can't mount ISO on loop

[David Chmelik]

On Slackware64 15+current, I can no longer mount ISOs on loopback.

***@cosmos:~# mount ware/slackware/slackware64-15.0-iso/slackware64-15.0-
install-dvd.iso /scd -o loop
mount: /scd: can't read superblock on /dev/loop0.

[Henrik Carlqvist]

Post by David Chmelik
On Slackware64 15+current, I can no longer mount ISOs on loopback.
ware/slackware/slackware64-15.0-iso/slackware64-15.0-
install-dvd.iso /scd -o loop mount: /scd: can't read superblock on
/dev/loop0.

What does

file ware/slackware/slackware64-15.0-iso/slackware64-15.0-install-dvd.iso

say?

I don't think that it does matter, but if the iso file seems OK I would
try to put the options before the device and mount point on the command
line:

mount -o loop ware/slackware/slackware64-15.0-iso/slackware64-15.0-
install-dvd.iso /scd

regards Henrik

[David Chmelik]

Post by Henrik Carlqvist

Post by David Chmelik
On Slackware64 15+current, I can no longer mount ISOs on loopback.
ware/slackware/slackware64-15.0-iso/slackware64-15.0- install-dvd.iso
/scd -o loop mount: /scd: can't read superblock on /dev/loop0.

What does
file
ware/slackware/slackware64-15.0-iso/slackware64-15.0-install-dvd.iso
say?

***@cosmos:~# file ware/slackware/slackware64-15.0-iso/slackware64-15.0-
install-dvd.iso
ware/slackware/slackware64-15.0-iso/slackware64-15.0-install-dvd.iso: ISO
9660 CD-ROM filesystem data (DOS/MBR boot sector) 'SlackDVD' (bootable)

Post by Henrik Carlqvist
I don't think that it does matter, but if the iso file seems OK I would
try to put the options before the device and mount point on the command
mount -o loop ware/slackware/slackware64-15.0-iso/slackware64-15.0-
install-dvd.iso /scd

It doesn't matter for that command; I originally learned to put '-o loop'
afterwards but you can put it before also.
The same thing happens with all ISOs.

[Rich]

Post by David Chmelik

Post by Henrik Carlqvist

Post by David Chmelik
On Slackware64 15+current, I can no longer mount ISOs on loopback.
ware/slackware/slackware64-15.0-iso/slackware64-15.0- install-dvd.iso
/scd -o loop mount: /scd: can't read superblock on /dev/loop0.

What does
file
ware/slackware/slackware64-15.0-iso/slackware64-15.0-install-dvd.iso
say?

install-dvd.iso
ware/slackware/slackware64-15.0-iso/slackware64-15.0-install-dvd.iso: ISO
9660 CD-ROM filesystem data (DOS/MBR boot sector) 'SlackDVD' (bootable)

Post by Henrik Carlqvist
I don't think that it does matter, but if the iso file seems OK I would
try to put the options before the device and mount point on the command
mount -o loop ware/slackware/slackware64-15.0-iso/slackware64-15.0-
install-dvd.iso /scd

It doesn't matter for that command; I originally learned to put '-o loop'
afterwards but you can put it before also.
The same thing happens with all ISOs.

Can you loop mount manually, then mount the loop device?

I.e.:

# losetup --find --show ware/slackware/slackware64-15.0-iso/slackware64-15.0-install-dvd.iso
/dev/loop0
# mount /dev/loop0 /scd

The /dev/loop0 will change depending upon what else is already mounted,
you need to use the value returned by losetup for the mount.

When done, you have to unmount, then remove the loop device:

# umount /scd
# losetup -d /dev/loop0

See the man page for losetup for details of other options.

[Mike Small]

Post by David Chmelik
On Slackware64 15+current, I can no longer mount ISOs on loopback.
install-dvd.iso /scd -o loop
mount: /scd: can't read superblock on /dev/loop0.

Does it help to explicitly pass the iso9660 type to mount (-t option)?

- Mike Sm.

[John McCue]

Post by David Chmelik
On Slackware64 15+current, I can no longer mount ISOs on loopback.
install-dvd.iso /scd -o loop
mount: /scd: can't read superblock on /dev/loop0.

For the Slackware 15 ISO, I cam mount it doing:

sudo mount -t iso9660 -o ro,loop <ISO-File> <mount-point>

As someone else suggested, maybe the iso9660 is needed.

