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Thread: Partition does not start on physical sector boundary.

  1. #1
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    Default Partition does not start on physical sector boundary.

    Bought a new hard drive. Partitioned and formatted it using cylinder boundaries and ext4. Installed Leap 42.3. Then fdisk warns me...
    Code:
    Device     Boot     Start        End    Sectors   Size Id Type
    /dev/sdb1              63    8193149    8193087   3.9G 82 Linux swap / Solaris
    /dev/sdb2  *      8193150   69625709   61432560  29.3G 83 Linux
    /dev/sdb3        69625710  131058269   61432560  29.3G 83 Linux
    /dev/sdb4       131058270 1953520064 1822461795   869G  5 Extended
    /dev/sdb5       131058333  151541144   20482812   9.8G 83 Linux
    /dev/sdb6       151541208  172024019   20482812   9.8G 83 Linux
    /dev/sdb7       172024083  909311129  737287047 351.6G 83 Linux
    
    
    Partition 1 does not start on physical sector boundary.
    Partition 2 does not start on physical sector boundary.
    Partition 3 does not start on physical sector boundary.
    Partition 4 does not start on physical sector boundary.
    Partition 5 does not start on physical sector boundary.
    Partition 7 does not start on physical sector boundary.
    Is there a simple solution? Thanks in advance.

  2. #2
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    Default Re: Partition does not start on physical sector boundary.

    This happens most often if you didn't format the disk (maybe you only thought you did, did you wipe the disk and re-partition the disk?).
    If a disk is partitioned using a Windows utility, the file system is offset and not aligned exactly on the partition.
    AFAIK every non-Windows utility will align the file system exactly with your partition boundaries.

    Depending on what you do,
    This may or may not be a critical problem since your physical disk blocks are 256k or larger (in multiples of 256k), and every file system and file system overlay has to align with what exists below it or you could have major performance degradation.

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  3. #3
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    Default Re: Partition does not start on physical sector boundary.

    Quote Originally Posted by ionmich View Post
    Partitioned and formatted it using cylinder boundaries and ext4.
    There's your problem. Cylinder boundaries are pretty much obsolete. It is usual to partition at 1M (or 2048 sector) boundaries.

    Yes, there is still a geometry in terms of cylinders/track/sectors. But it is pretty much artificial. The geometry is there because older software uses it. In your case, the start of a logical cylinder isn't even the start of a physical sector.
    openSUSE Leap 15.3; KDE Plasma 5.18.6;

  4. #4
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    Default Re: Partition does not start on physical sector boundary.

    Quote Originally Posted by ionmich View Post
    B
    Is there a simple solution?
    No. You need to re-partition.

    OTOH I doubt you will notice the difference in real life unless you intend to run very disk-intensive workload.

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    Default Re: Partition does not start on physical sector boundary.

    Quote Originally Posted by nrickert View Post
    There's your problem. Cylinder boundaries are pretty much obsolete. It is usual to partition at 1M (or 2048 sector) boundaries.

    Yes, there is still a geometry in terms of cylinders/track/sectors. But it is pretty much artificial. The geometry is there because older software uses it. In your case, the start of a logical cylinder isn't even the start of a physical sector.
    Thanks. I re-formatted and re-installed and all is well.

  6. #6
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    Default Re: Partition does not start on physical sector boundary.

    Quote Originally Posted by arvidjaar View Post
    No. You need to re-partition.

    OTOH I doubt you will notice the difference in real life unless you intend to run very disk-intensive workload.
    I wish I had read this post before I re-formatted and re-installed. Thanks anyway.

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