Re: sharing one r/w unix filesystem between different machines and users
Can you use the other permission set? Or does it need to be specifically those users only? Permission schemes on removable media are not too powerful annyway, as anyone with root on any machine can change them... my $0.02. -- rbmj
Re: sharing one r/w unix filesystem between different machines and users
Blair Mason writes: > Permission schemes on removable media are not too powerful annyway, as > anyone with root on any machine can change them... my $0.02. Exactly -- I wonder whether there are any decent (modern features, public specification, nice free implementation, etc.) filesystems which allow to ignore permissions when mounted by a user. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/87aaaxksbi@falma.de
Re: sharing one r/w unix filesystem between different machines and users
On Fri, 26 Aug 2011 01:02:57 +0200 Christoph Groth wrote: > Blair Mason writes: > > > Permission schemes on removable media are not too powerful annyway, > > as anyone with root on any machine can change them... my $0.02. > > Exactly -- I wonder whether there are any decent (modern features, > public specification, nice free implementation, etc.) filesystems > which allow to ignore permissions when mounted by a user. > > Will something like the following work? This works on any filesystem using standard unix permissions (such as ext*, ufs, reiserfs*, btrfs, etc.) Suppose your filesystem is mounted on /media/usb0. # chmod -R a+rwx /media/usb0 This does, however, seem the Wrong Way To Do It, as it will not work for files created after issuing the command. Unfortunately, there isn't an elegant way to do this. It seems like it should be an option to mount (something like ignoreperms). Looking at the internet, it appears that OSX has a mount option to do this: http://developer.apple.com/library/mac/#documentation/Darwin/Reference/ManPages/man8/mount.8.html (search for 'noowners') This option does not appear to exist on Linux or BSD, however. Hope this helps, -- rbmj -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20110825210600.239a0...@blairasus.mason.homeunix.org
Re: sharing one r/w unix filesystem between different machines and users
On Thu, Aug 25, 2011 at 19:02, Christoph Groth wrote: > Blair Mason writes: > >> Permission schemes on removable media are not too powerful annyway, as >> anyone with root on any machine can change them... my $0.02. > > Exactly -- I wonder whether there are any decent (modern features, > public specification, nice free implementation, etc.) filesystems which > allow to ignore permissions when mounted by a user. > so, the old school way is to use nis (or ypbind). this will still work for you (it isn't secure but you can set it up in a few minutes. the modern way is ldap and a ticketing system (kerberos) but seriously, don't try - it's hard and overkill. the end result is to have global uid / gid. then you setup nfs and export for that ip / mask and you can mount it from your remote host. what i'd suggest is to export /mnt and have your host automatically mount devices under a subdirectory to /mnt and then you'll be able to read it from your remote host. you could even have udev do a 'notify-send' to your remote machines when you insert media (but, obviously this is overkill since you know when you've inserted media into your own computers - just fun :) ). -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/cah_obidoaldxzizb5yvif+h32lverwobs3hdhuxs7vdr41_...@mail.gmail.com
Re: sharing one r/w unix filesystem between different machines and users
"Robert Blair Mason Jr." writes: > Christoph Groth wrote: > >> Blair Mason writes: >> >> > Permission schemes on removable media are not too powerful annyway, >> > as anyone with root on any machine can change them... my $0.02. >> >> Exactly -- I wonder whether there are any decent (modern features, >> public specification, nice free implementation, etc.) filesystems >> which allow to ignore permissions when mounted by a user. >> > Will something like the following work? This works on any filesystem > using standard unix permissions (such as ext*, ufs, reiserfs*, btrfs, > etc.) > > Suppose your filesystem is mounted on /media/usb0. > > # chmod -R a+rwx /media/usb0 > > This does, however, seem the Wrong Way To Do It, as it will not work > for files created after issuing the command. That's the point. If user A creates some directory, and user B (who has a different uid on his machine) wants to delete a file in this directory, user B will have first to become root and override the permissions. This is an unnecessary hassle and requires the user in question to be fairly technical. And it won't work if the user is unable to become root. > Unfortunately, there isn't an elegant way to do this. It seems like it > should be an option to mount (something like ignoreperms). Looking at > the internet, it appears that OSX has a mount option to do this: > > http://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man8/mount.8.html > (search for 'noowners') > > This option does not appear to exist on Linux or BSD, however. Thanks, I've been looking for something like this (though an OSX solution doesn't help me). I really wonder why no one has ever fixed this issue for Linux -- probably everybody is happy simply using FAT and NTFS on shared removable media. And their importance is fading anyway. Thanks, Christoph -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/87ty94wu74@falma.de
Re: sharing one r/w unix filesystem between different machines and users
