admin-guide/blockdev/ramdisk.rst

2 Using the RAM disk block device with Linux
10 	4) An Example of Creating a Compressed RAM Disk
16 The RAM disk driver is a way to use main system memory as a block device.  It
22 The RAM disk dynamically grows as more space is required. It does this by using
23 RAM from the buffer cache. The driver marks the buffers it is using as dirty
26 The RAM disk supports up to 16 RAM disks by default, and can be reconfigured
27 to support an unlimited number of RAM disks (at your own risk).  Just change
31 To use RAM disk support with your system, run './MAKEDEV ram' from the /dev
32 directory.  RAM disks are all major number 1, and start with minor number 0
35 The new RAM disk also has the ability to load compressed RAM disk images,
48 This parameter tells the RAM disk driver to set up RAM disks of N k size.  The
84 4) An Example of Creating a Compressed RAM Disk
87 To create a RAM disk image, you will need a spare block device to
88 construct it on. This can be the RAM disk device itself, or an
90 example, we will use the RAM disk device, "/dev/ram0".
93 of RAM. If using a spare disk partition instead of /dev/ram0, then this
96 a) Decide on the RAM disk size that you want. Say 2 MB for this example.
97    Create it by writing to the RAM disk device. (This step is not currently
111 d) Compress the contents of the RAM disk. The level of compression
113    space on the RAM disk will compress to almost nothing::
121 f) Put the RAM disk image onto the floppy, after the kernel. Use an offset
124    the RAM disk image. An offset of 400 kB for kernels about 350 kB in
134 That is it. You now have your boot/root compressed RAM disk floppy. Some