Posts Tagged ‘solaris administrator’

Shared Memory Tuning: Startup database – ORA-27102: out of memory Linux-X86_64 Error: 28: No space left on device

May 22nd, 2018, posted in Linux OS, Oracle Queries, Uncategorized
Oracle on linux,Oracle,linux,Oracle DBA,Apps DBA,sun linux 10,sun linux,Oracle Database dba,Oracle database,Oracle Application, Linux, linux, solaris administrator, sun linux,SGA/PGA sizes,solaris SGA/PGA ,linux SGA/PGA sizes, prtconf,ORA-27102,ORA-27101: shared memory realm does not exist,ORA-27101,shared memory realm does not exist,SVR4 Error: 2: No such file or directory,Oracle Linux,Linux Oracle 
SQL> startup
ORA-27102: out of memory
Linux-x86_64 Error: 28: No space left on device
I have used RHEL X86_64 + memory (32GB) and setted sga_max_size=20G + sga_target=20G and …
$ cat /proc/sys/kernel/shmmax
What wrong with my kernel tuning… So, I checked metalink (301830.1) and some recommend from RHEL
They told; set SHMALL to the total amount of physical RAM divided by page size.

SHMALL =>Total amount of shared memory available (bytes or pages)

Check Page Size:
$ getconf PAGE_SIZE
Determine the system wide maximum number of shared memory pages:
$ cat /proc/sys/kernel/shmall
My system 64bits with memory 32GB, then 1024 * 1024 * 1024 * 32 / 4096 = 8388608
So, change kernel.shmall = 8388608
$ su - root
# echo 8388608 > /proc/sys/kernel/shmall
Or modify /etc/sysctl.conf file:
# sysctl -p
After changed… check and startup database again:
$ cat /proc/sys/kernel/shmall
SQL> startup




--- NO ERROR ---
From this idea with memory 32GB
mem=$(free|grep Mem|awk '{print$2}')
totmem=$(echo "$mem*1024"|bc)
huge=$(grep Hugepagesize /proc/meminfo|awk '{print $2}')
max=$(echo "$totmem*75/100"|bc)
all=$(echo "$max/$huge"|bc)
echo "kernel.shmmax = $max"
echo "kernel.shmall = $all"
kernel.shmmax = 25213120512, kernel.shmall = 12311094
However, This case “ORA-27102: out of memory Linux-X86_64 Error: 28: No space left on device” , solved by set SHMALL = MemTotal(byte)/PAGE_SIZE
and …
I hope to hear your idea about kernel tuning with Oracle Database.

Tar: .file too large to archive. Use E function modifier

April 30th, 2018, posted in Solaris

Tar, .file too large to archive, Use E function modifier,E function modifier,solaris 10,unix,linux,sun solaris 10,solaris administrator,Using TAR for big files

tar: .file too large to archive. Use E function modifier.

Using TAR for big files ( > 8GB)

In Unix environment, If you are trying to “tar” OS files that is bigger than 8 GB of size. Following error is observed.

Regular tar command:

tar -cvf test.dmp.tar test.dmp


tar: test.dmp too large to archive.  Use E function modifier.


tar -cvEf test.dmp.tar test.dmp

Fixing the ORA-27102: out of memory Error in Oracle on Solaris 10

April 8th, 2018, posted in Oracle Queries, Solaris


As part of a database tuning effort you increase the SGA/PGA sizes; and Oracle greets with anORA-27102: out of memoryerror message. The system had enough free memory to serve the needs of Oracle.

SQL> startup
ORA-27102: out of memory
SVR4 Error: 22: Invalid argument


$ oerr ORA 27102
27102, 00000, "out of memory"
// \*Cause: Out of memory
// \*Action: Consult the trace file for details


Not so helpful. Let’s look the alert log for some clues.


% tail -2 alert.log
WARNING: EINVAL creating segment of size 0x000000028a006000
fix shm parameters in /etc/system or equivalent


Oracle is trying to create a 10G shared memory segment (depends on SGA/PGA sizes), but operating system (Solaris in this example) responded with an invalid argument (EINVAL) error message. There is a little hint about setting shm parameters in/etc/system.

