Hi, I'm trying to find a solution to the following scenario - I want to have an L4Linux instance running (from a CD) where the root filesystem is several hundred MB's big, so it is not feasible to run it from a ramdisk (the filesystem is larger than the amount of RAM available) - I need to run it directly from the CD. A possible solution I'm thinkning about is to give the L4Linux instance access to the CD-ROM drive, then store a SquashFS image as a file on the drive and UnionFS it with a tmpfs when the system starts. Now here's the catch - While this solution may technically work, it is still not 'good enough' because I can't give the L4Linux instance direct access to the CD-ROM drive - I need to have it completely isolated so a user working on the L4Linux instance will not have access to any files stored on the CD (other than the SquashFS image) even if he/she has root access over the L4Linux instance. I was thinking - is it possible to specify the SquashFS image as an L4 module and then somehow mount it from within L4Linux in-place (i.e. without completely loading it to RAM)? Is there any other way to accomplish what's needed in this scenario?
Thank you all, Dan.
Hi,
On Sun Mar 06, 2011 at 18:45:49 +0200, Dan Haim wrote:
I'm trying to find a solution to the following scenario - I want to have an L4Linux instance running (from a CD) where the root filesystem is several hundred MB's big, so it is not feasible to run it from a ramdisk (the filesystem is larger than the amount of RAM available) - I need to run it directly from the CD. A possible solution I'm thinkning about is to give the L4Linux instance access to the CD-ROM drive, then store a SquashFS image as a file on the drive and UnionFS it with a tmpfs when the system starts. Now here's the catch - While this solution may technically work, it is still not 'good enough' because I can't give the L4Linux instance direct access to the CD-ROM drive - I need to have it completely isolated so a user working on the L4Linux instance will not have access to any files stored on the CD (other than the SquashFS image) even if he/she has root access over the L4Linux instance. I was thinking - is it possible to specify the SquashFS image as an L4 module and then somehow mount it from within L4Linux in-place (i.e. without completely loading it to RAM)? Is there any other way to accomplish what's needed in this scenario?
If the image is not loaded into RAM upon boot you'll need a driver for the CD-ROM somewhere. Of course, L4Linux is a convenience place to have that driver in. If that is not possible another L4Linux could be used that drives the CD-ROM and both are connected via virtual network. Would that second L4Linux be acceptable in your setup?
Adam
Hi, If I include the CD-ROM driver in L4Linux then that would allow it complete access to all files stored on the CD, wouln't it? Anyway since I sent the previous mail yesterday I've already thought of the second instance w/ virtual network solution (great minds think alike, right?) but I was hoping for a more direct approach.
Anyway, many thanks!
-----Original Message----- From: l4-hackers-bounces@os.inf.tu-dresden.de [mailto:l4-hackers-bounces@os.inf.tu-dresden.de] On Behalf Of Adam Lackorzynski Sent: Monday, March 07, 2011 12:16 PM To: l4-hackers@os.inf.tu-dresden.de Subject: Re: Can L4 modules be accessed as files from L4Linux?
Hi,
On Sun Mar 06, 2011 at 18:45:49 +0200, Dan Haim wrote:
I'm trying to find a solution to the following scenario - I want to have an L4Linux instance running (from a CD) where the root filesystem is several hundred MB's big, so it is not feasible to run it from a ramdisk (the filesystem is larger than the amount of RAM available) - I need to run it directly from the CD. A possible solution I'm thinkning about is to give the L4Linux instance access to the CD-ROM drive, then store a SquashFS image as a file on the drive and UnionFS it with a tmpfs when the system starts. Now here's the catch - While this solution may technically work, it is still not 'good enough' because I can't give the L4Linux instance direct access to the CD-ROM drive - I need to have it completely isolated so a user working on the L4Linux instance will not have access to any files stored on the CD (other than the SquashFS image) even if he/she has root access over the L4Linux instance. I was thinking - is it possible to specify the SquashFS image as an L4 module and then somehow mount it from within L4Linux in-place (i.e. without completely loading it to RAM)? Is there any other way to accomplish what's needed in this scenario?
If the image is not loaded into RAM upon boot you'll need a driver for the CD-ROM somewhere. Of course, L4Linux is a convenience place to have that driver in. If that is not possible another L4Linux could be used that drives the CD-ROM and both are connected via virtual network. Would that second L4Linux be acceptable in your setup?
Adam
l4-hackers@os.inf.tu-dresden.de
-
Adam Lackorzynski -
Dan Haim