On server startup xend start or a later
xend restart needs approx. 30 min to
start/restart. Without attached FC devices
xend start/restart needs only some
seconds.
server type: Fujitsu Primergy RX600-S5
The time gets lost in xen/xend/XendNode.py
line 329 while calling
vscsi_util.get_all_scsi_device().
329 for pscsi_record in
vscsi_util.get_all_scsi_devices():
330 scsi_id = pscsi_record['scsi_id']
331 if scsi_id:
332 saved_HBA_uuid = None
I think, in most cases we don't need all
the PSCSI devices registered in
xend, but only a few of it.
So a good solution for this perforamce
issue is to scan only the SCSI device
paths we need, controlled by a new option
in xend-config.sxp.
I have made a patch to allow specification
of scsi devices we need in xend
in the config file xend-config.sxp.
The new options pscsi-device-mask expects a
list of device ids oder partial
device ids like the option of lsscsi, e.g.
(pscsi-device-mask ('<partial-dev-id1'
'partial-dev-id2' ...))
Without this option set in xend-config.sxp
or if lsscsi is not support, all
device paths are process like today.
Signed-off-by: Lutz Dube
Lutz.Dube@xxxxxxxxxxxxxx
diff -r fac9d58d3c8a -r 02d55e7d0e94
tools/examples/xend-config.sxp
--- a/tools/examples/xend-config.sxp Wed
Jul 21 13:15:33 2010 +0200
+++ b/tools/examples/xend-config.sxp Fri
Jul 23 08:23:19 2010 +0200
@@ -294,3 +294,11 @@
# we have to realize this may incur
security issue and we can't make sure the
# device assignment could really work
properly even after we do this.
#(pci-passthrough-strict-check yes)
+
+# If we have a very big scsi device
configuration, start of xend is slow,
+# because xend scans all the device paths
to build its internal PSCSI device
+# list. If we need only a few devices for
assigning to a guest, we can reduce
+# the scan to this device. Set list list
of device paths in same syntax like in
+# command lsscsi, e.g. ('16:0:0:0' '15:0')
+# (pscsi-device-mask ('*'))
+
diff -r fac9d58d3c8a -r 02d55e7d0e94
tools/python/xen/util/vscsi_util.py
--- a/tools/python/xen/util/vscsi_util.py Wed
Jul 21 13:15:33 2010 +0200
+++ b/tools/python/xen/util/vscsi_util.py Fri
Jul 23 08:23:19 2010 +0200
@@ -148,11 +148,12 @@ def
_vscsi_get_scsidevices_by_sysfs():
return devices
-def vscsi_get_scsidevices():
+def vscsi_get_scsidevices(mask=""):
""" get all scsi
devices information """
- devices =
_vscsi_get_scsidevices_by_lsscsi("")
- if devices:
+ devices =
_vscsi_get_scsidevices_by_lsscsi("[%s]" % mask)
+ if devices or (len(mask) and mask[0]
!= "*"):
+ # devices found or partial device
scan
return devices
return
_vscsi_get_scsidevices_by_sysfs()
@@ -274,9 +275,9 @@ def
get_scsi_device(pHCTL):
return
_make_scsi_record(scsi_info)
return None
-def get_all_scsi_devices():
+def
get_all_scsi_devices(mask=""):
scsi_records = []
- for scsi_info in
vscsi_get_scsidevices():
+ for scsi_info in
vscsi_get_scsidevices(mask):
scsi_record =
_make_scsi_record(scsi_info)
scsi_records.append(scsi_record)
return scsi_records
diff -r fac9d58d3c8a -r 02d55e7d0e94
tools/python/xen/xend/XendNode.py
--- a/tools/python/xen/xend/XendNode.py Wed
Jul 21 13:15:33 2010 +0200
+++ b/tools/python/xen/xend/XendNode.py Fri
Jul 23 08:23:19 2010 +0200
@@ -326,7 +326,12 @@ class XendNode:
pscsi_table = {}
pscsi_HBA_table = {}
- for pscsi_record in
vscsi_util.get_all_scsi_devices():
+ pscsi_records = []
+ for pscsi_mask in
xendoptions().get_pscsi_device_mask():
+ pscsi_records +=
vscsi_util.get_all_scsi_devices(pscsi_mask)
+ log.debug("pscsi record
count: %s" % len(pscsi_records))
+
+ for pscsi_record in pscsi_records:
scsi_id =
pscsi_record['scsi_id']
if scsi_id:
saved_HBA_uuid = None
diff -r fac9d58d3c8a -r 02d55e7d0e94
tools/python/xen/xend/XendOptions.py
--- a/tools/python/xen/xend/XendOptions.py Wed
Jul 21 13:15:33 2010 +0200
+++ b/tools/python/xen/xend/XendOptions.py Fri
Jul 23 08:23:19 2010 +0200
@@ -164,6 +164,9 @@ class XendOptions:
"""
print >>sys.stderr,
"xend [ERROR]", fmt % args
+ """Default mask for
pscsi device scan."""
+ xend_pscsi_device_mask = ['*']
+
def configure(self):
self.set_config()
@@ -429,6 +432,10 @@ class XendOptions:
def
get_pci_dev_assign_strict_check(self):
return
self.get_config_bool("pci-passthrough-strict-check",
self.pci_dev_assign_strict_check_default)
+
+ def get_pscsi_device_mask(self):
+ return
self.get_config_value("pscsi-device-mask",
+
self.xend_pscsi_device_mask)
class XendOptionsFile(XendOptions):
