Is there a command or script that can tell me for how long the server has been up since installation?
(either by checking system installation date (+ removing shutdown-time) or by checking main disk uptime)
something similar to what "crystal disk info" can do for windows
Thanks
Between approximately this time:
Fri Jul 3 19:31:00 UTC 2020
and approximately this time:
Fri Jul 3 20:31:00 UTC 2020
I couldn't install any packages from us.archive.ubuntu.com,
but otherwise my connection was fine.
$ sudo apt install --reinstall k4dirstat
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 0 not upgraded.
Need to get 230 kB of archives.
After this operation, 0 B of additional disk space will be used.
Err:1 http://us.archive.ubuntu.com/ubuntu bionic/universe amd64 k4dirstat amd64 3.1.3-1
Cannot initiate the connection to us.archive.ubuntu.com:80 (2001:67c:1562::15). - connect (101: Network is unreachable) Cannot initiate the connection to us.archive.ubuntu.com:80 (2001:67c:1562::18). - connect (101: Network is unreachable)
E: Failed to fetch http://us.archive.ubuntu.com/ubuntu/pool/universe/k/k4dirstat/k4dirstat_3.1.3-1_amd64.deb Cannot initiate the connection to us.archive.ubuntu.com:80 (2001:67c:1562::15). - connect (101: Network is unreachable) Cannot initiate the connection to us.archive.ubuntu.com:80 (2001:67c:1562::18). - connect (101: Network is unreachable)
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?
That's over an hour of downtime, but there wasn't anything on the Canonical status page.
Jul 3, 2020
No incidents reported today
I can't replicate the problem anymore, but here is the output of several commands during the interruption:
$ ping -c 5 us.archive.ubuntu.com
connect: Network is unreachable
$ host -v us.archive.ubuntu.com
Trying "us.archive.ubuntu.com"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 6730
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;us.archive.ubuntu.com. IN A
Received 39 bytes from 127.0.0.53#53 in 0 ms
Trying "us.archive.ubuntu.com"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 7987
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;us.archive.ubuntu.com. IN AAAA
;; ANSWER SECTION:
us.archive.ubuntu.com. 60 IN AAAA 2001:67c:1562::15
us.archive.ubuntu.com. 60 IN AAAA 2001:67c:1562::18
Received 95 bytes from 127.0.0.53#53 in 25 ms
Trying "us.archive.ubuntu.com"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 31711
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;us.archive.ubuntu.com. IN MX
Received 39 bytes from 127.0.0.53#53 in 23 ms
$ dig us.archive.ubuntu.com
; <<>> DiG 9.11.3-1ubuntu1.12-Ubuntu <<>> us.archive.ubuntu.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 18603
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 65494
;; QUESTION SECTION:
;us.archive.ubuntu.com. IN A
;; Query time: 0 msec
;; SERVER: 127.0.0.53#53(127.0.0.53)
;; WHEN: Fri Jul 03 16:10:01 EDT 2020
;; MSG SIZE rcvd: 50
$ systemd-resolve us.archive.ubuntu.com
us.archive.ubuntu.com: resolve call failed: 'us.archive.ubuntu.com' does not have any RR of the requested type
$ nslookup us.archive.ubuntu.com
Server: 127.0.0.53
Address: 127.0.0.53#53
Non-authoritative answer:
Name: us.archive.ubuntu.com
Address: 2001:67c:1562::15
Name: us.archive.ubuntu.com
Address: 2001:67c:1562::18
$ wget --no-proxy --spider us.archive.ubuntu.com
Spider mode enabled. Check if remote file exists.
--2020-07-03 16:11:52-- http://us.archive.ubuntu.com/
Resolving us.archive.ubuntu.com (us.archive.ubuntu.com)... 2001:67c:1562::15, 2001:67c:1562::18
Connecting to us.archive.ubuntu.com (us.archive.ubuntu.com)|2001:67c:1562::15|:80... failed: Network is unreachable.
Connecting to us.archive.ubuntu.com (us.archive.ubuntu.com)|2001:67c:1562::18|:80... failed: Network is unreachable.
and after the interruption:
$ ping -c 5 us.archive.ubuntu.com
PING ubuntu.com (91.189.88.180) 56(84) bytes of data.
