Pre-Installation Configuration
Before installing SQreamDB, it is essential that you tune your system for better performance and stability.
BIOS Settings
The first step when setting your pre-installation configurations is to use the BIOS settings.
The BIOS settings may have a variety of names, or may not exist on your system. Each system vendor has a different set of settings and variables. It is safe to skip any and all of the configuration steps, but this may impact performance.
If any doubt arises, consult the documentation for your server or your hardware vendor for the correct way to apply the settings.
Item |
Setting |
Rationale |
---|---|---|
Management console access |
Connected |
Connection to OOB required to preserve continuous network uptime. |
All drives |
Connected and displayed on RAID interface |
Prerequisite for cluster or OS installation. |
RAID volumes. |
Configured according to project guidelines. Must be rebooted to take effect. |
Clustered to increase logical volume and provide redundancy. |
Fan speed Thermal Configuration. |
Dell fan speed: High Maximum. Specified minimum setting: 60. HPe thermal configuration: Increased cooling. |
NVIDIA Tesla GPUs are passively cooled and require high airflow to operate at full performance. |
Power regulator or iDRAC power unit policy |
HPe: HP static high performance mode enabled. Dell: iDRAC power unit policy (power cap policy) disabled. |
Other power profiles (such as “balanced”) throttle the CPU and diminishes performance. Throttling may also cause GPU failure. |
System Profile, Power Profile, or Performance Profile |
High Performance |
The Performance profile provides potentially increased performance by maximizing processor frequency, and the disabling certain power saving features such as C-states. Use this setting for environments that are not sensitive to power consumption. |
Power Cap Policy or Dynamic power capping |
Disabled |
Other power profiles (like “balanced”) throttle the CPU and may diminish performance or cause GPU failure. This setting may appear together with the above (Power profile or Power regulator). This setting allows disabling system ROM power calibration during the boot process. Power regulator settings are named differently in BIOS and iLO/iDRAC. |
Intel Turbo Boost |
Enabled |
Intel Turbo Boost enables overclocking the processor to boost CPU-bound operation performance. Overclocking may risk computational jitter due to changes in the processor’s turbo frequency. This causes brief pauses in processor operation, introducing uncertainty into application processing time. Turbo operation is a function of power consumption, processor temperature, and the number of active cores. |
Intel Virtualization Technology (VT-d) |
Disable |
VT-d is optimal for running VMs. However, when running Linux natively, disabling VT-d boosts performance by up to 10%. |
Logical Processor |
HPe: Enable Hyperthreading Dell: Enable Logical Processor |
Hyperthreading doubles the amount of logical processors, which may improve performance by ~5-10% for CPU-bound operations. |
Intel Virtualization Technology (VT-d) |
Disable |
VT-d is optimal for running VMs. However, when running Linux natively, disabling VT-d boosts performance by up to 10%. |
Processor C-States (Minimum processor idle power core state) |
Disable |
Processor C-States reduce server power when the system is in an idle state. This causes slower cold-starts when the system transitions from an idle to a load state, and may reduce query performance by up to 15%. |
HPe: Energy/Performance bias |
Maximum performance |
Configures processor sub-systems for high-performance and low-latency. Other power profiles (like “balanced”) throttle the CPU and may diminish performance. Use this setting for environments that are not sensitive to power consumption. |
HPe: DIMM voltage |
Optimized for Performance |
Setting a higher voltage for DIMMs may increase performance. |
Memory Operating Mode |
Optimizer Mode, Disable Node Interleaving, Auto Memory Operating Voltage |
Memory Operating Mode is tuned for performance in Optimizer mode. Other modes may improve reliability, but reduce performance. Node Interleaving should be disabled because enabling it interleaves the memory between memory nodes, which harms NUMA-aware applications such as SQream DB. |
HPe: Memory power savings mode |
Maximum performance |
This setting configures several memory parameters to optimize the performance of memory sub-systems. The default setting is Balanced. |
HPe ACPI SLIT |
Enabled |
ACPI SLIT sets the relative access times between processors and memory and I/O sub-systems. ACPI SLIT enables operating systems to use this data to improve performance by more efficiently allocating resources and workloads. |
QPI Snoop |
Cluster on Die or Home Snoop |
QPI (QuickPath Interconnect) Snoop lets you configure different Snoop modes that impact the QPI interconnect. Changing this setting may improve the performance of certain workloads. The default setting of Home Snoop provides high memory bandwidth in an average NUMA environment. Cluster on Die may provide increased memory bandwidth in highly optimized NUMA workloads. Early Snoop may decrease memory latency, but may result in lower overall bandwidth compared to other modes. |
Installing the Operating System
Once the BIOS settings have been set, you must install the operating system. Either the CentOS (versions 7.6-7.9) or RHEL (versions 7.6-7.9) must be installed before installing the SQream database, by either the customer or a SQream representative.
