- Yu-Jung Cheng·Last edited by Yu-Jung Cheng on Mar 29, 2022Linked with GitHubContributed by
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tags: linux ntp chrony
setup chrony NTP server
apt update
apt install -y chrony
systemctl start chrony
systemctl enable chrony
root@ceph-mon-01:~# chronyc activity
200 OK
8 sources online
0 sources offline
0 sources doing burst (return to online)
0 sources doing burst (return to offline)
0 sources with unknown address
edit config with nearest zone
vim /etc/chrony/chrony.conf
#pool ntp.ubuntu.com iburst maxsources 4
#pool 0.ubuntu.pool.ntp.org iburst maxsources 1
#pool 1.ubuntu.pool.ntp.org iburst maxsources 1
#pool 2.ubuntu.pool.ntp.org iburst maxsources 2
pool 0.oceania.pool.ntp.org iburst maxsources 2
pool 1.oceania.pool.ntp.org iburst maxsources 2
pool 2.oceania.pool.ntp.org iburst maxsources 2
pool 3.oceania.pool.ntp.org iburst maxsources 2
allow all client on the same local network change to your own IP/networks
vim /etc/chrony/chrony.conf
allow 192.168.1.0/24
systemctl restart chrony
systemctl status chrony
setup NTP client with chrony
apt update
apt install -y chrony
# Change default ntp pool to the Chrony NTP server
vim /etc/chrony/chrony.conf
#pool ntp.ubuntu.com iburst maxsources 4
#pool 0.ubuntu.pool.ntp.org iburst maxsources 1
#pool 1.ubuntu.pool.ntp.org iburst maxsources 1
#pool 2.ubuntu.pool.ntp.org iburst maxsources 2
server 192.168.1.1 prefer iburst
systemctl restart chrony
check NTP server used by chronyd service
15 November 2020
logical volume manager (lvm)
PV - physical volume
VG - volume group
PE - physical extent
LV - logical volume
root@develop:/home/ycheng# lvmdiskscan
/dev/vda2 [ <20.00 GiB]
/dev/vdb [ 20.00 GiB]
/dev/vdc [ 20.00 GiB]
2 disks
1 partition
0 LVM physical volume whole disks
0 LVM physical volumes
# create PV
----------------------------------------------------------------
root@develop:/home/ycheng# pvcreate /dev/vdb
Physical volume "/dev/vdb" successfully created.
root@develop:/home/ycheng# pvcreate /dev/vdc
Physical volume "/dev/vdc" successfully created.
root@develop:/home/ycheng# lvmdiskscan
/dev/vda2 [ <20.00 GiB]
/dev/vdb [ 20.00 GiB] LVM physical volume
/dev/vdc [ 20.00 GiB] LVM physical volume
0 disks
1 partition
2 LVM physical volume whole disks
0 LVM physical volumes
root@develop:/home/ycheng# pvdisplay
"/dev/vdc" is a new physical volume of "20.00 GiB"
--- NEW Physical volume ---
PV Name /dev/vdc
VG Name
PV Size 20.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID LraVsw-U2HV-e2nA-z7rc-qKtx-QVmr-YNk0dF
"/dev/vdb" is a new physical volume of "20.00 GiB"
--- NEW Physical volume ---
PV Name /dev/vdb
VG Name
PV Size 20.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID o4dT1U-SkDI-lunc-2Q7n-60OJ-40TL-72zoFB
!!! remove PV
pvremove < PV Name >
# create VG
----------------------------------------------------------------
root@develop:/home/ycheng# vgcreate vg1 /dev/vdb /dev/vdc
Volume group "vg1" successfully created
root@develop:/home/ycheng# vgdisplay
--- Volume group ---
VG Name vg1
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 1
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 2
Act PV 2
VG Size 39.99 GiB
PE Size 4.00 MiB
Total PE 10238
Alloc PE / Size 0 / 0
Free PE / Size 10238 / 39.99 GiB
VG UUID OwIsAL-iQSB-FJb0-dGUG-O4ro-1iNK-sw7Baf
!!! create VG with PE size to 128MiB
vgcreate -s 128 vg1 /dev/vdb /dev/vdc
!!! remove VG
vgremove vg1
!!! maximum 65534 PEs.
# create LV
----------------------------------------------------------------
root@develop:/home/ycheng# lvcreate -L 8G -n lv1 vg1
Logical volume "lv1" created.
root@develop:/home/ycheng# lvcreate -l 100%FREE -n lv2 vg1
Logical volume "lv2" created.
root@develop:/home/ycheng# lvdisplay
--- Logical volume ---
LV Path /dev/vg1/lv1
LV Name lv1
VG Name vg1
LV UUID 03jsBD-3XKC-88oZ-XHwJ-uJHw-J92j-MtTGdL
LV Write Access read/write
LV Creation host, time develop, 2020-11-15 05:46:58 +0000
LV Status available
# open 0
LV Size 8.00 GiB
Current LE 2048
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
--- Logical volume ---
LV Path /dev/vg1/lv2
LV Name lv2
VG Name vg1
LV UUID zMhcOs-Xpib-SSyA-fmeI-6puj-k3v8-NXAsb6
LV Write Access read/write
LV Creation host, time develop, 2020-11-15 05:47:59 +0000
LV Status available
# open 0
LV Size 31.99 GiB
Current LE 8190
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1
!!! create "striped" allocation type LV 8GB
root@develop:/home/ycheng# lvcreate --type striped -i 2 -L 8G -n striped_lv1 vg1
Using default stripesize 64.00 KiB.
Logical volume "striped_lv1" created.
!!! allocate 100% free extends to create new LV. "-l < extends number >"
root@develop:/home/ycheng# lvcreate --type striped -i 2 -l 100%FREE -n striped_lv2 vg1
Using default stripesize 64.00 KiB.
