When you enter the realm of hardware errors, anything can happen. If
you are lucky you will see the same hard and soft errors every time you
cross a bad sector, but I have seen many cases wildly varying block
numbers on really sick disks. And yes, bad cables and USB interfaces
can be a problem too. Try wiggling the cable disk the disk stable and
see if you can produce errors.
Try doing a read with that USB hardware on another disk, too. That will
tell you something. I'll bet that the disk is bad. If it stops
producing errors, don't forgive it! Get a new one.
--STeve Andre'
On 01/06/18 21:45, Maximilian Pichler wrote:
Hi,
I'm running fsck on an external USB hard drive, using OpenBSD 6.2
inside VirtualBox on MacOS.
On each run it gives a handful of "CANNOT READ: BLK ..." messages, but
the block numbers reported are different (!) each time.
If the disk is damaged, shouldn't the problematic blocks be
consistent? Does this point to a communication problem with the disk
(e.g. faulty USB cable)? Or is this a hopelessly unstable situation
given the general screwiness of USB over VirtualBox/Mac OS...?
Also, does answering "y" to "CANNOT READ" modify the disk contents?
Thanks for any insights!
Max
xhci0 at pci0 dev 12 function 0 "Intel 7 Series xHCI" rev 0x00: apic 2 int 20
usb0 at xhci0: USB revision 3.0
uhub0 at usb0 configuration 1 interface 0 "Intel xHCI root hub" rev
3.00/1.00 addr 1
umass0 at uhub0 port 9 configuration 1 interface 0 "Seagate Expansion"
rev 3.00/0.00 addr 2
umass0: using SCSI over Bulk-Only
scsibus4 at umass0: 2 targets, initiator 0
sd0 at scsibus4 targ 1 lun 0: <Seagate, Expansion, 9300> SCSI4 0/direct fixed
sd0: 3815447MB, 512 bytes/sector, 7814037167 sectors
$ doas fsck /dev/sd0a
** /dev/rsd0a
** Last Mounted on /home/max/mnt
** Phase 1 - Check Blocks and Sizes
CANNOT READ: BLK 4235468160
CONTINUE? [Fyn?] y
THE FOLLOWING DISK SECTORS COULD NOT BE READ:
CANNOT READ: BLK 4128081280
CONTINUE? [Fyn?] y
THE FOLLOWING DISK SECTORS COULD NOT BE READ:
CANNOT READ: BLK 4194986880
CONTINUE? [Fyn?] y
CONTINUE? [Fyn?] y
THE FOLLOWING DISK SECTORS COULD NOT BE READ:
** Phase 2 - Check Pathnames
CANNOT READ: BLK 4195146384
CONTINUE? [Fyn?] y
CONTINUE? [Fyn?] y
THE FOLLOWING DISK SECTORS COULD NOT BE READ:
** Phase 3 - Check Connectivity
** Phase 4 - Check Reference Counts
** Phase 5 - Check Cyl groups
614222 files, 408012667 used, 76524122 free (3658 frags, 9565058
blocks, 0.0% fragmentation)
MARK FILE SYSTEM CLEAN? [Fyn?] y
***** FILE SYSTEM WAS MODIFIED *****
$ doas fsck -f /dev/sd0a
** /dev/rsd0a
** File system is already clean
** Last Mounted on /home/max/mnt
** Phase 1 - Check Blocks and Sizes
CANNOT READ: BLK 4236615424
CONTINUE? [Fyn?] y
THE FOLLOWING DISK SECTORS COULD NOT BE READ:
** Phase 2 - Check Pathnames
CANNOT READ: BLK 3732315520
CONTINUE? [Fyn?] y
THE FOLLOWING DISK SECTORS COULD NOT BE READ:
CANNOT READ: BLK 4161885792
CONTINUE? [Fyn?] y
THE FOLLOWING DISK SECTORS COULD NOT BE READ:
CANNOT READ: BLK 4201995728
CONTINUE? [Fyn?] y
THE FOLLOWING DISK SECTORS COULD NOT BE READ:
CANNOT READ: BLK 4202008160
CONTINUE? [Fyn?] y
THE FOLLOWING DISK SECTORS COULD NOT BE READ:
CANNOT READ: BLK 4202013680
CONTINUE? [Fyn?] y
THE FOLLOWING DISK SECTORS COULD NOT BE READ:
** Phase 3 - Check Connectivity
** Phase 4 - Check Reference Counts
** Phase 5 - Check Cyl groups
CANNOT READ: BLK 5011229824
CONTINUE? [Fyn?] y
THE FOLLOWING DISK SECTORS COULD NOT BE READ:
614222 files, 408012667 used, 76524122 free (3658 frags, 9565058
blocks, 0.0% fragmentation)