To install the operating system:
Select a language (English recommended).
From Software Selection, select Minimal.
Select the Development Tools group checkbox.
Continue the installation.
Set up the necessary drives and users as per the installation process.
Using Debugging Tools is recommended for future problem-solving if necessary.
Selecting the Development Tools group installs the following tools:
autoconf
automake
binutils
bison
flex
gcc
gcc-c++
gettext
libtool
make
patch
pkgconfig
redhat-rpm-config
rpm-build
rpm-sign
The root user is created and the OS shell is booted up.
Configuring the Operating System
Once you’ve installted your operation system, you can configure it. When configuring the operating system, several basic settings related to creating a new server are required. Configuring these as part of your basic set-up increases your server’s security and usability.
Logging In to the Server
You can log in to the server using the server’s IP address and password for the root user. The server’s IP address and root user were created while installing the operating system above.
Automatically Creating a SQream User
To automatically create a SQream user:
If a SQream user was created during installation, verify that the same ID is used on every server:
$ sudo id sqream
The ID 1000 is used on each server in the following example:
$ uid=1000(sqream) gid=1000(sqream) groups=1000(sqream)
If the ID’s are different, delete the SQream user and SQream group from both servers:
$ sudo userdel sqream
Recreate it using the same ID:
$ sudo rm /var/spool/mail/sqream
Manually Creating a SQream User
To manually create a SQream user:
SQream enables you to manually create users. This section shows you how to manually create a user with the UID 1111. You cannot manually create during the operating system installation procedure.
Add a user with an identical UID on all cluster nodes:
$ useradd -u 1111 sqream
Add the user sqream to the wheel group.
$ sudo usermod -aG wheel sqream
You can remove the SQream user from the wheel group when the installation and configuration are complete:
$ passwd sqream
Log out and log back in as sqream.
Note
If you deleted the sqream user and recreated it with different ID, to avoid permission errors, you must change its ownership to /home/sqream.
Change the sqream user’s ownership to /home/sqream:
$ sudo chown -R sqream:sqream /home/sqream
Setting Up A Locale
SQream enables you to set up a locale. In this example, the locale used is your own location.
To set up a locale:
Set the language of the locale:
$ sudo localectl set-locale LANG=en_US.UTF-8
Set the time stamp (time and date) of the locale:
$ sudo timedatectl set-timezone Asia/Jerusalem
If needed, you can run the timedatectl list-timezones command to see your current time-zone.
