how to access ZFS snapshot via iSCSI

[Zeus Panchenko]

hi all,

please, may somebody advice, can I access ZFS snapshot via iSCSI?

I do can get access to ZFS filesystem and zvol, but how to access ZFS snapshot?

I am trying that via istgt, in istgt.conf I put:

[LogicalUnit4]
  Comment "ZVOL 500Gb to test"
  TargetName zvol-totest
  Mapping PortalGroup1 InitiatorGroup1
  AuthMethod Auto
  AuthGroup AuthGroup1
  UseDigest Auto
  UnitType Disk
  QueueDepth 64
  LUN0 Storage /dev/zvol/storage/win/zvol-totest Auto

and I can mount it and use

when I put

[LogicalUnit5]
  Comment "snapshot of ZVOL 500Gb totest"
  TargetName zvol-totest-snapshot
  Mapping PortalGroup1 InitiatorGroup1
  AuthMethod Auto
  AuthGroup AuthGroup1
  UseDigest Auto
  UnitType Disk
  QueueDepth 64
  LUN0 Storage /dev/zvol/storage/win/zvol-totest at hourly-2012-09-26-11 Auto

and trying to restart istgt, I'm getting:

LU4 HDD UNIT
LU4: LUN0 file=/dev/zvol/storage/win/zvol-totest, size=536870912000
LU4: LUN0 1048576000 blocks, 512 bytes/block
LU4: LUN0 500.0GB storage for iqn.2007-09.jp.ne.peach.istgt:zvol-totest
LU4: LUN0 serial 10000004
LU4: LUN0 read cache enabled, write cache enabled
LU4: LUN0 command queuing enabled, depth 64
LU5 HDD UNIT
LU5: LUN0 file=/dev/zvol/storage/win/zvol-totest at hourly-2012-09-26-11, size=536870912000
LU5: LUN0 1048576000 blocks, 512 bytes/block
istgt_lu_disk.c: 642:istgt_lu_disk_init: ***ERROR*** LU5: LUN0: open error(errno=17)
istgt_lu.c:2091:istgt_lu_init_unit: ***ERROR*** LU5: lu_disk_init() failed
istgt_lu.c:2166:istgt_lu_init: ***ERROR*** LU5: lu_init_unit() failed
istgt.c:2799:main: ***ERROR*** istgt_lu_init() failed
/usr/local/etc/rc.d/istgt: WARNING: failed to start istgt


where am I wrong?

-- 
Zeus V. Panchenko				jid:zeus at im.ibs.dn.ua
IT Dpt., I.B.S. LLC					  GMT+2 (EET)