Transaction Log File as a Raw Device (UNIX Only--Not Linux)
The transaction log file can be a raw device rather than an ordinary file system file. A raw device is a disk partition without a file system. This avoids file system overhead for disk input and output. Ingres supports use of a raw device for the transaction log files as a high‑performance option.
By default the install process creates the log file as an ordinary file. After Ingres is installed, you can create and configure the transaction log file as a raw device.
Location of Your Raw Log File (UNIX)
The following restrictions apply to the locations for a raw log file:
• They must be in their own partitions.
• They must not contain a file system.
• They must not be raw devices used by another program.
Create and Configure the Raw Log File (UNIX)
After Ingres is installed, you can create and configure the transaction log file as a raw device.
Note: Check the Readme file for any variations to this procedure that are specific to your platform.
To create and configure a raw log file
1. Log in to your system as the root account.
(If you do not have access to this account, have the UNIX system administrator complete this procedure or log in for you.)
2. Create the raw devices in the locations you have chosen.
For more information about creating a raw device, see the UNIX documentation.
3. Use the ls command to verify that you have two special devices available for each raw location. Enter the following command:
ls -l /dev
This command should return output similar to this example:
crw-r----- 1 root 17, 3 Dec 16 12:52
/dev/rsd1d
brw-r----- 1 root 11, 3 Dec 16 12:52
/dev/sd1d
4. Go to the location of the system files for your instance.
For C shell:
% setenv II_SYSTEM dirname
% set path = ($II_SYSTEM/ingres/{bin,utility} $path)
% cd $II_SYSTEM/ingres
For Bourne shell:
$ II_SYSTEM=dirname
$ export II_SYSTEM
$ PATH=$II_SYSTEM/ingres/utility:$II_SYSTEM/ingres/
bin:$PATH
$ export PATH
$ cd $II_SYSTEM/ingres
5. Issue the following command:
% mkrawlog
The mkrawlog command:
• Requests the full path name of the raw device files.
• Sets Ingres as the owner of all devices.
• Checks that the locations and sizes of the raw devices are valid.
Note: All raw partitions of a multi-partition raw log file must be the same size.
• Sets up file system links to the raw log files in the log subdirectory.
The raw log file is configured.
Last modified date: 08/29/2024