Installing the Required Packages
You can install the required packages by running the following command:
$ sudo yum install ntp pciutils monit zlib-devel openssl-devel kernel-devel-$(uname -r) kernel-headers-$(uname -r) gcc net-tools wget jq
Installing the Recommended Tools
You can install the recommended tools by running the following command:
$ sudo yum install bash-completion.noarch vim-enhanced vim-common net-tools iotop htop psmisc screen xfsprogs wget yum-utils deltarpm dos2unix
Installing Python 3.6.7
Download the Python 3.6.7 source code tarball file from the following URL into the /home/sqream directory:
$ wget https://www.python.org/ftp/python/3.6.7/Python-3.6.7.tar.xz
Extract the Python 3.6.7 source code into your current directory:
$ tar -xf Python-3.6.7.tar.xz
Navigate to the Python 3.6.7 directory:
$ cd Python-3.6.7
Run the ./configure script:
$ ./configure
Build the software:
$ make -j30
Install the software:
$ sudo make install
Verify that Python 3.6.7 has been installed:
$ python3
Installing NodeJS on CentOS
To install the node.js on CentOS:
Download the setup_12.x file as a root user logged in shell:
$ curl -sL https://rpm.nodesource.com/setup_12.x | sudo bash -
Clear the YUM cache and update the local metadata:
$ sudo yum clean all && sudo yum makecache fast
Install the node.js file:
$ sudo yum install -y nodejs
Install npm and make it available for all users:
$ sudo npm install pm2 -g
Installing NodeJS on Ubuntu
To install the node.js file on Ubuntu:
Download the setup_12.x file as a root user logged in shell:
$ curl -sL https://rpm.nodesource.com/setup_12.x | sudo bash -
Install the node.js file:
$ sudo apt-get install -y nodejs
Install npm and make it available for all users:
$ sudo npm install pm2 -g
Installing NodeJS Offline
To install NodeJS Offline
Download the NodeJS source code tarball file from the following URL into the /home/sqream directory:
$ wget https://nodejs.org/dist/v12.13.0/node-v12.13.0-linux-x64.tar.xz
Move the node-v12.13.0-linux-x64 file to the /usr/local directory.
$ sudo mv node-v12.13.0-linux-x64 /usr/local
Navigate to the /usr/bin/ directory:
$ cd /usr/bin
Create a symbolic link to the /local/node-v12.13.0-linux-x64/bin/node node directory:
$ sudo ln -s ../local/node-v12.13.0-linux-x64/bin/node node
Create a symbolic link to the /local/node-v12.13.0-linux-x64/bin/npm npm directory:
$ sudo ln -s ../local/node-v12.13.0-linux-x64/bin/npm npm
Create a symbolic link to the /local/node-v12.13.0-linux-x64/bin/npx npx directory:
$ sudo ln -s ../local/node-v12.13.0-linux-x64/bin/npx npx
Verify that the node versions for the above are correct:
$ node --version
Installing the pm2 Service Offline
To install the pm2 Service Offline
On a machine with internet access, install the following:
nodejs
npm
pm2
Extract the pm2 module to the correct directory:
$ cd /usr/local/node-v12.13.0-linux-x64/lib/node_modules $ tar -czvf pm2_x86.tar.gz pm2
Copy the pm2_x86.tar.gz file to a server without access to the internet and extract it.
Move the pm2 folder to the /usr/local/node-v12.13.0-linux-x64/lib/node_modules directory:
$ sudo mv pm2 /usr/local/node-v12.13.0-linux-x64/lib/node_modules
Navigate back to the /usr/bin directory:
$ cd /usr/bin again
Create a symbolink to the pm2 service:
$ sudo ln -s /usr/local/node-v12.22.3-linux-x64/lib/node_modules/pm2/bin/pm2 pm2
Verify that installation was successful:
$ pm2 list
Note
This must be done as a sqream user, and not as a sudo user.
Verify that the node version is correct:
$ node -v
Configuring the Network Time Protocol
This section describes how to configure your Network Time Protocol (NTP).
If you don’t have internet access, see Configure NTP Client to Synchronize with NTP Server.
To configure your NTP:
Install the NTP file.
$ sudo yum install ntp
Enable the ntpd program.
$ sudo systemctl enable ntpd
Start the ntdp program.
$ sudo systemctl start ntpd
Print a list of peers known to the server and a summary of their states.
$ sudo ntpq -p
Configuring the Network Time Protocol Server
If your organization has an NTP server, you can configure it.
To configure your NTP server:
Output your NTP server address and append
/etc/ntpd.conf
to the outuput.$ echo -e "\nserver <your NTP server address>\n" | sudo tee -a /etc/ntp.conf
Restart the service.
