OSX Lion: afsctool makes partition unbootable

Discussion in 'macOS' started by greno, May 7, 2012.

  1. greno, May 7, 2012
    Last edited: May 7, 2012

    greno macrumors newbie

    May 3, 2012
    I downloaded the latest afsctool and then used it to compress one of my Lion installation partitions.

    Number of HFS+ compressed files: 282978
    Total number of files: 302274
    Total number of folders: 76309
    Total number of items (number of files + number of folders): 378583
    Folder size (uncompressed; reported size by Mac OS 10.6+ Finder): 13808049564 bytes / 14.6 GB (gigabytes) / 13.6 GiB (gibibytes)
    Folder size (compressed - decmpfs xattr; reported size by Mac OS 10.0-10.5 Finder): 8720691978 bytes / 8.98 GB (gigabytes) / 8.37 GiB (gibibytes)
    Folder size (compressed): 8910985079 bytes / 9.17 GB (gigabytes) / 8.54 GiB (gibibytes)
    Compression savings: 35.5%
    Approximate total folder size (files + file overhead + folder overhead): 9355235942 bytes / 9.36 GB (gigabytes) / 8.71 GiB (gibibytes)
    It compressed the partition but afterwards the partition was no longer bootable.

    It now showed up in the list of bootable partitions as EFI Boot instead of its regular name.

    So I decompressed the partition using afsctool and it again become bootable and its regular name showed up in the list of bootable partitions.

    So then I just tried compressing the System/ directory and once again the partition became unbootable.

    So apparently there is something that should not be compressed under System/ directory when using afsctool.

    Does anyone have any ideas about how to successfully compress an entire partition that will remain bootable using afsctool?

  2. FernandoPabon macrumors newbie

    Jun 25, 2012
    The file /System/Library/CoreServices/boot.efi shouldn't be compressed, the EFI bootloader wouldn't know how to uncompress and load it.

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