内存文件系统使用_t2080 linux-优快云博客

作者

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参考

linux内存文件系统之指南
 Linux——内存文件系统
 Linux中ramdisk,tmpfs,ramfs的介绍与分析

ramdisk

root@t2080rdb:~# df -T
Filesystem           Type       1K-blocks      Used Available Use% Mounted on
ubi0:rootfs          ubifs         200396     83384    112176  43% /
devtmpfs             devtmpfs     1720260         4   1720256   0% /dev
tmpfs                tmpfs        1720448       220   1720228   0% /run
tmpfs                tmpfs        1720448     42832   1677616   2% /var/volatile
root@t2080rdb:~# mkfs -t ext4 /dev/ram0
mke2fs 1.42.9 (28-Dec-2013)
Discarding device blocks: done                            
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
Stride=0 blocks, Stripe width=0 blocks
32768 inodes, 131072 blocks
6553 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=67371008
16 block groups
8192 blocks per group, 8192 fragments per group
2048 inodes per group
Superblock backups stored on blocks: 
        8193, 24577, 40961, 57345, 73729

Allocating group tables: done                            
Writing inode tables: done                            
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done 

root@t2080rdb:~# mkdir ram
root@t2080rdb:~# mount -t ext4 /dev/ram0 ./ram
EXT4-fs (ram0): mounted filesystem with ordered data mode. Opts: (null)
root@t2080rdb:~# df -T 
Filesystem           Type       1K-blocks      Used Available Use% Mounted on
ubi0:rootfs          ubifs         200396     83384    112172  43% /
devtmpfs             devtmpfs     1720260         4   1720256   0% /dev
tmpfs                tmpfs        1720448       220   1720228   0% /run
tmpfs                tmpfs        1720448     42832   1677616   2% /var/volatile
/dev/ram0            ext4          122835      1550    112111   1% /home/root/ram
root@t2080rdb:~# cd ram
root@t2080rdb:~/ram# 
root@t2080rdb:~/ram# ls
lost+found
root@t2080rdb:~/ram# vi text
root@t2080rdb:~/ram# cat text 
fgiasdgjas

ramfs

Ramfs被限制最多可使用内存大小的一半，maxsize（默认以kbyte为单位）

root@t2080rdb:~# mount -t ramfs none ./ram -o maxsize=128m
root@t2080rdb:~# ls ./ram
root@t2080rdb:~# vi ./ram/hd
root@t2080rdb:~# cat ram/hd 
aklsjdfgsdj
root@t2080rdb:~# df -T
Filesystem           Type       1K-blocks      Used Available Use% Mounted on
ubi0:rootfs          ubifs         200396     83384    112172  43% /
devtmpfs             devtmpfs     1720260         4   1720256   0% /dev
tmpfs                tmpfs        1720448       220   1720228   0% /run
tmpfs                tmpfs        1720448     42832   1677616   2% /var/volatile
root@t2080rdb:~# mount
ubi0:rootfs on / type ubifs (rw,relatime)
devtmpfs on /dev type devtmpfs (rw,relatime,size=1720260k,nr_inodes=430065,mode=755)
proc on /proc type proc (rw,relatime)
sysfs on /sys type sysfs (rw,relatime)
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
tmpfs on /run type tmpfs (rw,nosuid,nodev,mode=755)
tmpfs on /var/volatile type tmpfs (rw,relatime)
devpts on /dev/pts type devpts (rw,relatime,gid=5,mode=620)
none on /home/root/ram type ramfs (rw,relatime,maxsize=128m)