shawn wilson writes: > On Thu, Aug 25, 2011 at 19:02, Christoph Groth wrote: >> Blair Mason writes: >> >>> Permission schemes on removable media are not too powerful annyway, as >>> anyone with root on any machine can change them... my $0.02. >> >> Exactly -- I wonder whether there are any decent (modern features, >> public specification, nice free implementation, etc.) filesystems which >> allow to ignore permissions when mounted by a user. Thanks, but any solution requiring to run additional servers to solve this simple issue doesn't feel like the proper one. I think the idea that a user should be able to control _fully_ the devices which he attaches himself is not really supported well in Linux. The issue is not trivial to solve, because who should own a newly attached device if several users are logged in? (It should be the current user of the physical terminal to which the new device has been connected.) Is anyone aware of an emerging solution to this? Christoph -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/87pqjswtla@falma.de
Re: sharing one r/w unix filesystem between different machines and users
Hi Christoph, Why not use an UDF filesystem, that is used on DVD discs? "Christoph Groth" schreef in bericht news:87hb55ku8x@falma.de... Hi, I'd like to share the data saved on an external USB drive between different (GNU/Linux) machines, each having different users. Each user should be able to mount the drive and read and write any files as he or she pleases. The users aren't necessary root themselves. Is there a way to implement such a scheme with a non-windows filesystem like ext3? I understand how Unix file permissions work. However, for a removable drive which might be connected to different systems (with completely unrelated uids/gids), assigning fixed uids/gids to files just doesn't make any sense. What's the best FS for sharing data between unrelated Linux systems? Is it really FAT or NTFS? Thanks, Christoph -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/j37p1m$njq$1...@dough.gmane.org
Re: sharing one r/w unix filesystem between different machines and users
On Fri, 26 Aug 2011 08:41:35 +0200 Christoph Groth wrote: > "Robert Blair Mason Jr." writes: > > > Christoph Groth wrote: > > > > Will something like the following work? This works on any filesystem > > using standard unix permissions (such as ext*, ufs, reiserfs*, > > btrfs, etc.) > > > > Suppose your filesystem is mounted on /media/usb0. > > > > # chmod -R a+rwx /media/usb0 > > > > This does, however, seem the Wrong Way To Do It, as it will not work > > for files created after issuing the command. > > That's the point. If user A creates some directory, and user B (who > has a different uid on his machine) wants to delete a file in this > directory, user B will have first to become root and override the > permissions. This is an unnecessary hassle and requires the user in > question to be fairly technical. And it won't work if the user is > unable to become root. > > > Unfortunately, there isn't an elegant way to do this. It seems like > > it should be an option to mount (something like ignoreperms). > > Looking at the internet, it appears that OSX has a mount option to > > do this: > > > > http://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man8/mount.8.html > > (search for 'noowners') > > > > This option does not appear to exist on Linux or BSD, however. > > Thanks, I've been looking for something like this (though an OSX > solution doesn't help me). I really wonder why no one has ever fixed > this issue for Linux -- probably everybody is happy simply using FAT > and NTFS on shared removable media. And their importance is fading > anyway. > I understand OSX doesn't help anyone here... perhaps someone could request an implementation of this command in the mount source code? It seems simple - just check if the filesystem has noowners set and if so, instead of fetching permissions from disk, return -rwxrwxrwx. But these things are never as simple as they seem... -- rbmj -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20110828100105.73c35...@blairasus.mason.homeunix.org
Re: sharing one r/w unix filesystem between different machines and users
On Sun, 28 Aug 2011 10:01:05 -0400 "Robert Blair Mason Jr." wrote: > > I understand OSX doesn't help anyone here... perhaps someone could > request an implementation of this command in the mount source code? > It seems simple - just check if the filesystem has noowners set and if > so, instead of fetching permissions from disk, return -rwxrwxrwx. But > these things are never as simple as they seem... > Actually, a quick skim over the mount(8) source code shows that all of the changes would actually have to be done in the mount(2) source code - which I believe is in the kernel :( -- rbmj -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20110828133158.132b4...@blairasus.mason.homeunix.org
Re: sharing one r/w unix filesystem between different machines and users
I don't understand what is hard about this. I mean if you don't care about security, just make sure the mount has a umask of 770 (or whatever) and make an export, reload exports, and mount it from wherever you want. What am I missing? Also, if you want to call osx Unix, call it broken unix. Most people say its 'unix like' though. What I mean is that Apple changed basic unix commands around which osx not act right. And then it is possibly closer in comparison to windows than it is to Linux. On Aug 28, 2011 3:33 PM, "Robert Blair Mason Jr." wrote: > On Sun, 28 Aug 2011 10:01:05 -0400 > "Robert Blair Mason Jr." wrote: >> >> I understand OSX doesn't help anyone here... perhaps someone could >> request an implementation of this command in the mount source code? >> It seems simple - just check if the filesystem has noowners set and if >> so, instead of fetching permissions from disk, return -rwxrwxrwx. But >> these things are never as simple as they seem... >> > > Actually, a quick skim over the mount(8) source code shows that all of > the changes would actually have to be done in the mount(2) source code > - which I believe is in the kernel :( > > -- > rbmj > > > -- > To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org > with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org > Archive: http://lists.debian.org/20110828133158.132b4...@blairasus.mason.homeunix.org >
