ramutil(1M)

NAME

ramutil — utility to create or destroy RAM disk volumes

SYNOPSIS

/usr/sbin/ramutil [-l] -c -v volume_number -s volume_size

/usr/sbin/ramutil -d -v volume_number

/usr/sbin/ramutil -f

DESCRIPTION

The ramutil utility is used to create and destroy RAM disk volumes on the system. The system administator must configure additional swap devices and also modify the maxdsiz_64bit tunable in order to create large swappable RAM disk volumes.

Options

ramutil recognizes the following options:

-c

Creates the RAM disk volume, the associated node, and the device special files.

The character device special file is created as /dev/rdsk/ram volume_number. The block device special file is created as /dev/dsk/ram volume_number.

The -v and -s options are mandatory with this option.

The -l option can be used with this option to create a nonswappable RAM disk.

-d

Destroy the specified RAM disk volume if there are no applications running on it.

The -v option is mandatory with this option.

-f

Recreate any missing RAM disk device special files.

-l

Create nonswappable RAM disk. This option should be used with caution since it creates RAM disk that reserves physical memory on the system equal to its size.

-s volume_size

Specify the size of the RAM disk volume to be created. The size parameter can be given in bytes, kilobytes, or gigabytes. For bytes, specify the number; for kilobytes, append the number with a k; for gigabytes, append the number with a g.

If the RAM disk volume size is greater than 64 KB and the volume size is not a multiple of 64 KB blocks, then the size of the RAM disk volume is rounded off to the next 64 KB block. If the RAM disk volume size is greater than 4 GB and the volume size is not a multiple of 1 GB blocks, then the size of the RAM disk volume is rounded off to the next 1 GB block.

-v volume_number

Associate a volume number with a RAM disk. Fifteen RAM disk volumes are supported on a system. The volume number can be any number in the range of 1 to 14 (certain other volume numbers are reserved).

EXAMPLES

Create a swappable RAM disk that has a size of 6 GB and volume number 3:

ramutil -c -v 3 -s 6g 

Destroy the RAM disk with volume number 3:

ramutil -d -v 3 

WARNINGS

HP-UX 11i v2 (11.23) Ramdisc version 1 has not been certified for use with HP's Logical Volume Manager (LVM) in mirrored configurations. HP does not support such configurations since there is a possibility of data loss from a redundancy failure of a physical disk or disk interface component. Other LVM mirrored configuration failure modes may exist that may further impact data integrity. Note: RAM disk data is not persistent across system reboots.

HP disclaims all warranties, express or implied, including but not limited to the implied warranties of merchantability, fitness for a particular purpose, and noninfringement, if you use HP-UX 11i v2 (11.23) Ramdisc version 1 with LVM mirrored configurations, and you assume all responsibility for any problems resulting from such usage in these configurations.

Third party products exist that provide RAM-disk based LVM mirrored configurations with additional support software; these products are delivered on configurations tested and validated by the product vendor. The use of such products is permitted on 11i v2 (11.23); the third party product vendors are responsible for supporting these products.

AUTHOR

ramutil was developed by HP.

FILES

/dev/dsk/ramvolume_number: block device for RAM disk volume
/dev/rdsk/ramvolume_number: raw device for RAM disk volume

When the RAM disk volume is created with -c, these RAM disk device special files are created. When the RAM disk volume is destroyed using the -d option, these files are automatically removed.

ramutil(1M)

Technical documentation

» Table of Contents

» Index