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ramdiskadm(1m) [opensolaris man page]

ramdiskadm(1M)						  System Administration Commands					    ramdiskadm(1M)

NAME
ramdiskadm - administer ramdisk pseudo device SYNOPSIS
/usr/sbin/ramdiskadm -a name size [g | m | k | b] /usr/sbin/ramdiskadm -d name /usr/sbin/ramdiskadm DESCRIPTION
The ramdiskadm command administers ramdisk(7D), the ramdisk driver. Use ramdiskadm to create a new named ramdisk device, delete an existing named ramdisk, or list information about existing ramdisks. Ramdisks created using ramdiskadm are not persistent across reboots. OPTIONS
The following options are supported: -a name size Create a ramdisk named name of size size and its corresponding block and character device nodes. name must be composed only of the characters a-z, A-Z, 0-9, _ (underbar), and - (hyphen), but it must not begin with a hyphen. It must be no more than 32 characters long. Ramdisk names must be unique. The size can be a decimal number, or, when prefixed with 0x, a hexadecimal number, and can specify the size in bytes (no suffix), 512-byte blocks (suffix b), kilobytes (suffix k), megabytes (suffix m) or gigabytes (suffix g). The size of the ramdisk actually created might be larger than that specified, depending on the hardware implementation. If the named ramdisk is successfully created, its block device path is printed on standard out. -d name Delete an existing ramdisk of the name name. This command succeeds only when the named ramdisk is not open. The associated memory is freed and the device nodes are removed. You can delete only ramdisks created using ramdiskadm. It is not possible to delete a ramdisk that was created during the boot process. Without options, ramdiskadm lists any existing ramdisks, their sizes (in decimal), and whether they can be removed by ramdiskadm (see the description of the -d option, above). EXAMPLES
Example 1 Creating a 2MB Ramdisk Named mydisk # ramdiskadm -a mydisk 2m /dev/ramdisk/mydisk Example 2 Listing All Ramdisks # ramdiskadm Block Device Size Removable /dev/ramdisk/miniroot 134217728 No /dev/ramdisk/certfs 1048576 No /dev/ramdisk/mydisk 2097152 Yes EXIT STATUS
ramdiskadm returns the following exit values: 0 Successful completion. >0 An error occurred. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWcsr | +-----------------------------+-----------------------------+ |Interface Stability |Evolving | +-----------------------------+-----------------------------+ SEE ALSO
attributes(5), ramdisk(7D) NOTES
The abilities of ramdiskadm and the privilege level of the person who uses the utility are controlled by the permissions of /dev/ramdiskctl. Read access allows query operations, for example, listing device information. Write access is required to do any state- changing operations, for example, creating or deleting ramdisks. As shipped, /dev/ramdiskctl is owned by root, in group sys, and mode 0644, so all users can do query operations but only root can perform state-changing operations. An administrator can give write access to non-privileged users, allowing them to add or delete ramdisks. How- ever, granting such ability entails considerable risk; such privileges should be given only to a trusted group. SunOS 5.11 25 Mar 2003 ramdiskadm(1M)

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ramdisk(7D)							      Devices							       ramdisk(7D)

NAME
ramdisk - RAM disk device driver SYNOPSIS
ramdisk@0:diskname DESCRIPTION
The ramdisk driver supports numerous ramdisk devices that are created by the system during the boot process (see boot(1M)) or during nor- mal system operation (see ramdiskadm(1M) for more information). DEVICE SPECIAL FILES
Each ramdisk can be accessed either as a block device or as a raw device. When accessed as a block device, the normal buffering mechanism is used when reading from and writing to the device, without regard to physical disk records. Accessing the ramdisk as a raw device enables direct transmission between the disk and the read or write buffer. A single read or write call usually results in a single I/O operation, meaning that raw I/O is more efficient when many bytes are transmitted. You can find block files names in /dev/ramdisk. Raw file names are found in /dev/rramdisk. There are no alignment or length restrictions on I/O requests to either block or character devices. ERRORS
EFAULT The argument features a bad address. EINVAL Invalid argument. EIO. An I/O error occurred. EPERM Cannot create or delete a ramdisk without write permission on /dev/ramdiskctl. ENOTTY The device does not support the requested ioctl function. ENXIO The device did not exist during opening. EBUSY Cannot exclusively open /dev/ramdiskctl. One or more ramdisks are still open. EEXIST A ramdisk with the indicated name already exists. EAGAIN Cannot allocate resource for ramdisk. Try again later. FILES
/dev/ramdisk/diskname Block device for ramdisk named diskname. /dev/rramdisk/diskname Raw device for ramdisk name diskname /kernel/drv/ramdisk 32-bit driver /kernel/drv/ramdisk.conf Driver configuration file. (Do not alter). /kernel/drv/sparcv9/ramdisk 64-bit driver ATTRIBUTES
See attributes(5) for descriptions of the following attribute: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Evolving | +-----------------------------+-----------------------------+ SEE ALSO
ramdiskadm(1M), fsck(1M), fstyp(1M), mount(1M), newfs(1M), driver.conf(4), filesystem(5), dkio(7I) NOTES
The percentage of available physical memory that can be allocated to ramdisks is constrained by the variable rd_percent_physmem. You can tune the rd_percent_physmem variable in /etc/system. By default, the percentage of available physical memory that can be allocated to ramdisks is fixed at 25%. A ramdisk may not be the best possible use of system memory. Accordingly, use ramdisks only when absolutely necessary. SunOS 5.11 04 Mar 2003 ramdisk(7D)
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