Prior to Solaris 10,shmsys:shminfo_shmmaxparameter has to be set in/etc/systemwith maximum memory segment value that can be created. 8M is the default value on Solaris 9 and prior versions; where as 1/4th of the physical memory is the default on Solaris 10 and later. On a Solaris 10 (or later) system, it can be verified as shown below:


% prtconf | grep Mem
Memory size: 32760 Megabytes
% id -p
uid=59008(oracle) gid=10001(dba) projid=3(default)
% prctl -n project.max-shm-memory -i project 3
project: 3: default
NAME    PRIVILEGE       VALUE    FLAG   ACTION                       RECIPIENT
        privileged      7.84GB      -   deny                                 -
        system          16.0EB    max   deny                                 -


Now it is clear that the system is using the default value of 8G in this scenario, where as the application (Oracle) is trying to create a memory segment (10G) larger than 8G. Hence the failure.

So, the solution is to configure the system with a value large enough for the shared segment being created, so Oracle succeeds in starting up the database instance.

On Solaris 9 and prior releases, it can be done by adding the following line to/etc/system, followed by a reboot for the system to pick up the new value.

set shminfo_shmmax = 0x000000028a006000Howevershminfo_shmmaxparameter was obsoleted with the release of Solaris 10; and Sun doesn’t recommend setting this parameter in/etc/systemeven though it works as expected.

On Solaris 10 and later, this value can be changed dynamically on a per project basis with the help of resource control facilities . This is how we do it on Solaris 10 and later:


% prctl -n project.max-shm-memory -r -v 10G -i project 3
% prctl -n project.max-shm-memory -i project 3
project: 3: default
NAME    PRIVILEGE       VALUE    FLAG   ACTION                       RECIPIENT
        privileged      10.0GB      -   deny                                 -
        system          16.0EB    max   deny                                 -


Note that changes made with theprctlcommand on a running system are temporary, and will be lost when the system is rebooted. To make the changes permanent, create a project withprojaddcommand and associate it with the user account as shown below:


% projadd -p 3  -c 'eBS benchmark' -U oracle -G dba  -K 'project.max-shm-memory=(privileged,10G,deny)' OASB
% usermod -K project=OASB oracle


Finally make sure the project is created withprojects -lorcat /etc/projectcommands.


% projects -l
        projid : 3
        comment: "eBS benchmark"
        users  : oracle
        groups : dba
        attribs: project.max-shm-memory=(privileged,10737418240,deny)
% cat /etc/project
OASB:3:eBS benchmark:oracle:dba:project.max-shm-memory=(privileged,10737418240,deny)


With these changes, Oracle would start the database up normally.


SQL> startup
ORACLE instance started.
Total System Global Area 1.0905E+10 bytes
Fixed Size                  1316080 bytes
Variable Size            4429966096 bytes
Database Buffers         6442450944 bytes
Redo Buffers               31457280 bytes
Database mounted.
Database opened.



Addendum : Oracle RAC settings

Anonymous Bob suggested the following settings for Oracle RAC in the form of a comment for the benefit of others who run into similar issue(s) when running Oracle RAC. I’m pasting the comment as is (Disclaimer: I have not verified these settings):

Thanks for a great explanation, I would like to add one comment that will help those with an Oracle RAC installation. Modifying the default project covers oracle processes great and is all that is needed for a single instance DB. In RAC however, the CRS process starts the DB and it is a root owned process and root does not use the default project. To fix ORA-27102 issue for RAC I added the following lines to an init script that runs before the script fires.


# Recommended Oracle RAC system params
ndd -set /dev/udp udp_xmit_hiwat 65536
ndd -set /dev/udp udp_recv_hiwat 65536
# For root processes like crsd
prctl -n project.max-shm-memory -r -v 8G -i project system
prctl -n project.max-shm-ids -r -v 512 -i project system
# For oracle processes like sqlplus
prctl -n project.max-shm-memory -r -v 8G -i project default
prctl -n project.max-shm-ids -r -v 512 -i project default

So simple yet it took me a week working with Oracle and SUN to come up with that answer…Hope that helps someone out.