initrd(4) Device Drivers Manual initrd(4) initrd - RAM-, /dev/initrd -- , , 1 250. , /dev/initrd root:disk 0400 ( root). /dev/initrd , : mknod -m 400 /dev/initrd b 1 250 chown root:disk /dev/initrd /dev/initrd << RAM>> << RAM>> Linux CONFIG_BLK_DEV_RAM=y CONFIG_BLK_DEV_INITRD=y. /dev/initrd RAM . /dev/initrd -- , . , , (.. ) . /dev/initrd . /dev/initrd (, RAM-, ). . (.., ). initrd : (1) /dev/initrd . (2) , /dev/initrd /dev/ram0, , /dev/initrd. (3) /dev/ram0 . (4) (, /dev/ram0), . (5) /linuxrc, UID 0. /linuxrc . /linuxrc , . (6) /linuxrc /linuxrc , . /linuxrc - , , . . (7) /initrd, /dev/ram0 / /initrd. , /initrd , /dev/ram0 . / /initrd /dev/ram0 , , /dev/ram0, . /initrd - /dev/ram0 /linuxrc, . . (8) (, /sbin/init) . initrd : initrd=_ , /dev/initrd. LOADLIN . LILO LILO -- /etc/lilo.config. , , , gzip. noinitrd . , /dev/initrd . /dev/initrd, , . /dev/initrd , . , /dev/initrd . root=_ , . LOADLIN LILO LILO -- /etc/lilo.config. , , , . By default, the kernel's settings (e.g., set in the kernel file with rdev(8) or compiled into the kernel file), or the boot loader option setting is used for the normal root filesystems. For an NFS-mounted normal root filesystem, one has to use the nfs_root_name and nfs_root_addrs boot options to give the NFS settings. For more information on NFS-mounted root see the kernel documentation file Documentation/filesystems/nfs/nfsroot.rst. For more information on setting the root filesystem see also the LILO and LOADLIN documentation. /linuxrc. /proc. /proc, /linuxrc proc- /proc/sys/kernel/real-root-dev, /proc/sys/kernel/nfs-root-name /proc/sys/kernel/nfs-root-addrs. /linuxrc /proc/sys/kernel/real-root-dev. NFS /linuxrc NFS /proc/sys/kernel/nfs-root-name /proc/sys/kernel/nfs-root-addrs, 0xff ( -NFS-) /proc/sys/kernel/real-root-dev. , , /dev/hdb1: echo 0x365 >/proc/sys/kernel/real-root-dev c NFS, NFS /var/nfsroot NFS- IP- 193.8.232.7 IP- 193.8.232.2 'idefix': echo /var/nfsroot >/proc/sys/kernel/nfs-root-name echo 193.8.232.2:193.8.232.7::255.255.255.0:idefix \ >/proc/sys/kernel/nfs-root-addrs echo 255 >/proc/sys/kernel/real-root-dev Note: The use of /proc/sys/kernel/real-root-dev to change the root filesystem is obsolete. See the Linux kernel source file Documentation/admin-guide/initrd.rst as well as pivot_root(2) and pivot_root(8) for information on the modern method of changing the root filesystem. initrd . : (1) - (, /dev/ram, /dev/initrd ext2) /dev/initrd , gzip. (2) /linuxrc : (1) , (.., , , ) (2) (, CD-ROM, , , ). , . (3) /linuxrc . (4) /linuxrc ( ). (5) /linuxrc /proc/sys/kernel/real-root-dev, /proc, , , . (6) . (7) , , . (8) , /dev/initrd , (, /dev/ram0 , , , /dev/ram0 ). (9) , . /dev/initrd -- , . , initrd -- Linux . ( -- ) . . /linuxrc , /linuxrc. -- . , , , /dev/initrd / , , . , Linux CD-ROM initrd CD-ROM. LOADLIN /dev/initrd CD-ROM . LILO /dev/initrd RAM-, CD-ROM. /dev/initrd /dev/ram0 /linuxrc /initrd o , , /dev/ram0 / /initrd, . , /proc/mounts . o , /initrd , /dev/ram0 , /dev/ram0 - - . /dev/ram0 , /dev/ram0 . o /dev/initrd , . Linux . chown(1), mknod(1), ram(4), freeramdisk(8), rdev(8) Documentation/admin-guide/initrd.rst in the Linux kernel source tree, the LILO documentation, the LOADLIN documentation, the SYSLINUX documentation () Azamat Hackimov , Dmitriy S. Seregin , Yuri Kozlov ; GNU (GNU General Public License - GPL, 3 ) , - . - , , () () () . Linux man-pages 6.18 8 2026 . initrd(4)