eqmemsize 15 - 15
executable_stack 1 - 1
fcp_large_config 0 - 0
file_pad - - 10
fs_async 0 - 0
ftable_hash_locks 64 - 64
hdlpreg_hash_locks 128 - 128
hfs_max_ra_blocks 8 - 8
hfs_max_revra_blocks 8 - 8
hfs_ra_per_disk 64 - 64
hfs_revra_per_disk 64 - 64
hp_hfs_mtra_enabled 1 - 1
hpux_aes_override - - 0
initmodmax 50 - 50
io_ports_hash_locks 64 - 64
iomemsize - - 40000
ksi_alloc_max 2208 - 2208
ksi_send_max 32 - 32
lotsfree - - 0
max_async_ports 50 - 50
max_fcp_reqs 512 - 512
max_mem_window 0 - 0
max_thread_proc 64 - 64
maxdsiz 0x10000000 - 0x10000000
maxdsiz_64bit 0x40000000 - 0X40000000
maxfiles 60 - 60
maxfiles_lim 1024 Y 1200
maxqueuetime - - 0
maxssiz 0x800000 - 0X800000
maxssiz_64bit 0x800000 - 0X800000
maxswapchunks 512 - 512
maxtsiz 0x4000000 Y 0X4000000
maxtsiz_64bit 0x40000000 Y 0X40000000
maxuprc 77 Y 80
maxusers 32 - 32
maxvgs 10 - 10
mesg 1 - 1
minfree - - 0
modstrmax 500 - 500
msgmap 42 - 42
msgmax 8192 Y 8192
msgmnb 16384 Y 16384
msgmni 50 - 50
msgseg 2048 - 2048
msgssz 8 - 8
msgtql 40 - 40
nbuf 0 - 0
ncallout 515 - 515
ncdnode 150 - 150
nclist 612 - 612
ncsize 5596 - 5596
ndilbuffers 30 - 30
netisr_priority - - -1
netmemmax - - 0
nfile 910 - 910
nflocks 200 - 200
nhtbl_scale 0 - 0
ninode 476 - 476
nkthread 499 - 499
nni - - 2
no_lvm_disks 0 - 0
nproc 400 - 400
npty 60 - 60
nstrpty 60 - 60
nstrtel 60 - 60
nswapdev 10 - 10
nswapfs 10 - 10
nsysmap 800 - 800
nsysmap64 800 - 800
num_tachyon_adapters 0 - 0
o_sync_is_o_dsync 0 - 0
page_text_to_local - - 0
pfdat_hash_locks 128 - 128
public_shlibs 1 - 1
region_hash_locks 128 - 128
remote_nfs_swap 0 - 0
rtsched_numpri 32 - 32
scroll_lines 100 - 100
scsi_maxphys 1048576 - 1048576
sema 1 - 1
semaem 16384 - 16384
semmap 66 - 66
semmni 64 - 64
semmns 128 - 128
semmnu 30 - 30
semume 10 - 10
semvmx 32767 - 32767
sendfile_max 0 - 0
shmem 1 - 1
shmmax 0x4000000 Y 0X4000000
shmmni 200 - 200
shmseg 120 Y 120
st_ats_enabled 1 - 1
st_fail_overruns 0 - 0
st_large_recs 0 - 0
streampipes 0 - 0
swapmem_on 1 - 1
swchunk 2048 - 2048
sysv_hash_locks 128 - 128
tcphashsz 0 - 0
timeslice 10 - 10
timezone 420 - 420
unlockable_mem 0 - 0
vas_hash_locks 128 - 128
vnode_cd_hash_locks 128 - 128
vnode_hash_locks 128 - 128
vps_ceiling 16 - 16
vps_chatr_ceiling 1048576 - 1048576
vps_pagesize 4 - 4
vx_fancyra_enable 0 - 0
vx_maxlink 32767 - 32767
vx_ncsize 1024 - 1024
vxfs_max_ra_kbytes 1024 - 1024
vxfs_ra_per_disk 1024 - 1024
#
This output shows that the change to our parameter is pending.
We can apply the change to the dynamic parameter maxuprc from 77 to 80 by issuing kmtune with the -u option:
# kmtune -u
The kernel's value of maxuprc has been set to 80 (0x50).
#
This output shows that the change we wanted made to the kernel has been made. We can confirm this by running kmtune again and searching for maxuprc:
Both the Current and Planned values have been updated to 80. This dynamic update can be done using kmsystem to add dynamic drivers to your kernel.
There are many other procedures for which you would have to perform additional steps to include modifications in the kernel and rebuild it. With these non-dynamic changes you would create a new kernel, which will be generated as /stand/build/vmunix_test, using the command shown below:
# mk_kernel -s system
Compiling conf.c...
Loading the kernel...
Generating kernel symbol table...
#
At this point, the new kernel exists in the /stand/build directory. The existing kernel is updated with the newly generated kernel with kmupdate. kmupdate moves the new kernel files into the /stand directory. I would first recommend moving the existing /stand/system kernel file to a backup file, and then updating the new kernel as shown below:
# mv /stand/system /stand/system.prev (may want to move additional # kmupdate /stand/build/vmunix_test files shown in Figure 4-1) Kernel update request is scheduled. Default kernel /stand/vmunix will be updated by newly built kernel /stand/build/vmunix_test at next system shutdown or startup time. #
kmupdate will automatically create backup copies of /stand/vmunix and /stand/dlkm for you. These will be created as /stand/vmunix.prev and /stand/dlkm.vmunix.prev, respectively.
You can now shut down the system and automatically boot from the new kernel if your update did not take place dynamically and requires a reboot.
Figure 4-1 summarizes the process of building a new kernel in HP-UX 11i.
There are really two different procedures for generating your kernel - one for dynamic elements, such as the parameter maxuprc shown in the earlier example, and one for static elements. The static procedure consists of several additional steps and a reboot. With HP-UX 11i, more and more kernel objects will be updated dynamically, resulting in fewer reboots when modifying your kernel.