$ sudo systemctl restart ntpd
Check that synchronization is enabled:
$ sudo timedatectl
Checking that synchronization is enabled generates the following output:
$ Local time: Sat 2019-10-12 17:26:13 EDT Universal time: Sat 2019-10-12 21:26:13 UTC RTC time: Sat 2019-10-12 21:26:13 Time zone: America/New_York (EDT, -0400) NTP enabled: yes NTP synchronized: yes RTC in local TZ: no DST active: yes Last DST change: DST began at Sun 2019-03-10 01:59:59 EST Sun 2019-03-10 03:00:00 EDT Next DST change: DST ends (the clock jumps one hour backwards) at Sun 2019-11-03 01:59:59 EDT Sun 2019-11-03 01:00:00 EST
Configuring the Server to Boot Without the UI
You can configure your server to boot without a UI in cases when it is not required (recommended) by running the following command:
$ sudo systemctl set-default multi-user.target
Running this command activates the NO-UI server mode.
Configuring the Security Limits
The security limits refers to the number of open files, processes, etc.
You can configure the security limits by running the echo -e command as a root user logged in shell:
$ sudo bash
$ echo -e "sqream soft nproc 1000000\nsqream hard nproc 1000000\nsqream soft nofile 1000000\nsqream hard nofile 1000000\nsqream soft core unlimited\nsqream hard core unlimited" >> /etc/security/limits.conf
Configuring the Kernel Parameters
To configure the kernel parameters:
Insert a new line after each kernel parameter:
$ echo -e "vm.dirty_background_ratio = 5 \n vm.dirty_ratio = 10 \n vm.swappiness = 10 \n vm.vfs_cache_pressure = 200 \n vm.zone_reclaim_mode = 0 \n" >> /etc/sysctl.conf
Note
In the past, the vm.zone_reclaim_mode parameter was set to 7. In the latest Sqream version, the vm.zone_reclaim_mode parameter must be set to 0. If it is not set to 0, when a numa node runs out of memory, the system will get stuck and will be unable to pull memory from other numa nodes.
Check the maximum value of the fs.file.
$ sysctl -n fs.file-max
If the maximum value of the fs.file is smaller than 2097152, run the following command:
$ echo "fs.file-max=2097152" >> /etc/sysctl.conf
Run the following command:
$ sudo echo “net.ipv4.ip_forward = 1” >> /etc/sysctl.conf
Reboot your system:
$ sudo reboot
Configuring the Firewall
The example in this section shows the open ports for four sqreamd sessions. If more than four are required, open the required ports as needed. Port 8080 in the example below is a new UI port.
To configure the firewall:
Start the service and enable FirewallID on boot:
$ systemctl start firewalld
Add the following ports to the permanent firewall:
$ firewall-cmd --zone=public --permanent --add-port=8080/tcp $ firewall-cmd --zone=public --permanent --add-port=3105/tcp $ firewall-cmd --zone=public --permanent --add-port=3108/tcp $ firewall-cmd --zone=public --permanent --add-port=5000-5003/tcp $ firewall-cmd --zone=public --permanent --add-port=5100-5103/tcp $ firewall-cmd --permanent --list-all
Reload the firewall:
$ firewall-cmd --reload
Enable FirewallID on boot:
$ systemctl enable firewalld
If you do not need the firewall, you can disable it:
$ sudo systemctl disable firewalld
Disabling selinux
To disable selinux:
Show the status of selinux:
$ sudo sestatus
If the output is not disabled, edit the /etc/selinux/config file:
$ sudo vim /etc/selinux/config
Change SELINUX=enforcing to SELINUX=disabled.
The above changes will only take effect after rebooting the server.
You can disable selinux immediately after rebooting the server by running the following command:
$ sudo setenforce 0
Configuring the /etc/hosts File
To configure the /etc/hosts file:
Edit the /etc/hosts file:
$ sudo vim /etc/hosts
Call your local host:
$ 127.0.0.1 localhost $ <server1 ip> <server_name> $ <server2 ip> <server_name>
Configuring the DNS
To configure the DNS:
Run the ifconfig commasnd to check your NIC name. In the following example, eth0 is the NIC name:
$ sudo vim /etc/sysconfig/network-scripts/ifcfg-eth0
Replace the DNS lines from the example above with your own DNS addresses :
$ DNS1="4.4.4.4" $ DNS2="8.8.8.8"
Installing the Nvidia CUDA Driver
After configuring your operating system, you must install the Nvidia CUDA driver.
