Troubleshooting
Problem
A Tivoli Storage Manager client runs an incremental backup of a large file system using the memoryefficient diskcachemethod option. The backups fails with a coredump.
Symptom
The backup shows the following messages :
# dsmc i /myfs
IBM Tivoli Storage Manager
Command Line Backup-Archive Client Interface
Client Version 6, Release 3, Level 2.1
Client date/time: 11/17/14 10:19:32
(c) Copyright by IBM Corporation and other(s) 1990, 2014. All Rights Reserved.
Node Name: MYNODE
Session established with server MYSERVER: AIX
Server Version 6, Release 3, Level 4.0
Server date/time: 11/17/14 10:19:32 Last access: 11/17/14 10:13:10
Incremental backup of volume '/myfs'
Using disk caching for backup of filespace /myfs
ANS2204E Disk cache restarted.
Memory fault(coredump)
Cause
Insufficient system limits
Diagnosing The Problem
Run the "ulimit -a" command from the same shell that ran the backup. For example :
# ulimit -a
time(seconds) unlimited
file(blocks) unlimited
data(kbytes) 131072
stack(kbytes) 32768
memory(kbytes) 32768
coredump(blocks) 2097151
nofiles(descriptors) 2000
threads(per process) unlimited
processes(per user) unlimited
In this example, it shows that data, stack, memory and nofiles are not set to unlimited.
This is what is causing the backup to crash with Memory fault.
Resolving The Problem
To temporarily change the values to "unlimited", run the following AIX ulimit commands from the same shell that runs the backup :
ulimit -d unlimited
ulimit -s unlimited
ulimit -m unlimited
ulimit -n unlimited
Alternatively, to set this permanently, the default or specific user section of the /etc/security/limits file may be updated to set the values to -1 (unlimited). For example :
root:
fsize = -1
core = -1
cpu = -1
data = -1
rss = -1
stack = -1
nofiles = -1
After updating the /etc/security/limits file, it is necessary to re-login for the new values to take effect.
Re-run the backup once the ulimit values have been updated
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Document Information
Modified date:
17 June 2018
UID
swg21690654