* Re: usage pattern: xfsrestore to mirror disks
2007-07-08 18:18 usage pattern: xfsrestore to mirror disks Jakob Praher
@ 2007-07-09 5:03 ` Timothy Shimmin
2007-07-10 19:24 ` Jakob Praher
0 siblings, 1 reply; 4+ messages in thread
From: Timothy Shimmin @ 2007-07-09 5:03 UTC (permalink / raw)
To: Jakob Praher; +Cc: linux-xfs
[-- Attachment #1: Type: text/plain, Size: 1917 bytes --]
Hi Jakob,
Jakob Praher wrote:
> hi all,
>
> first of all: I am a very happy user of xfs for a long time now.
> I use xfs in tandem with lvm2 and I have to say I am very pleased.
>
> Now a question:
>
> There are two modes of using xfs(dump,restore): non-cumulative and
> cumulative. Is this cumulative mode also good to work with full dumps
> (level0). E.g. the data I have to mirror is not large, and I don't want
> to rely on inventory data. So I want for instance if between two full
> dumps a file F was deleted, it should get deleted when I do xfsrestore
> for the second time.
>
> I don't keep the xfsdump output files but i just apply them via ssh. So
> something like that would be great!
>
> Maybe someone can shed some light on that.
>
The cumulative mode really only relates to restore and not xfsdump.
xfsrestore in cumulative mode keeps its version of the directory tree
around (restoredir/xfsrestorehousekeepingdir/tree) so that it can use
it to compare with and decide if directory entries have been renamed,
deleted etc.. The code has been written to do this given an initial
level 0 dump and then delta dumps (incremental or resumed).
If you try to use a 2nd level 0 dump on restore then it will fail to
work - it won't restore anything.
It fails in xfsdump/restore/content.c/dumpcompat() when it
compares the restores uuid from persp->a.lastdumpid with the
incremental's uuid stored in scrhdrp->cih_last_id (and for a full
dump the cih_last_id won't be set).
Unfortunatly, a flag is set in restore so that it stops it from reporting
this error (not sure why).
I tried circumventing this uuid check (see the patch) and things
seemed to work ok (it did the renames and deletes).
However, I'm uncertain of any other repercussions - it's been a while
since I looked at cumulative restores. Maybe others might know.
I wonder if other tools might be useful to you... xfscopy,...?
--Tim
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===========================================================================
Index: xfsdump/restore/content.c
===========================================================================
--- a/xfsdump/restore/content.c 2007-07-09 14:41:15.000000000 +1000
+++ b/xfsdump/restore/content.c 2007-07-09 14:36:54.000000000 +1000
@@ -2019,7 +2019,7 @@ content_stream_restore( ix_t thrdix )
} else if ( dumpcompat( resumepr,
level,
*baseidp,
- BOOL_FALSE )) {
+ BOOL_TRUE )) {
if ( uuid_compare( lastdumprejectedid,
grhdrp->gh_dumpid) == 0) {
matchpr = BOOL_FALSE;
@@ -6762,7 +6762,7 @@ dumpcompat( bool_t resumepr, ix_t level,
"selected dump not based on "
"previously applied dump\n"));
}
- return BOOL_FALSE;
+ /*return BOOL_FALSE;*/ return BOOL_TRUE;
}
}
}
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