mount default options

OutSiderBR · 09-13-2018, 05:51 PM

In OpenSUSE Leap 15, if I type as root

Code:

mount /dev/sdb1 /mnt/tmp

for a USB stick with vfat (partition type b), Leap automatically uses default options and mounts it like:

Code:

/dev/sdb1 on /mnt/tmp type vfat (rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro)

If I type in the same command in Slackware I get different default mount options:

Code:

/dev/sdb1 on /mnt/tmp type vfat (rw)

What configuration files should I change to mimic the Leap15 mount options?

Thanks for the attention.

Stéphane Ascoët · 09-14-2018, 01:56 AM

/etc/fstab if the key will always be in /dev/sdb1

Otherwise you'll have to deal with udev rules and I'm not expert in this.

lecho · 09-14-2018, 07:20 AM

It seems that the "mount" command does not print all options used for a given mountpoint. Try the "findmnt" command or "cat /proc/mounts" to check options in use.

Nille_kungen · 09-14-2018, 07:48 AM

What is it that you want to do and why?
Do you want to set specific permissions or charset for one drive?
What functionality is it that you are missing

bassmadrigal · 09-14-2018, 10:53 AM

Quote:

Originally Posted by Stéphane Ascoët

/etc/fstab if the key will always be in /dev/sdb1

Otherwise you'll have to deal with udev rules and I'm not expert in this.

You could also use persistent naming in the fstab if /dev/sdb1 could change. Something like a label or UUID would work.

OutSiderBR · 09-17-2018, 08:17 AM

Thank you all very much for the replies. I was just curious about how to set this default rule. It may well be in udev, indeed. I know how to set the default options in fstab or on the command line as root, no problem with that. I would like to tweak my Slack o behave like that. I will search a bit further and check Leap 15 rules.

Once again, thank you very much.

Didier Spaier · 09-17-2018, 09:04 AM

My question would be why you want the same default options.

As an aside, and for a vfat file system if I read correctly the man page for the mount command:

codepage=437 is the default so this option is useless.
iocharset=iso8859-1 is the default so this option is useless.

OutSiderBR · 09-17-2018, 10:07 AM

Didier, I would like to know it out of curiosity only. Suppose I want to set the default page to iso8859-15 with the euro sign. I would like to know how to do it. Just for the sake of knowing it.

bassmadrigal · 09-17-2018, 11:28 AM

Quote:

Originally Posted by OutSiderBR

Didier, I would like to know it out of curiosity only. Suppose I want to set the default page to iso8859-15 with the euro sign. I would like to know how to do it. Just for the sake of knowing it.

Some of them are set in the kernel. I don't have a modern config in front of me, but I was able to extract this from an old page at the ArchWiki (it has since been merged with other articles and that information no longer resides on the current article).

Code:

$ zgrep -e FAT -e DOS /proc/config.gz | sort -r 
# DOS/FAT/NT Filesystems
CONFIG_FAT_FS=m
CONFIG_MSDOS_PARTITION=y
CONFIG_FAT_FS=m
CONFIG_MSDOS_FS=m
CONFIG_VFAT_FS=m
CONFIG_FAT_DEFAULT_CODEPAGE=437
CONFIG_FAT_DEFAULT_IOCHARSET="iso8859-1"
CONFIG_NCPFS_SMALLDOS=y

Leap might also have a script when calling mount.vfat to specify specific options (also found on that ArchWiki page).

Code:

/usr/bin/mount.vfat
#!/bin/bash
#mount VFAT with full rw (read-write) permissions for all users
#/usr/bin/mount -i -t vfat -oumask=0000,iocharset=utf8 "$@"
#The above is the same as
mount -i -t vfat -oiocharset=utf8,fmask=0000,dmask=0000 "$@"

OutSiderBR · 09-17-2018, 01:27 PM

Thanks, bassmadrigal.

Loomx · 09-17-2018, 02:18 PM

Did you try the `findmnt' command as @lecho suggested?

If I do that I find that a vfat device is actually mounted with the same default options as Leap, it's just that the `mount' command doesn't show them by default.

OutSiderBR · 09-18-2018, 06:03 AM

Quote:

Originally Posted by Loomx

Did you try the `findmnt' command as @lecho suggested?

If I do that I find that a vfat device is actually mounted with the same default options as Leap, it's just that the `mount' command doesn't show them by default.

I did it and in fact the options are there. Now I know that there are some places to set the default parameters. Thanks a lot !