Warning
If your UI runs on the server, the server must be stopped before installing the CUDA drivers.
CUDA Driver Prerequisites
Verify that the NVIDIA card has been installed and is detected by the system:
$ lspci | grep -i nvidia
Check which version of gcc has been installed:
$ gcc --version
If gcc has not been installed, install it for one of the following operating systems:
On RHEL/CentOS:
$ sudo yum install -y gcc
On Ubuntu:
$ sudo apt-get install gcc
Updating the Kernel Headers
To update the kernel headers:
Update the kernel headers on one of the following operating systems:
On RHEL/CentOS:
$ sudo yum install kernel-devel-$(uname -r) kernel-headers-$(uname -r)
On Ubuntu:
$ sudo apt-get install linux-headers-$(uname -r)
Install wget one of the following operating systems:
On RHEL/CentOS:
$ sudo yum install wget
On Ubuntu:
$ sudo apt-get install wget
Disabling Nouveau
You can disable Nouveau, which is the default driver.
To disable Nouveau:
Check if the Nouveau driver has been loaded:
$ lsmod | grep nouveau
If the Nouveau driver has been loaded, the command above generates output.
Blacklist the Nouveau drivers to disable them:
$ cat <<EOF | sudo tee /etc/modprobe.d/blacklist-nouveau.conf blacklist nouveau options nouveau modeset=0 EOF
Regenerate the kernel initramfs directory set:
Modify the initramfs directory set:
$ sudo dracut --forceReboot the server:
$ sudo reboot
Installing the CUDA Driver
This section describes how to install the CUDA driver.
Note
The version of the driver installed on the customer’s server must be equal or higher than the driver included in the Sqream release package. Contact a Sqream customer service representative to identify the correct version to install.
The Installing the CUDA Driver section describes the following:
Installing the CUDA Driver from the Repository
Installing the CUDA driver from the Repository is the recommended installation method.
Warning
For A100 GPU and other A series GPUs, you must install the cuda 11.4.3 driver. The version of the driver installed on the customer server must be equal to or higher than the one used to build the SQream package. For questions related to which driver to install, contact SQream Customer Support.
To install the CUDA driver from the Repository:
Install the CUDA dependencies for one of the following operating systems:
For RHEL:
$ sudo rpm -Uvh http://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
For CentOS:
$ sudo yum install epel-release
Install the CUDA dependencies from the epel repository:
$ sudo yum install dkms libvdpau
Installing the CUDA depedendencies from the epel repository is only required for installing runfile.
Download and install the required local repository:
Intel - CUDA 10.1 for RHEL7:
$ wget http://developer.download.nvidia.com/compute/cuda/10.1/Prod/local_installers/cuda-repo-rhel7-10-1-local-10.1.243-418.87.00-1.0-1.x86_64.rpm $ sudo yum localinstall cuda-repo-rhel7-10-1-local-10.1.243-418.87.00-1.0-1.x86_64.rpm
Intel - 11.4.3 repository:
$ wget https://developer.download.nvidia.com/compute/cuda/11.4.3/local_installers/cuda-repo-rhel7-11-4-local-11.4.3_470.82.01-1.x86_64.rpm $ sudo yum localinstall cuda-repo-rhel7-11-4-local-11.4.3_470.82.01-1.x86_64.rpm
IBM Power9 - CUDA 10.1 for RHEL7:
$ wget https://developer.download.nvidia.com/compute/cuda/10.1/Prod/local_installers/cuda-repo-rhel7-10-1-local-10.1.243-418.87.00-1.0-1.ppc64le.rpm $ sudo yum localinstall cuda-repo-rhel7-10-1-local-10.1.243-418.87.00-1.0-1.ppc64le.rpm
Install the CUDA drivers:
Clear the YUM cache:
$ sudo yum clean all
Install the most current DKMS (Dynamic Kernel Module Support) NVIDIA driver:
$ sudo yum -y install nvidia-driver-latest-dkms
Verify that the installation was successful:
$ nvidia-smi
Note
If you do not have access to internet, you can set up a local repository offline.
