根据手册:
mount_opts=mount_option_string
Set a set of default mount options which will be used when the file
system is mounted. Unlike the bitmask-based default mount options
which can be specified with the -o option, mount_option_string is an
arbitrary string with a maximum length of 63 bytes, which is stored in
the superblock.
如果我尝试设置一个选项,它会起作用:
$ tune2fs -E mount_opts=data=writeback /dev/sde2
tune2fs 1.43.5 (04-Aug-2017)
Setting extended default mount options to 'data=writeback'
但如果我尝试设置多个选项,它似乎与tune2fs
自己的解析机制冲突:
$ tune2fs -E mount_opts=data=writeback,noatime /dev/sde2
tune2fs 1.43.5 (04-Aug-2017)
Bad options specified.
Extended options are separated by commas, and may take an argument which
is set off by an equals ('=') sign.
Valid extended options are:
clear_mmp
hash_alg=<hash algorithm>
mount_opts=<extended default mount options>
stride=<RAID per-disk chunk size in blocks>
stripe_width=<RAID stride*data disks in blocks>
test_fs
^test_fs
如何在‘mount_opts’上传递包含多个选项的字符串?
答案1
正如 Thomas 所说,sparated by commas
是用于扩展选项分离。但是,选项分离也可以使用(参见 Linux 内核)mount_opts
完成,并且从这个答案开始',
fs/ext4/super.c:parse_options()
e2fsprogs
mke2fs
和 tune2fs
无法在语义上区分彼此。
是的,这是tune2fs的一个缺点。
没有使用常见ext
操作工具实现此目的的语法。Ts'o 建议使用debugfs
以下解决方法:
您可以使用 debugfs 设置扩展挂载选项:
debugfs -w -R "set_super_value mount_opts foo,bar" /dev/sda1
在这种情况下,您需要debugfs -w -R "set_super_value mount_opts data=writeback,noatime" /dev/sde2
,但是这并没有达到你预期的效果。
在安装时,ext4
内核模块会抱怨Unrecognized mount option "noatime" or missing value
;事实上,它只能指定ext
特定于选项,并且noatime
不能(参见相同的内核源文件,可用的选项列在数组中tokens
)。功能上最接近的匹配是lazytime
。
因此,使用debugfs -w -R "set_super_value mount_opts data=writeback,lazytime" /dev/sde2
。
答案2
sparated by commas
与不同的扩展选项相关,如,clear_mmp
等。hash_alg
mount_opts
因此正确的语法如下。
tune2fs -E mount_opts="data=writeback noatime" /dev/sde1