[sheepdog-users] about snapshot and backup

[Valerio Pachera]

Sheepdog daemon version 0.6.1

# collie vdi list
  Name        Id    Size    Used  Shared    Creation time   VDI id  Copies  Tag
  big          0   50 GB  0.0 MB  0.0 MB 2013-08-20 14:16   4fd259
2
  wheezy_template     0   10 GB  4.5 GB  0.0 MB 2013-08-20 11:31
5ddf88     2
s small        2  1.0 GB  148 MB  552 MB 2013-08-20 14:39   98998d
2
s small        3  1.0 GB  136 MB  564 MB 2013-08-20 15:09   98998e
2
s small        4  1.0 GB  144 MB  556 MB 2013-08-20 15:09   98998f
2
s small        5  1.0 GB  132 MB  568 MB 2013-08-20 15:10   989990
2
s small        6  1.0 GB   44 MB  660 MB 2013-08-20 15:10   989991
2
  small        0  1.0 GB  0.0 MB  704 MB 2013-08-20 15:17   989992     2

# qemu-img convert -O qcow2 sheepdog:small:2 backup/small_bkp.qcow2
# collie vdi backup -s 3 -F 2 small > backup/snap_2_3.img
# collie vdi backup -s 4 -F 3 small > backup/snap_3_4.img
# collie vdi backup -s 5 -F 4 small > backup/snap_4_5.img

# ls -lh backup/
totale 7,4M
-rw-r--r-- 1 root root 7,4M ago 20 15:26 small_bkp.qcow2
-rw-r--r-- 1 root root  29K ago 20 15:15 snap_2_3.img
-rw-r--r-- 1 root root  54K ago 20 15:16 snap_3_4.img
-rw-r--r-- 1 root root  26K ago 20 15:17 snap_4_5.img

root at test004:~# collie vdi delete -s 5 small
root at test004:~# collie vdi delete -s 4 small
root at test004:~# collie vdi delete -s 3 small
root at test004:~# collie vdi delete -s 2 small
root at test004:~# collie vdi delete  small

RESTORE

qemu-img convert -f qcow2 backup/small_bkp.qcow2 sheepdog:small
...
qemu-img: cannot find aio_req 0
qemu-img: cannot find aio_req 0
qemu-img: cannot find aio_req 0
qemu-img: cannot find aio_req 0
qemu-img: cannot find aio_req 0
qemu-img: cannot find aio_req 0
...

sheep.log

Aug 20 15:29:07 [gway 19865] add_to_lru_cache(721) PANIC: the object
already exist
Aug 20 15:29:07 [gway 19865] crash_handler(180) sheep exits
unexpectedly (Aborted).
Aug 20 15:29:07 [gway 19865] sd_backtrace(845) sheep.c:182: crash_handler
Aug 20 15:29:07 [gway 19865] sd_backtrace(859)
/lib/x86_64-linux-gnu/libpthread.so.0(+0xf02f) [0x7fe9faf8402f]
Aug 20 15:29:07 [gway 19865] sd_backtrace(859)
/lib/x86_64-linux-gnu/libc.so.6(gsignal+0x34) [0x7fe9fa590474]
Aug 20 15:29:07 [gway 19865] sd_backtrace(859)
/lib/x86_64-linux-gnu/libc.so.6(abort+0x17f) [0x7fe9fa5936ef]
Aug 20 15:29:07 [gway 19865] sd_backtrace(845) object_cache.c:721:
add_to_lru_cache
Aug 20 15:29:07 [gway 19865] sd_backtrace(845) object_cache.c:771:
object_cache_lookup
Aug 20 15:29:07 [gway 19865] sd_backtrace(845) object_cache.c:1130:
object_cache_handle_request
Aug 20 15:29:07 [gway 19865] sd_backtrace(845) ops.c:1385: do_process_work
Aug 20 15:29:07 [gway 19865] sd_backtrace(845) work.c:243: worker_routine
Aug 20 15:29:07 [gway 19865] sd_backtrace(859)
/lib/x86_64-linux-gnu/libpthread.so.0(+0x6b4f) [0x7fe9faf7bb4f]
Aug 20 15:29:07 [gway 19865] sd_backtrace(859)
/lib/x86_64-linux-gnu/libc.so.6(clone+0x6c) [0x7fe9fa638a7c]
Aug 20 15:29:07 [gway 19865] dump_stack_frames(755) cannot find gdb
Aug 20 15:29:07 [gway 19865] __sd_dump_variable(709) cannot find gdb
Aug 20 15:29:07 [main] crash_handler(487) sheep pid 19051 exited unexpectedly.

---

My intention was to restore the snapshot once restored the vdi but I
didn't get there.

By the way, I think the files I got from 'vdi backup' are way to small.
So I doubt it would have worked out.