On Fri, Jan 07, 2011 at 03:04:02PM +0100, René Nussbaumer wrote:
> ---
> lib/cmdlib.py | 34 ++++++++++++++++++++++------------
> 1 files changed, 22 insertions(+), 12 deletions(-)
>
> diff --git a/lib/cmdlib.py b/lib/cmdlib.py
> index d80c0da..3b6064f 100644
> --- a/lib/cmdlib.py
> +++ b/lib/cmdlib.py
> @@ -6504,6 +6504,10 @@ def _WipeDisks(lu, instance):
> for idx, device in enumerate(instance.disks):
> lu.LogInfo("* Wiping disk %d", idx)
> logging.info("Wiping disk %d for instance %s", idx, instance.name)
> + logging.info("Pause sync of disk %d for instance %s", idx, instance.name)
> +
> + result = lu.rpc.call_blockdev_pause_resume_sync(node, device, True)
> + result.Raise("Could not pause sync of disk %d" % idx)
>
> # The wipe size is MIN_WIPE_CHUNK_PERCENT % of the instance disk but
> # MAX_WIPE_CHUNK at max
> @@ -6515,18 +6519,24 @@ def _WipeDisks(lu, instance):
> last_output = 0
> start_time = time.time()
>
> - while offset < size:
> - wipe_size = min(wipe_chunk_size, size - offset)
> - result = lu.rpc.call_blockdev_wipe(node, device, offset, wipe_size)
> - result.Raise("Could not wipe disk %d at offset %d for size %d" %
> - (idx, offset, wipe_size))
> - now = time.time()
> - offset += wipe_size
> - if now - last_output >= 60:
> - eta = _CalcEta(now - start_time, offset, size)
> - lu.LogInfo(" - done: %.1f%% ETA: %s" %
> - (offset / float(size) * 100, utils.FormatSeconds(eta)))
> - last_output = now
> + try:
> + while offset < size:
> + wipe_size = min(wipe_chunk_size, size - offset)
> + result = lu.rpc.call_blockdev_wipe(node, device, offset, wipe_size)
> + result.Raise("Could not wipe disk %d at offset %d for size %d" %
> + (idx, offset, wipe_size))
> + now = time.time()
> + offset += wipe_size
> + if now - last_output >= 60:
> + eta = _CalcEta(now - start_time, offset, size)
> + lu.LogInfo(" - done: %.1f%% ETA: %s" %
> + (offset / float(size) * 100, utils.FormatSeconds(eta)))
> + last_output = now
> + finally:
> + logging.info("Resume sync of disk %d for instance %s", idx,
> instance.name)
> +
> + result = lu.rpc.call_blockdev_pause_resume_sync(node, device, False)
> + result.Raise("Could not resume sync of disk %d" % idx)
The patch looks OK, however…
For some time now, we have a known bug about --early-release and node
overloading. The fix for that would be to write a small daemon that
watches the DRBD syncs and orders pause/resumes as appropriate so that
only N drbd resyncs per node are running.
If Ganeti starts issuing per-device pause/resume, independently for each
instance, that means we can no longer control globally the resync
process.
So my question is it wouldn't be better to change this whole
architecture as follows:
1. create LV on primary node
2. wipe it
3. and only then create the DRBD devices
Optionally, the install could move to step 2B, so that it doesn't need
to replicate the data to the remote node twice.
What do you think?
iustin
