Nir Soffer has uploaded a new change for review.
Change subject: multiapth: Disable hba rescanning by default ......................................................................
multiapth: Disable hba rescanning by default
Since commit 85d46e4572 we are scanning both iscsi bus and hbas when issuing multipath.rescan(). We did not find any bad effects when testing in our QE lab, but we have reports from customers that these rescans have bad effects on FC connections.
This patch disables hba rescanning by default, so users can use this feature if works for them, until we investigate this issue and provide better solution.
This should have been part of the original patch, since we cannot test all kinds of storage servers in the same setup and load used by all users. If hba rescanning cannot be used with certain storage server, it should be possible to disable this feature.
Change-Id: I812308e54ec2a9eab1ca4115e0456b2dd3990cfb Bug-Url: https://bugzilla.redhat.com/1152587 Signed-off-by: Nir Soffer nsoffer@redhat.com --- M lib/vdsm/config.py.in M vdsm/storage/multipath.py 2 files changed, 9 insertions(+), 1 deletion(-)
git pull ssh://gerrit.ovirt.org:29418/vdsm refs/changes/96/34196/1
diff --git a/lib/vdsm/config.py.in b/lib/vdsm/config.py.in index 01fcc12..b7963b7 100644 --- a/lib/vdsm/config.py.in +++ b/lib/vdsm/config.py.in @@ -246,6 +246,11 @@ ('vol_size_sample_interval', '60', 'How often should the volume size be checked (seconds).'),
+ ('hba_rescan', 'false', + 'Enable hba scanning when rescanning multipath. Required to ' + 'detect new or removed luns on FCP server. Disabled by default ' + 'since it may be disruptive.'), + ('scsi_rescan_minimal_timeout', '2', 'The minimum number of seconds to wait for scsi scan to return.'),
diff --git a/vdsm/storage/multipath.py b/vdsm/storage/multipath.py index bbf2fc8..3531850 100644 --- a/vdsm/storage/multipath.py +++ b/vdsm/storage/multipath.py @@ -32,6 +32,7 @@
from vdsm import constants from vdsm import utils +from vdsm.config import config import misc import iscsi import supervdsm @@ -104,7 +105,9 @@
# First rescan iSCSI and FCP connections iscsi.rescan() - supervdsm.getProxy().hbaRescan() + + if config.getboolean('irs', 'hba_rescan'): + supervdsm.getProxy().hbaRescan()
# Now let multipath daemon pick up new devices misc.execCmd([constants.EXT_MULTIPATH], sudo=True)