Re: sharing one r/w unix filesystem between different machines and users
On Sun, 28 Aug 2011 19:18:35 -0400 shawn wilson wrote: > I don't understand what is hard about this. I mean if you don't care > about security, just make sure the mount has a umask of 770 (or > whatever) and make an export, reload exports, and mount it from > wherever you want. > > What am I missing? I believe you're missing the point that the user isn't using NFS - this isn't shared files over a network, it's shared files over a shared disk. And a mask of 770 only means that it will preserve other permissions AFAIK - it won't set them. > Also, if you want to call osx Unix, call it broken unix. Most people > say its 'unix like' though. What I mean is that Apple changed basic > unix commands around which osx not act right. And then it is possibly > closer in comparison to windows than it is to Linux. I would agree that it is broken Unix, the point was just to demonstrate that a solution has been implemented somewhere else, and that it should be possible. I disagree that OSX is closer to windows than linux. The small amount of unix it inherits from darwin makes it orders of magnitude more robust than 'doze :). -- rbmj -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20110829102410.7deb8...@blairasus.mason.homeunix.org
Re: sharing one r/w unix filesystem between different machines and users
"Lars Maes" writes: > Why not use an UDF filesystem, that is used on DVD discs? Indeed, this seems to work well. It is a better option than VFAT and NTFS. I didn't know that the filesystem of DVDs is also usable for rewriteable media, but I have learned that UDF has been designed with that in mind, too. Thanks! Christoph -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/8762lf2g6v@falma.de
Re: sharing one r/w unix filesystem between different machines and users
Christoph Groth writes: > "Lars Maes" writes: > >> Why not use an UDF filesystem, that is used on DVD discs? > > Indeed, this seems to work well. It is a better option than VFAT and > NTFS. I didn't know that the filesystem of DVDs is also usable for > rewriteable media, but I have learned that UDF has been designed with > that in mind, too. Thanks! It only works well on a small USB flash drive. Formatting a 2 TB external HD with UDF also works, but it's not possible to fill it beyond 2% because of the following bug: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/583949 I can observe this bug with kernel 3.0. So I tried NTFS, but it sucks, because there seems to be no way (other than sudo) for normal users to mount NTFS filesystems (with ntfs-3g). Setting the configuration option of the ntfs-3g package to "yes" doesn't help. So I'm back to ext2/3/4 again, and as long as I'm using my drive just for myself everything is fine. If there are other options for sharing a huge external disk between different computers (ideally different OSes), such that on Linux machines non-superusers can modify all files, I'd be glad to hear about them. Christoph -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/8762l99ykw@falma.de
Re: sharing one r/w unix filesystem between different machines and users
Putting a directory like /tmp (with the same permissions on the USB drive) would allow any user to create files and directories there. If this user sets permissions for own files to allow others to read and write, any other user is able to overwrite the contents of this files. Any user can mount the drive with the pmount command. The ownership and permissions are stored in the filesystem on the USB drive. -- Best regards, Jörg-Volker. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/j40dal$h04$1...@dough.gmane.org
Re: sharing one r/w unix filesystem between different machines and users
On Fri, Aug 26, 2011 at 12:21:18AM +0200, Christoph Groth wrote: > Hi, > > I'd like to share the data saved on an external USB drive between > different (GNU/Linux) machines, each having different users. Each user > should be able to mount the drive and read and write any files as he or > she pleases. The users aren't necessary root themselves. > > Is there a way to implement such a scheme with a non-windows filesystem > like ext3? > > I understand how Unix file permissions work. However, for a removable > drive which might be connected to different systems (with completely > unrelated uids/gids), assigning fixed uids/gids to files just doesn't > make any sense. This is untested ... Use: user = nobody 65534 group = users 100 or nogroup 65534 Then use BSD type file permission schemr using set GID trick to the mount point directory as root only when you start using it. $ sudo chmod 5775 /mount/point/ Let each system mount it automatically. Does not this work for you? > What's the best FS for sharing data between unrelated Linux systems? Is > it really FAT or NTFS? > > Thanks, > Christoph > > > -- > To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org > with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org > Archive: http://lists.debian.org/87hb55ku8x@falma.de -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20110905152202.ga15...@debian.org
