Veritas File System 4.1 Administrator's Guide (HP-UX 11i v3, February 2007)

VxFS Performance: Creating, Mounting, and Tuning File Systems
I/O Tuning
Chapter 2 49
inode_aging_count Specifies the maximum number of inodes to place on an inode aging
list. Inode aging is used in conjunction with file system Storage
Checkpoints to allow quick restoration of large, recently deleted
files. The aging list is maintained in first-in-first-out (fifo) order up to
maximum number of inodes specified by inode_aging_count.
As newer inodes are placed on the list, older inodes are removed to
complete their aging process. For best performance, it is advisable to
age only a limited number of larger files before completion of the
removal process. The default maximum number of inodes to age is
2048.
inode_aging_size Specifies the minimum size to qualify a deleted inode for inode
aging. Inode aging is used in conjunction with file system Storage
Checkpoints to allow quick restoration of large, recently deleted
files. For best performance, it is advisable to age only a limited
number of larger files before completion of the removal process.
Setting the size too low can push larger file inodes out of the aging
queue to make room for newly removed smaller file inodes.
max_direct_iosz The maximum size of a direct I/O request that will be issued by the
file system. If a larger I/O request comes in, then it is broken up into
max_direct_iosz chunks. This parameter defines how much
memory an I/O request can lock at once, so it should not be set to
more than 20 percent of memory.
max_diskq Limits the maximum disk queue generated by a single file. When the
file system is flushing data for a file and the number of buffers being
flushed exceeds max_diskq, processes will block until the amount
of data being flushed decreases. Although this doesn't limit the actual
disk queue, it prevents flushing processes from making the system
unresponsive. The default value is 1 MB.