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How to obtain system open file table value in Linux
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ninode(5) File Formats Manual ninode(5) NAME
ninode - maximum number of HFS file system open inodes that can be in memory VALUES
Failsafe Default The default value is computed at runtime and depends on the amount of physical memory on the system. For small memory systems (less than 1GB), the default is 4880. For systems with more than 1GB of memory, the default is 8192, or 8K. Allowed values The minimum value allowed is 14. The maximum value allowed is memory limited. Specify a positive integer value. DESCRIPTION
The tunable defines the number of slots in the HFS inode table. This number limits the number of open inodes that can be in memory for HFS file systems at any given time. The inode table is used as a cache memory. For performance reasons the most recent (number of) open inodes are kept in main memory. The table is hashed. Each unique open file has an open inode associated with it. Therefore, the larger the number of unique open files, the larger should be. Who Is Expected to Change This Tunable? This tunable is only relevant on systems where there are HFS file systems mounted. Note that the use of HFS file systems is being depre- cated in HP-UX. Restrictions on Changing This tunable is static. Any changes to the value of this tunable will require system reboot to take effect. When Should the Value of This Tunable Be Raised? This value of many need to be raised on systems running applications that expect large numbers of open files on HFS file systems. What are the Side Effects of Raising the Value? The HFS inode table is statically allocated, therefore will consume more memory if the value of this tunable is raised. When Should the Value of This Tunable Be Lowered? The value of can be lowered on systems with small or no mounted HFS file systems, to reduce memory consumption. What are the Side Effects of Lowering the Value? The number of open HFS inodes that can be kept in memory is bound to the new lower limit. What Other Tunable Values Should Be Changed at the Same Time? None. WARNINGS
All HP-UX kernel tunable parameters are release specific. This parameter may be removed or have its meaning changed in future releases of HP-UX. The tunable is relevant only on systems with HFS file systems. Note that the use of HFS file systems is being deprecated in HP-UX. This and other HFS related tunable parameters may be removed from future HP-UX releases. Installation of optional kernel software, from HP or other vendors, may cause changes to tunable parameter values. After installation, some tunable parameters may no longer be at the default or recommended values. For information about the effects of installation on tun- able values, consult the documentation for the kernel software being installed. For information about optional kernel software that was factory installed on your system, see at AUTHOR
was developed by HP. SEE ALSO
kctune(1M), sam(1M), gettune(2), settune(2). Tunable Kernel Parameters ninode(5)
