On Fri, 2014-01-31 at 16:54 +0800, Jeff Liu wrote: > Hello, > > On 01/31 2014 15:40 PM, Sun_Blood wrote: > > Hello, > > > > If I understands it correctly XFS don't have a limit to the size of > > extended attributes(EA) but Linux impose a limit at 64k. > > What I am trying to do is build a backup server that our Apple computers > > will use together with rsync to backup files to. The problem I face is > > that Apple HFS+ don't have a limit to EA so it has files with more then > > 64k of EA in it. Technical Note TN1150: "In an HFS Plus B-tree, the node size is determined by a field (nodeSize) in the header node. The node size must be a power from 512 through 32,768." So, as minimum, xattrs unable to be a larger than node size. But xattrs' size has limitation anyway: https://github.com/darwin-on-arm/xnu/blob/master/bsd/hfs/hfs.h#L849 /* Maximum extended attribute size supported for all extended attributes except * resource fork and finder info. */ #define HFS_XATTR_MAXSIZE (128 * 1024) So, I need to check and correct slightly HFS+ xattrs support code. Because, I used 3082 bytes limitation value. Thanks, Vyacheslav Dubeyko. > > > > The Linux Kernel has a limit imposed to it in include/linux/limits.h > > > > #defineXATTR_SIZE_MAX 65536 /* size of an extended attribute value > > (64k) */ > > > > #defineXATTR_LIST_MAX 65536 /* size of extended attribute namelist > > (64k) */ > > > > Yes, 64k is the VFS limit per EA value size. > > Changing this values feels unsafe because they will be system wide. > > > > Is the any possibility to combine Linux + XFS to make a backup that > > works with EA or is this more a question for kernel.org <http://kernel.org>? > > So if an EA value size on HFS+ is larger than 64k, I suspect it would failed to preserve > on Linux+XFS... But if a file has multiple EAs, and each EA's value size is <= 64K, it > would be works IMO. > > Thanks, > -Jeff > > _______________________________________________ > xfs mailing list > xfs@xxxxxxxxxxx > http://oss.sgi.com/mailman/listinfo/xfs _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
