>From: Andreas Gruenbacher <agruen@xxxxxxx>
>> The inode and any thing like ACLs etc is always on disk, and
>> permission to look at the contents can be determined without the
>> contents being present. Once past this point, the data is discovered
>> to be offline and the HSM daemons are responsible for bringing it
>> back on line, they are the only ones who need to manipulate HSM
>> related metadata.
>
>I would define the online/offline flag part of the HSM metadata. Of
>course that piece of information could be stored as some an inode flag,
>separate from the rest of the metadata which lives in an extended
>attribute. Then the kernel only needs to access this flag, and only the
>user space process cares about the EA.
For XFS it isn't an online/offline flag; it's a bitmask that indicates which
DMAPI events should be triggered for various operations on that file. This
mask is store in the XFS inode.
Dean
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