Ignite and maxdsize parameter

[Thomas VERPILLOT_1]

Hello,

I'm trying to install a wks with kernel parameters modified. All is OK except for the maxdsize value that stay to 3221225472. I try to change it to 4294963200. If I do it manually in sam, all is OK and the good value appears at the wks reboot.

Is it an Ignite Problem or an logical error ?

regards
Thomas

INDEX :
cfg "11.11 C3750 HE WKS TEST" {
description "System configuration supplied for the B.11.11 HE Wks on C3750 model."
"/opt/ignite/data/Rel_B.11.11/C3750HE"
"/var/opt/ignite/data/Rel_B.11.11/core_700_archive_cfg_HE"
"/opt/ignite/data/Rel_B.11.11/hw_patches_cfg"
"/var/opt/ignite/config.C3750HE"
}=TRUE

/var/opt/ignite/config.C3750HE:
HARDWARE_MODEL ~ "9000/785/C3750" {
######################
## Kernel for C3750 ##
######################
mod_kernel += "maxdsiz 4294963200"
mod_kernel += "bufpages 0"
mod_kernel += "create_fastlinks 1"
mod_kernel += "dbc_max_pct 20"
mod_kernel += "dbc_max_pct 20"
mod_kernel += "default_disk_ir 1"
mod_kernel += "fs_async 1"
mod_kernel += "hpux_aes_override 1"
mod_kernel += "large_ncargs_enabled 1"
mod_kernel += "maxfiles 2048"
mod_kernel += "maxfiles_lim 2048"
mod_kernel += "maxssiz 100610048"
mod_kernel += "maxswapchunks 16384"
mod_kernel += "maxtsiz 1073741800"
mod_kernel += "maxuprc 3277"
mod_kernel += "maxusers 124"
mod_kernel += "nfile 8192"
mod_kernel += "ninode 8192"
mod_kernel += "nproc 4096"
mod_kernel += "npty 200"
mod_kernel += "nstrpty 200"
}

[Steve Steel]

Hi

I read that the + symbol must be in front of every entry except the first


This may be the problem

try
mod_kernel = "maxdsiz 4294963200"

and rest as is

Steve Steel

[Thomas VERPILLOT_1]

Hi Steve,

I tested it, but I still have the same problem.

Thx
Thomas

[Bill Hassell]

Setting maxdsiz to a value larger than 2Gb is meaningless for most situations in a 32bit kernel. The maximum addressable size available for a 32bit program is 960megs or about 1750megs for EXEC_MAGIC executables. While you can play with compiler options and some restrictions in a special program to get more than 3Gb, 4Gb is impossible for 32bit programs.

Some of your other parameters are suspect:

default_disk_ir 1 will turn on immediate reportingfor every disk. However, unless every disk (including internal) has a battery backup, it will create a risk for losing data stored in the disk's cache.

fs_async 1 causes all directory and inode structure changes to be cached along with user data. If you system is busy, then crashes or has a power failure, you are almost guarenteed to have filesystem corruption that cannot be repaired. Note that both default_disk_ir=1 and fs_async=1 *will* increase disk performance, but at the risk of severe data loss with a powerfail.

maxfiles = maxfile_lim is a common, but misguided vendor recommendation. maxfiles is used to prevent runaway programs from using all file handles and should remain low (like 50-100) to prevent system lockups. Not even root can login if all the file handles are used. maxfiles can be increased with the ulimit command for a specific program.

maxssiz is 100megs, probably a bit more than needed. The default is 8 megs, fine for normal programs. Programmers that dump a lot of data on the stack (not a good technique) can create programs that need dozens of megs.

maxtsiz is 1Gb, far too large for virtually any program. The default is 64megs, still far larger than the vast majority of programs. maxtsiz refers to the text area or the unchanging instructions in a program. You can predict the text size of any program by looking at the size of the executable file. If an executable is 500megs in size, then maxtsiz may need to be 500megs. Note that a 500meg program will require millions of lines of code to reach that size.

ninode 8192 is far too large unless you are running a large number of HFS filesystems (the default is VxFS). A typical system will need ninode set to about 512 to 1024.

Now none of these parameters will cause problems (except a large ninode uses extra RAM), but it is usually a good idea tolimit values to reasonable ranges.