You can prepare the CUDA driver offline from a server connected to the CUDA repo by running the following commands as a root user:
Query all the packages installed in your system, and verify that cuda-repo has been installed:
$ rpm -qa |grep cuda-repo
Navigate to the correct repository:
$ cd /etc/yum.repos.d/
List in long format and print lines matching a pattern for the cuda file:
$ ls -l |grep cuda
The following is an example of the correct output:
$ cuda-10-1-local.repo
Edit the /etc/yum.repos.d/cuda-10-1-local.repo file:
$ vim /etc/yum.repos.d/cuda-10-1-local.repo
The following is an example of the correct output:
$ name=cuda-10-1-local
Clone the repository to a location where it can be copied from:
$ reposync -g -l -m --repoid=cuda-10-1-local --download_path=/var/cuda-repo-10.1-local
Copy the repository to the installation server and create the repository:
$ createrepo -g comps.xml /var/cuda-repo-10.1-local
Add a repo configuration file in /etc/yum.repos.d/ by editing the /etc/yum.repos.d/cuda-10.1-local.repo repository:
$ [cuda-10.1-local] $ name=cuda-10.1-local $ baseurl=file:///var/cuda-repo-10.1-local $ enabled=1 $ gpgcheck=1 $ gpgkey=file:///var/cuda-repo-10-1-local/7fa2af80.pub
Install the CUDA drivers by installing the most current DKMS (Dynamic Kernel Module Support) NVIDIA driver as a root user logged in shell:
$ sudo yum -y install nvidia-driver-latest-dkms
Tuning Up NVIDIA Performance
This section describes how to tune up NVIDIA performance.
Note
The procedures in this section are relevant to Intel only.
To Tune Up NVIDIA Performance when Driver Installed from the Repository
To tune up NVIDIA performance when the driver was installed from the repository:
Check the service status:
$ sudo systemctl status nvidia-persistenced
If the service exists, it will be stopped be default.
Start the service:
$ sudo systemctl start nvidia-persistenced
Verify that no errors have occurred:
$ sudo systemctl status nvidia-persistenced
Enable the service to start up on boot:
$ sudo systemctl enable nvidia-persistenced
For H100/A100, add the following lines:
$ nvidia-persistenced
Note
The following are mandatory for IBM:
$ sudo systemctl start nvidia-persistenced $ sudo systemctl enable nvidia-persistenced
Reboot the server and run the NVIDIA System Management Interface (NVIDIA SMI):
$ nvidia-smi
Note
Setting up the NVIDIA POWER9 CUDA driver includes additional set-up requirements. The NVIDIA POWER9 CUDA driver will not function properly if the additional set-up requirements are not followed. See POWER9 Setup for the additional set-up requirements.
To Tune Up NVIDIA Performance when Driver Installed from the Runfile
To tune up NVIDIA performance when the driver was installed from the runfile:
Change the permissions on the rc.local file to executable:
$ sudo chmod +x /etc/rc.local
Edit the /etc/yum.repos.d/cuda-10-1-local.repo file:
$ sudo vim /etc/rc.local
Add the following lines:
For H100/A100:
$ nvidia-persistenced
For IBM (mandatory):
$ sudo systemctl start nvidia-persistenced $ sudo systemctl enable nvidia-persistenced
For K80:
$ nvidia-persistenced $ nvidia-smi -pm 1 $ nvidia-smi -acp 0 $ nvidia-smi --auto-boost-permission=0 $ nvidia-smi --auto-boost-default=0
Reboot the server and run the NVIDIA System Management Interface (NVIDIA SMI):
$ nvidia-smi
Note
Setting up the NVIDIA POWER9 CUDA driver includes additional set-up requirements. The NVIDIA POWER9 CUDA driver will not function properly if the additional set-up requirements are not followed. See POWER9 Setup for the additional set-up requirements.
Disabling Automatic Bug Reporting Tools
To disable automatic bug reporting tools:
Run the following abort commands:
$ for i in abrt-ccpp.service abrtd.service abrt-oops.service abrt-pstoreoops.service abrt-vmcore.service abrt-xorg.service ; do sudo systemctl disable $i; sudo systemctl stop $i; done
The server is ready for the SQream software installation.
