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On 04/30 10:55, Wols Lists wrote: |
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> On 30/04/20 10:32, tuxic@××××××.de wrote: |
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> > Hi, |
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> > |
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> > recently I switched from the old MBR-scheme to GPT on |
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> > my new PC. |
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> > |
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> > I have two external USB-harddisk, which were partioned/formatted with |
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> > a MBR-scheme/MSDOS partition (but were never used to boot from. They are pure |
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> > data containers). |
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> > |
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> > When I connect these to my new PC, only the device is shown: |
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> > /dev/sdb, /dev/sdc. |
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> > |
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> > The kernel is configured (beside other things) as follows: |
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> > |
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> > # |
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> > # Partition Types |
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> > # |
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> > CONFIG_PARTITION_ADVANCED=y |
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> > # CONFIG_ACORN_PARTITION is not set |
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> > # CONFIG_AIX_PARTITION is not set |
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> > # CONFIG_OSF_PARTITION is not set |
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> > # CONFIG_AMIGA_PARTITION is not set |
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> > # CONFIG_ATARI_PARTITION is not set |
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> > # CONFIG_MAC_PARTITION is not set |
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> > CONFIG_MSDOS_PARTITION=y |
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> > # CONFIG_BSD_DISKLABEL is not set |
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> > # CONFIG_MINIX_SUBPARTITION is not set |
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> > # CONFIG_SOLARIS_X86_PARTITION is not set |
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> > # CONFIG_UNIXWARE_DISKLABEL is not set |
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> > # CONFIG_LDM_PARTITION is not set |
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> > # CONFIG_SGI_PARTITION is not set |
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> > # CONFIG_ULTRIX_PARTITION is not set |
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> > # CONFIG_SUN_PARTITION is not set |
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> > # CONFIG_KARMA_PARTITION is not set |
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> > CONFIG_EFI_PARTITION=y |
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> > # CONFIG_SYSV68_PARTITION is not set |
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> > # CONFIG_CMDLINE_PARTITION is not set |
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> > # end of Partition Types |
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> > |
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> > CONFIG_BLOCK_COMPAT=y |
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> > CONFIG_BLK_MQ_PCI=y |
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> > CONFIG_BLK_MQ_VIRTIO=y |
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> > CONFIG_BLK_PM=y |
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> > |
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> > dmesg shows this: |
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> > [14617.672363] usb 2-2: New USB device found, idVendor=1058, idProduct=25a2, bcdDevice=10.21 |
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> > [14617.672364] usb 2-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3 |
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> > [14617.672364] usb 2-2: Product: Elements 25A2 |
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> > [14617.672365] usb 2-2: Manufacturer: Western Digital |
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> > [14617.672366] usb 2-2: SerialNumber: 575844314132383959393934 |
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> > [14617.681660] usb-storage 2-2:1.0: USB Mass Storage device detected |
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> > [14617.681737] scsi host10: usb-storage 2-2:1.0 |
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> > [14618.725450] scsi 10:0:0:0: Direct-Access WD Elements 25A2 1021 PQ: 0 ANSI: 6 |
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> > [14618.725594] sd 10:0:0:0: Attached scsi generic sg1 type 0 |
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> > [14618.728090] sd 10:0:0:0: [sdb] Spinning up disk... |
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> > [14619.748918] ...ready |
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> > |
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> > I tried different USB ports in a desperate hope of success... |
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> > ...no, same problem. |
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> > |
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> > Interestingly fdisk shows the following: |
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> > |
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> > host> sudo fdisk -l /dev/sdb |
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> > Disk /dev/sdb: 931.49 GiB, 1000170586112 bytes, 1953458176 sectors |
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> > Disk model: Elements 25A2 |
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> > Units: sectors of 1 * 512 = 512 bytes |
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> > Sector size (logical/physical): 512 bytes / 512 bytes |
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> > I/O size (minimum/optimal): 512 bytes / 512 bytes |
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> |
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> This could be the key. Sector sizes have been changing from 512 to 4096 |
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> over many years. If your kernel has been updated to expect/use 4096 byte |
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> sectors, it might not be able to read the disk properly. |
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> |
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> > Disklabel type: dos |
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> > Disk identifier: 0x16f2a91f |
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> > |
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> > Device Boot Start End Sectors Size Id Type |
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> > /dev/sdb1 1 1953458175 1953458175 931.5G ee GPT |
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> > |
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> > The type is shown as GPT...but the drive has a MSDOS partition table. |
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> > |
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> > Reading my (old) internal harddrive with an external USB docking |
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> > station is possible without any problems, though. |
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> > |
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> > Unfortunatelu I have no space for 1T image of that drive -- otherwise |
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> > I would have made an image copy and experiment with that. |
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> > |
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> > So better ask, than sorry.... ;) |
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> > |
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> > Is this fixable or did I lost my backups? |
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> > |
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> Do you have access to an old kernel? |
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> |
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> The other thing is try using gdisk (or that could be fdisk under another |
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> name :-( But some partitioning schemes can write a GPT with protective |
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> MBR - if you can find something that will take the MBR and write it as a |
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> GPT that might help, too. |
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> |
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> Cheers, |
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> Wol |
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> |
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|
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Hi Wol, |
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|
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thank you for your posting! :) |
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|
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I switched to my new PC around 31.3.2020... |
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so there is no change "over the years" involved here...I think. |
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Where in the kernel this update is made? |
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I cannot remember to have configured such a thing manually... |
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|
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Changing the partitiontable in any way is risky to the data |
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I think...I am very unsure to do this. |
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I have access to an old kernel / system and can boot it. |
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But than I have the same problem another way around: I can |
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no longer access my new system ... due to the different |
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sector size.... |
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Are there any other ways to fix this problem? |
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|
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Cheers! |
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Meino |
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