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Question on Disk Layout (Stacking supported ?)

Hello list, 
I have a more general question regarding dm_crypt. 
  Q: What is the best way to incorporate dm_crypt in a production ready device stack ? 

Summing I have multipathing (optional) and I want flexible storage management with pvresize, multiple filesystems and everything (e.g. in "the clouds") LVM is the way to go. So my ideal (and working) setup would look like this: 
Filesystem: [      /boot      ] [ /   ]  [ /var ]
LVM         [                 ] [ lv1 ]  [ lv2  ]
LVM         [                 ] [ vg (RootVG)   ]
LVM         [                 ] [ pv            ]
Crypt:      [                 ] [ DM_CRYPT      ] 
Partition:  [ part1 - (boot)  ] [    part2      ]
SCSI:       [            Block Device           ] 
DMMP:       [   Path1         ][    Path2       ]  (Optional Layer)
Disk:       [            LUN                    ] 
Do you see any problems (from the dm_crypt side) with this setup in terms of deadlocks, or unsupported stacking  or is this a "supposed to work" configuration ? 

I know that device mapper always causes performance penalty because of missing barrier support (earlier Kernels) and I/O splitting in 4k units, however I have a BBU, so not a problem really and performance penalty is allowed.

I have seen that the split to 4k causes latency to increase dramatically, however this seems to be a "minor" issue also (altought no solution so far).

Mit freundlichen Grüßen / Kind Regards
Robert Heinzmann
dm-crypt mailing list

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