Run the following checks:
Check the OS release:
$ cat /etc/os-release
Verify that a SQream user exists and has the same ID on all cluster member services:
$ id sqream
Verify that the storage is mounted:
$ mount
Verify that the driver has been installed correctly:
$ nvidia-smi
Check the maximum value of the fs.file:
$ sysctl -n fs.file-max
Run the following command as a SQream user:
$ ulimit -c -u -n
The following shows the desired output:
$ core file size (blocks, -c) unlimited $ max user processes (-u) 1000000 $ open files (-n) 1000000
Enabling Core Dumps
After installing the Nvidia CUDA driver, you can enable your core dumps. While SQream recommends enabling your core dumps, it is optional.
The Enabling Core Dumps section describes the following:
Checking the abrtd Status
To check the abrtd status:
Check if abrtd is running:
$ sudo ps -ef |grep abrt
If abrtd is running, stop it:
$ sudo service abrtd stop $ sudo chkconfig abrt-ccpp off $ sudo chkconfig abrt-oops off $ sudo chkconfig abrt-vmcore off $ sudo chkconfig abrt-xorg off $ sudo chkconfig abrtd off
Setting the Limits
To set the limits:
Set the limits:
$ ulimit -c
If the output is 0, add the following lines to the limits.conf file (/etc/security):
$ * soft core unlimited $ * hard core unlimited
Log out and log in to apply the limit changes.
Creating the Core Dumps Directory
To set the core dumps directory:
Make the /tmp/core_dumps directory:
$ mkdir /tmp/core_dumps
Set the ownership of the /tmp/core_dumps directory:
$ sudo chown sqream.sqream /tmp/core_dumps
Grant read, write, and execute permissions to all users:
$ sudo chmod -R 777 /tmp/core_dumps
Warning
Because the core dump file may be the size of total RAM on the server, verify that you have sufficient disk space. In the example above, the core dump is configured to the /tmp/core_dumps directory. You must replace path according to your own environment and disk space.
Setting the Output Directory of the /etc/sysctl.conf File
To set the output directory of the /etc/sysctl.conf file:
Edit the /etc/sysctl.conf file:
$ sudo vim /etc/sysctl.conf
Add the following to the bottom of the file:
$ kernel.core_uses_pid = 1 $ kernel.core_pattern = /<tmp/core_dumps>/core-%e-%s-%u-%g-%p-%t $ fs.suid_dumpable = 2
To apply the changes without rebooting the server, run the following:
$ sudo sysctl -p
Check that the core output directory points to the following:
$ sudo cat /proc/sys/kernel/core_patternThe following shows the correct generated output:
$ /tmp/core_dumps/core-%e-%s-%u-%g-%p-%t
Verify that the core dumping works:
$ select abort_server();
Verifying that the Core Dumps Work
You can verify that the core dumps work only after installing and running SQream. This causes the server to crash and a new core.xxx file to be included in the folder that is written in /etc/sysctl.conf
To verify that the core dumps work:
Stop and restart all SQream services.
Connect to SQream with ClientCmd and run the following command:
$ select abort_server();
Troubleshooting Core Dumping
This section describes the troubleshooting procedure to be followed if all parameters have been configured correctly, but the cores have not been created.
To troubleshoot core dumping:
Reboot the server.
Verify that you have folder permissions:
$ sudo chmod -R 777 /tmp/core_dumps
Verify that the limits have been set correctly:
$ ulimit -c
If all parameters have been configured correctly, the correct output is:
$ core file size (blocks, -c) unlimited $ open files (-n) 1000000
If all parameters have been configured correctly, but running ulimit -c outputs 0, run the following:
$ sudo vim /etc/profile
Search for line and tag it with the hash symbol:
$ ulimit -S -c 0 > /dev/null 2>&1
Log out and log in.
Run the ulimit -c command:
$ ulimit -c command
If the line is not found in /etc/profile directory, do the following:
Run the following command:
$ sudo vim /etc/init.d/functions
Search for the following:
$ ulimit -S -c ${DAEMON_COREFILE_LIMIT:-0} >/dev/null 2>&1
If the line is found, tag it with the hash symbol and reboot the server.