asr.tech.notes

While mounting NFS share from EMC celerra (NX80G v5.6) which has file system level quota on the NAS, the client sees the size of the entire file system on NAS and not the quota. This is very misleading on the client side where the users assume there are a lot space available on the system than it is (from the df command). To fix this issue, the following parameter on the NAS needs to be enabled to show the quota size instead of file system size: # server_param <server_name> -f quota –modify useQuotaInFsStat –value 1 Display current value: # server_param <server_name> -f quota –I useQuotaInFsStat  

Check if a module is installed: perl -M<module name>-e 1 Check the version of the installed modules: perl -M<module name> -e 'print "$<module name>::VERSION \n"' Install a perl module using CPAN: perl -MCPAN -e 'install <module name>' ________________________________________________ References: http://www.perlhowto.com/perl_modules http://www.cpan.org/misc/cpan-faq.html#How_install_Perl_modules

/usr/sbin/mknfsmnt -f '[local directory] ' -d '[remote directory] ' -h ' ' -M 'sys' '-B' '-A' -t 'rw' -w 'bg' -b '32768' -c '32768' -K '3' -k 'tcp' '-Y' '-Z' '-X' '-S' '-j' -R '5' '-q' '-g' The values used are as per oracle database requirement [ FROM AIX INFO CENTER ] -A The /etc/filesystems entry for this file system specifies that it should be automatically mounted at system restart. -a The /etc/filesystems entry for this file system specifies that it should not be automatically mounted at system restart. This is the default flag. -B Adds an entry to the /etc/filesystems file and attempts to mount the file system. This is the default flag. -b ReadBufferSize Indicates the size of the read buffer in bytes specified by the ReadBufferSize variable. -c WriteBufferSize Indicates the size of the wri...

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The following are the few commands I used heavily for troubleshooting a performance Issue on the AIX servers: 1. tprof: tprof -kes -x sleep 60 This will collect tprof data for 60 seconds and will store it in a file called sleep.prof 2. Collecting data for SPLAT: splat command uses the output create by the trace command to analyze the lock performance on the system where you have multi-threaded applications running. a. Collect trace data: generate gensyms data gensyms > gensyms.out trace -aC all -o trace -3; sleep 60 ; trcstop This will collect trace data for 60 seconds and will generate files starting with trace, trace-1 etc depending on the number of virtual cpus. b. run splat command to analyze the lock performance: splat -sa -da -S100 -i trace -n gensyms.out -o splat.out The final analysis of the lock performance can be found in splat.out. There are various options available for the above commands and also documents in AIX information center on how to inter...

Commands to restart RMC connection (to HMC from LPAR) It has become very common with the IBM HMC to LPAR (logical/micro partition) communication to drop for unknown reasons.  Most of the time this is not a problem unless there is a need to do a dynamic logical partition operation (or DLAPR operation to add/remove resources on the fly).  This will become evident during the DLPAR operation when HMC complains about having no RMC connection to LPAR in operation.  When this happens run the following commands on the LPAR in question before reattemping the operation.  The DLPAR operation will still work with out this connection, but the LPAR needs a restart to see the change in the resources.  Restart the RMC connection on the LPAR: # /usr/sbin/rsct/install/bin/recfgct # /usr/sbin/rsct/bin/rmcctrl -p Verify the connection by running: lsrsrc IBM.ManagementServer This will show the HMC IP/hostname and the LPAR information.

RAM disk in AIX AIX provides 'mkramdisk' command for producing a disk that resides in the RAM for very high I/O intensive applications like database. Here is a simple set of commands to create a ramdisk and a filesystem on top of it: create a RAM disk specifying the size          # mkramdisk 5G The system will assign the available RAM disk.  Since this is the first one, it will be called as ramdisk0 Check for the new disk         # ls -l /dev | grep -i ram If there isn't sufficient available memory, the mkramdisk command will warn about the same during the creation. Create and mount a filesystem on top of the ram disk     # mkfs -V jfs2 -o log=INLINE /dev/ramdisk0     # mkdir -p /ramdisk0     # mount -V jfs2 -o log=INLINE /dev/ramdisk0 /ramdisk0 The new filesystem will now be available like any other FS.   To remove a ram disk, unmount/remove the filesystem and us...