64 bytes from cactuar.canonical.com (91.189.88.180): icmp_seq=1 ttl=56 time=75.1 ms
64 bytes from cactuar.canonical.com (91.189.88.180): icmp_seq=2 ttl=56 time=129 ms
64 bytes from cactuar.canonical.com (91.189.88.180): icmp_seq=3 ttl=56 time=82.9 ms
64 bytes from cactuar.canonical.com (91.189.88.180): icmp_seq=4 ttl=56 time=76.4 ms
64 bytes from cactuar.canonical.com (91.189.88.180): icmp_seq=5 ttl=56 time=79.7 ms
--- ubuntu.com ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4003ms
rtt min/avg/max/mdev = 75.176/88.823/129.794/20.661 ms
$ host -v us.archive.ubuntu.com
Trying "us.archive.ubuntu.com"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20309
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;us.archive.ubuntu.com. IN A
;; ANSWER SECTION:
us.archive.ubuntu.com. 3 IN A 91.189.91.39
us.archive.ubuntu.com. 3 IN A 91.189.91.38
Received 71 bytes from 127.0.0.53#53 in 2 ms
Trying "us.archive.ubuntu.com"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 15398
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;us.archive.ubuntu.com. IN AAAA
;; ANSWER SECTION:
us.archive.ubuntu.com. 4 IN AAAA 2001:67c:1562::18
us.archive.ubuntu.com. 4 IN AAAA 2001:67c:1562::15
Received 95 bytes from 127.0.0.53#53 in 1 ms
Trying "us.archive.ubuntu.com"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 8865
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;us.archive.ubuntu.com. IN MX
Received 39 bytes from 127.0.0.53#53 in 86 ms
$ dig us.archive.ubuntu.com
; <<>> DiG 9.11.3-1ubuntu1.12-Ubuntu <<>> us.archive.ubuntu.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 37941
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 65494
;; QUESTION SECTION:
;us.archive.ubuntu.com. IN A
;; ANSWER SECTION:
us.archive.ubuntu.com. 17 IN A 91.189.91.39
us.archive.ubuntu.com. 17 IN A 91.189.91.38
;; Query time: 0 msec
;; SERVER: 127.0.0.53#53(127.0.0.53)
;; WHEN: Fri Jul 03 16:53:02 EDT 2020
;; MSG SIZE rcvd: 82
$ systemd-resolve us.archive.ubuntu.com
us.archive.ubuntu.com: 91.189.91.38
91.189.91.39
-- Information acquired via protocol DNS in 84.5ms.
-- Data is authenticated: no
$ nslookup us.archive.ubuntu.com
Server: 127.0.0.53
Address: 127.0.0.53#53
Non-authoritative answer:
Name: us.archive.ubuntu.com
Address: 91.189.91.39
Name: us.archive.ubuntu.com
Address: 91.189.91.38
Name: us.archive.ubuntu.com
Address: 2001:67c:1562::18
Name: us.archive.ubuntu.com
Address: 2001:67c:1562::15
$ wget --no-proxy --spider us.archive.ubuntu.com
Spider mode enabled. Check if remote file exists.
--2020-07-03 16:52:41-- http://us.archive.ubuntu.com/
Resolving us.archive.ubuntu.com (us.archive.ubuntu.com)... 91.189.91.39, 91.189.91.38, 2001:67c:1562::18, ...
Connecting to us.archive.ubuntu.com (us.archive.ubuntu.com)|91.189.91.39|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: unspecified [text/html]
Remote file exists and could contain further links,
but recursion is disabled -- not retrieving.
My questions:
Was this due to Ubuntu server downtime, some kind of transient DNS problem from my ISP, or something else entirely?
In case of future interruptions, how should I distinguish Ubuntu server downtime from a DNS problem?
Is there a place I can go to check the status of a subdomain like us.archive.ubuntu.com?
I wanted to to make some reports on uptime of some a using google sheet. I wanted to update google sheet every day with the reports. I wanted to make report of uptime of at least 100 computers running on linux.
Is there any easy way to calculate uptime excluding period system is suspended? I would like to count time I've spent in front of computer.
On a multi user system, I want to measure each user's CPU usage in seconds of cpu time. For the purpose of this measurement, I assume that if a PID belongs to a user, this user is causing the CPU time - that is I'm ignoring daemons and the kernel.
Currently I'm doing this, every five seconds:
ps auxx, the sum of utime, cutime, stime and cstime from /proc/[pid]/statt = x / interval (interval isn't always exactly 5 seconds when there's high load)If I run this, I get sensible looking values. For instance: A user on this system was spinning in python (while True: pass), and the system was showing round about 750 milliseconds of CPU time per second. When the system hung for a bit, it reported 1600ms for one 1-second inverval. Which seems about right, but I undestand that these values can be deceiptful, especially given I don't really understand them.
So my question is this:
What is a fair and correct way to measure CPU load on a per-user basis?
The method has to be rather accurate. There might be many hundreds of users on this system, so extracting percentages from ps aux will not be accurate enough, especially for short-lived threads which many pieces of software like to spawn.
While this might be complicated, I absolutely know it's possible. This was my starting point:
The kernel keeps track of a processes creation time as well as the CPU time that it consumes during its lifetime. Each clock tick, the kernel updates the amount of time in jiffies that the current process has spent in system and in user mode. — (from the Linux Documentation Project)
The value I'm after is the amount of seconds (or jiffies) that a user has spend on the CPU, not a percentage of system load or cpu usage.
It's important that we measure CPU time while the processes are still running. Some processes will only last for half a second, some will last for many months - and we need to catch both sorts, so that we can account for users' CPU time with fine granularity.