HTH

[Bit Twister]

Post by John McCue

Post by David Chmelik
On Slackware64 15+current, I can no longer mount ISOs on loopback.
install-dvd.iso /scd -o loop
mount: /scd: can't read superblock on /dev/loop0.

sudo mount -t iso9660 -o ro,loop <ISO-File> <mount-point>
As someone else suggested, maybe the iso9660 is needed.

I always use auto, Example:
mount -t auto -o ro,loop image.iso /mnt/cdrom

[Alexander Grotewohl]

Post by Bit Twister

Post by John McCue

Post by David Chmelik
On Slackware64 15+current, I can no longer mount ISOs on loopback.
ware/slackware/slackware64-15.0-iso/slackware64-15.0-
install-dvd.iso /scd -o loop mount: /scd: can't read superblock on
/dev/loop0.

sudo mount -t iso9660 -o ro,loop <ISO-File> <mount-point>
As someone else suggested, maybe the iso9660 is needed.

mount -t auto -o ro,loop image.iso /mnt/cdrom

Even easier (as root):

mount /mnt/storage-b/iso/Linux/slackware64-current-install-
dvd.iso /mnt/cdrom

Does the right thing.

[bad sector]

Post by David Chmelik
On Slackware64 15+current, I can no longer mount ISOs on loopback.
install-dvd.iso /scd -o loop
mount: /scd: can't read superblock on /dev/loop0.

using the same file, in Slackware-15.0:

# mount -o loop /0/dx/iso/slackware64-15.0-install-dvd.iso /mnt;ls /mnt
mount: /mnt: WARNING: source write-protected, mounted read-only.
ANNOUNCE.15.0 CRYPTO_NOTICE.TXT README.initrd SPEAK_INSTALL.TXT patches
CHANGES_AND_HINTS.TXT ChangeLog.txt README_CRYPT.TXT Slackware-HOWTO slackware64
CHECKSUMS.md5 EFI README_LVM.TXT UPGRADE.TXT testing
CHECKSUMS.md5.asc FILELIST.TXT README_RAID.TXT extra usb-and-pxe-installers
COPYING GPG-KEY README_UEFI.TXT isolinux
COPYING3 PACKAGES.TXT RELEASE_NOTES kernels
COPYRIGHT.TXT README.TXT SPEAKUP_DOCS.TXT pasture

I would check the file and maybe try a couple of other mountpoints

[David Chmelik]

Post by David Chmelik
On Slackware64 15+current, I can no longer mount ISOs on loopback.
ware/slackware/slackware64-15.0-iso/slackware64-15.0-
install-dvd.iso /scd -o loop mount: /scd: can't read superblock on
/dev/loop0.

I had to 'zpool scrub home,' and then it worked.
If one replies, it's good to read previous replies. Someone didn't,
then suggested something already resolved.

[Henrik Carlqvist]

Post by David Chmelik

Post by David Chmelik
On Slackware64 15+current, I can no longer mount ISOs on loopback.
ware/slackware/slackware64-15.0-iso/slackware64-15.0- install-dvd.iso
/scd -o loop mount: /scd: can't read superblock on /dev/loop0.

I had to 'zpool scrub home,' and then it worked.
If one replies, it's good to read previous replies. Someone didn't,
then suggested something already resolved.

I have no experience from zfs myself, but if I understand this solution
correctly you had your iso file on a zfs file system which somehow got
corrupted and needed fixing for you to be able to read the entire iso
file?

regards Henrik

[David Chmelik]

Post by Henrik Carlqvist

Post by David Chmelik

Post by David Chmelik
On Slackware64 15+current, I can no longer mount ISOs on loopback.
ware/slackware/slackware64-15.0-iso/slackware64-15.0- install-dvd.iso
/scd -o loop mount: /scd: can't read superblock on /dev/loop0.

I had to 'zpool scrub home,' and then it worked.
If one replies, it's good to read previous replies. Someone didn't,
then suggested something already resolved.

I have no experience from zfs myself, but if I understand this solution
correctly you had your iso file on a zfs file system which somehow got
corrupted and needed fixing for you to be able to read the entire iso
file?

Either that or because ZFS is broken in Linux kernel 5.16.n; I had to
switch back to 5.15.n (and when you boot if there's a problem it scrubs
anyway... I'm not sure that was really the problem but I was told to do
so,)