From: Jerry Gelaude (ggelaude@SUMINET.NET)
Date: Thu Jan 30 2003 - 00:21:04 EST
Hi Michelle,
>From the following AIX 4.3 documentation link for the
/etc/security/limits file,
http://publib.boulder.ibm.com/doc_link/en_US/a_doc_lib/files/aixfiles/limits.htm
Begin Excerpt
Note: Changing the limit does not affect those processes that started
by init, or alternatively, ulimits are only used by those processes
that go through the login processes
The /etc/security/limits file defines process resource limits for
users. This file is an ASCII file that contains stanzas that specify
the process resource limits for each user. These limits are set by
individual attributes within a stanza.
Each stanza is identified by a user name followed by a colon, and
contains attributes in the Attribute=Value form. Each attribute is
ended by a new-line character, and each stanza is ended by an
additional new-line character. If you do not define an attribute for a
user, the system applies default values.
If the hard values are not explicitly defined in the
/etc/security/limits file but the soft values are, the system
substitutes the following values for the hard limits:
Resource Hard Value
Core Size unlimited
CPU Time cpu
Data Size unlimited
File Size fsize
Memory Size unlimited
Stack Size unlimited
File Descriptors unlimited
If the hard values are explicitly defined but the soft values are not,
the system sets the soft values equal to the hard values.
core Specifies the soft limit for the largest core file a user's
process can create.
fsize Identifies the soft limit for the largest file a user's process
can create or extend.
Note: Use a value of -1 to set a resource to unlimited.
Except for the cpu attribute, each attribute must be a decimal integer
string representing the number of 512-byte blocks allotted to the
user. The cpu attribute is a decimal integer string representing the
amount of system unit time in seconds.
End Excerpt
If there is a value of
core = -1
and the hard value is
core_hard = 4096
The maximum core file size limit should be 4096 times 512 byte blocks
or 2097152 bytes as the hard_core limit.
If there is a core of
core = -1
fsize = -1
and no entry for core_hard, then the core size will be unlimited.
Michelle, I think that you may be correct. Per the 4.3.3
documentation, there doesn't appear to be any size limit on the core
file. If your "core_hard" value is not set, the documentation is a
little vague as to if the "fsize" value, which Aaron mentioned, would
stop the core dump. Are your "fsize" values set to a block value or
are they -1. If they are -1, then you are large file enabled and if
there is no "core_hard" value set, there is cause for concern.
I wish you the best of luck on your new assignment.
Regards,
Jerry Gelaude
AIX 4.3 Documnetation pages
http://publib.boulder.ibm.com/cgi-bin/ds_form?lang=en_US&viewset=AIX
AIX 5L Documentation pages
http://publibn.boulder.ibm.com/cgi-bin/ds_form?lang=en_US&viewset=AIX
On Wed, 29 Jan 2003 17:02:13 -0500, you wrote:
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>
>I will take a stab at this. I think there are 2 limiting factors if
>core is set to -1:
>
>1. If the file system is not large file enabled, the core can only be
>1GB.
>2. "fsize" in /etc/security/limits
>
>At 12:17 PM 1/29/2003 -0800, you wrote:
>I've inherited the job of admin'ing several AIX
>servers. I noticed today while looking through the
>/etc/security/limits file that several users have core
>set to -1, which according to the note implies an
>"unlimited" value. I'm on my way down to talk to
>these users (they are all IT dept people, not just
>Joe-Blow users) to find out why this is so.
>
>However, I would like to know is there an instance
>anyone can think of why core would need to be set to
>- -1?
>
>Does that not imply that if a core dump starts, if it
>needs to, it will continue to write the core file
>until the fssize is met? In most cases, fssize is set
>to -1 as well, so wouldn't that mean that the
>filesystem could potentially fill up with a core file?
>
>Thanks,
>M
>
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