[linux-lvm] [PATCH 12/35] fsadm: Try to avoid calling LVM in the loops
Lukas Czerner
lczerner at redhat.com
Wed Sep 21 16:45:31 UTC 2011
We should try to avoid calling LVM in the loops since it will cause
significant slowdown when the loop has many iteration (there is a lot of
devices/lvs/vgs). Instead use temporary files to store the listing
before the loop and the just grep for it.
Signed-off-by: Lukas Czerner <lczerner at redhat.com>
---
scripts/fsadm.sh | 22 +++++++++++-----------
1 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/scripts/fsadm.sh b/scripts/fsadm.sh
index 4a4f625..517d10d 100755
--- a/scripts/fsadm.sh
+++ b/scripts/fsadm.sh
@@ -468,11 +468,13 @@ detect_device_group() {
ret=0
prev_vgname=""
vgs=""
+ tmp=$(mktemp)
+ LANG=C $LVM vgs -o vg_name,pv_name --separator ' ' --noheadings --nosuffix 2> /dev/null | sed -e 's/^ *//' | sort | uniq > $tmp
NOT_IN_GROUP=
IN_GROUP=
for i in $devices; do
- cur_vgname=$(LANG=C $LVM pvs -o vg_name --separator ' ' --noheadings --nosuffix --units k $i 2> /dev/null | sed -e 's/^ *//')
+ cur_vgname=$($GREP -e "$i$" $tmp | cut -d' ' -f1)
if [ -z $cur_vgname ]; then
NOT_IN_GROUP+="$i "
@@ -492,6 +494,7 @@ detect_device_group() {
vgs+=" $cur_vgname"
fi
done
+ rm -f $tmp
GROUP=$vgs
return $ret
}
@@ -540,7 +543,7 @@ create() {
# Devices are not in any group so we should find some.
# Either create a new one, or use the existing one, if
# there is only one vgroup, or use the one with enough
- # in it
+ # free space in it
if [ -z "$vgname" ]; then
vgroups=$($LVM vgs -o vg_name,vg_free --separator ' ' --noheadings --units b 2> /dev/null)
lines=$($LVM vgs -o vg_name,vg_free --separator ' ' --noheadings --units b 2> /dev/null | wc -l)
@@ -602,14 +605,17 @@ create() {
if [ "$name" ]; then
lvname="--name $name"
else
+ tmp=$(mktemp)
+ $LVM lvs $vgname --separator ' ' --noheadings > $tmp
for i in $(seq -w $MAX_VGS); do
- $LVM lvs $vgname --separator ' ' --noheadings | grep -e " lvol${i} " &> /dev/null
+ $GREP -e " lvol${i} " $tmp &> /dev/null
if [ $? -ne 0 ]; then
name="lvol${i}"
lvname="--name $name"
break;
fi
done
+ rm -f $tmp
fi
echo "going to create logical volume $lvname"
@@ -617,7 +623,7 @@ create() {
if [ $vg_create -eq 1 ]; then
dry $LVM vgcreate $VERB $vgname $devices
- elif [ ! -z $NOT_IN_GROUP ]; then
+ elif [ ! -z "$NOT_IN_GROUP" ]; then
dry $LVM vgextend $VERB $vgname $NOT_IN_GROUP
fi
@@ -1097,13 +1103,7 @@ add() {
rm -f $tmp
error "Please, specify group you want to add the device into"
elif [ $lines -eq 0 ]; then
- for i in $(seq -w $MAX_VGS); do
- $LVM vgs vg${i} &> /dev/null
- if [ $? -ne 0 ]; then
- vgname="vg${i}"
- break;
- fi
- done
+ vgname="vg001"
vg_create=1
fi
else
--
1.7.4.4
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