Logical volume "striped_lv2" created.
!!! remove LV
lvremove /dev/vg1/striped_lv2
Create snapshot and merge (recovery)
----------------------------------------------------------------
root@develop:/home/ycheng# lvcreate -s -L 8G -n snap_striped_lv1 vg1/striped_lv1
Using default stripesize 64.00 KiB.
Logical volume "snap_striped_lv1" created.
root@develop:/home/ycheng# lvconvert --merge vg1/snap_striped_lv1
Merging of volume vg1/snap_striped_lv1 started.
vg1/striped_lv1: Merged: 100.00%
!!! remove snapshot
lvremove
Resize LV
----------------------------------------------------------------
root@develop:/home/ycheng# lvscan
ACTIVE '/dev/vg1/striped_lv1' [8.00 GiB] inherit
root@develop:/home/ycheng# lvresize -L +4G vg1/striped_lv1
Using stripesize of last segment 64.00 KiB
Size of logical volume vg1/striped_lv1 changed from 8.00 GiB (2048 extents) to 12.00 GiB (3072 extents).
Logical volume vg1/striped_lv1 successfully resized.
Remove PV from VG
----------------------------------------------------------------
pvmove /dev/vdc
vgreduce vg1 /dev/vdc
pvremove /dev/vdc
Rename VG
----------------------------------------------------------------
root@develop:/home/ycheng# vgscan
Reading volume groups from cache.
Found volume group "vg1" using metadata type lvm2
root@develop:/home/ycheng# vgrename vg1 new_vg1
Volume group "vg1" successfully renamed to "new_vg1"
root@develop:/home/ycheng# vgscan
Reading volume groups from cache.
Found volume group "new_vg1" using metadata type lvm2
Other commands
----------------------------------------------------------------
vgextend - add new PV to VG
vgchange - change VG attributes
lvextend - increase LV size
lvreduce - reduce LV size
Posted by Knowledge Base 2.0 at 17:29:00 No comments:
Chrony install and configure
[ Setup Chrony NTP server ]
# install and start chrony service
apt update
apt install -y chrony
systemctl start chrony
systemctl enable chrony
root@ceph-mon-01:~# chronyc activity
200 OK
8 sources online
0 sources offline
0 sources doing burst (return to online)
0 sources doing burst (return to offline)
0 sources with unknown address
# edit config with nearest zone.
vim /etc/chrony/chrony.conf
#pool ntp.ubuntu.com iburst maxsources 4
#pool 0.ubuntu.pool.ntp.org iburst maxsources 1
#pool 1.ubuntu.pool.ntp.org iburst maxsources 1
#pool 2.ubuntu.pool.ntp.org iburst maxsources 2
pool 0.oceania.pool.ntp.org iburst maxsources 2
pool 1.oceania.pool.ntp.org iburst maxsources 2
pool 2.oceania.pool.ntp.org iburst maxsources 2
pool 3.oceania.pool.ntp.org iburst maxsources 2
# allow all client on the same local network
# change to your own IP/networks
vim /etc/chrony/chrony.conf
allow 192.168.1.0/24
systemctl restart chrony
systemctl status chrony
[ Setup NTP client wiht Chrony ]
apt update
apt install -y chrony
# Change default ntp pool to the Chrony NTP server
vim /etc/chrony/chrony.conf
#pool ntp.ubuntu.com iburst maxsources 4
#pool 0.ubuntu.pool.ntp.org iburst maxsources 1
#pool 1.ubuntu.pool.ntp.org iburst maxsources 1
#pool 2.ubuntu.pool.ntp.org iburst maxsources 2
server 192.168.1.1 prefer iburst
systemctl restart chrony
[ Check NTP server used by chronyd service ]
# check on both server or client.
root@ceph-mon-01:~# chronyc sources
210 Number of sources = 8
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
^- time.cloudflare.com 3 6 377 47 +680us[ +680us] +/- 7331us
^- ns1.att.wlg.telesmart.co> 2 6 377 49 -2532us[-2532us] +/- 33ms
^- ns1.tdc.akl.telesmart.co> 2 6 377 47 +2926us[+2926us] +/- 20ms
^- ntp2.ds.network 4 6 377 46 +443us[ +443us] +/- 30ms
^* ntp.seby.io 2 6 377 51 -148us[ -198us] +/- 1896us
^- ns2.tdc.akl.telesmart.co> 2 6 377 46 -3574us[-3574us] +/- 23ms
^- ntp03.lagoon.nc 2 6 377 48 -498us[ -498us] +/- 75ms
^- warrane.connect.com.au 3 6 377 47 +750us[ +750us] +/- 129ms
root@ceph-osd-02:/home/ycheng# chronyc sources
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
^* 192.168.1.1 3 6 17 19 -7870ns[ -13us] +/- 1959us
root@ceph-osd-02:/home/ycheng# chronyc sources -v
210 Number of sources = 1
.-- Source mode '^' = server, '=' = peer, '#' = local clock.
/ .- Source state '*' = current synced, '+' = combined , '-' = not combined,
| / '?' = unreachable, 'x' = time may be in error, '~' = time too variable.
|| .- xxxx [ yyyy ] +/- zzzz
|| Reachability register (octal) -. | xxxx = adjusted offset,
|| Log2(Polling interval) --. | | yyyy = measured offset,
|| \ | | zzzz = estimated error.
|| | | \
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
^* 192.168.1.1 3 6 17 44 -7870ns[ -13us] +/- 1959us
root@ceph-mon-01:~# chronyc clients
Hostname NTP Drop Int IntL Last Cmd Drop Int Last
===============================================================================
ceph-osd-02 6 0 5 - 62 0 0 - -
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