543 reputation
1622
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location Yokosuka, Japan
age 47
visits member for 5 years, 7 months
seen Nov 4 at 4:51

Englishman from Royal Leamington Spa who has lived continuously in Japan since 1988.


Oct
30
comment What determines the time to first ping response in an OS?
@joeqwerty in some managed services, the failure to respond to ping is escalated to the owner of the server. When a new VM is started up there will be a certain delay until Ping replies starts and these are logged as failures. Picky customers have asked "Why are we getting alerts?". I want to know exactly what services have to be up for Ping to be returned. e.g. Naïve administrators may assume erroneously that the network card will return pings as soon as it gets power, but that is obviously incorrect.
Oct
30
comment What determines the time to first ping response in an OS?
Obviously it is not the firewall that responds to ping nor is it the network card. If I am not mistaken, the card just places the Ethernet frames in a buffer for the operating system's TCP Stack/Driver to inspect and respond to. The firewall hooks into the TPC Stack to modify it's behaviour. i.e. to filter certain packets and/or to allow the TPC Stack to return or not return ICMP ECHO requests. I think you will find that the network card doesn't come into this discussion at all..
May
22
comment I have two servers, how can I find the files that are different?
Hey, guys don't downv ote this solution just because it is commercial product. I didn't specify a free solution.
Sep
5
comment What kind of issues would occur if resolve.conf had no dns servers set?
I'm trying to gather the information about specific problems that will occur in order to make a case to someone that this is not a good idea. The answers which mention SSH reverse lookups failing are a good example which the customer would encounter when they first logged into their un-configured box.
Sep
5
comment What kind of issues would occur if resolve.conf had no dns servers set?
It's a hosted server somewhat like an Amazon instance.
Sep
5
comment What kind of issues would occur if resolve.conf had no dns servers set?
He uses windows. I'm asking specifically about Linux...
Sep
5
comment What kind of issues would occur if resolve.conf had no dns servers set?
I would like this to be a turnkey system too, but I am gathering information of about what issues would occur in order to present a case to the decision maker that this may not be a good idea
Sep
5
comment What kind of issues would occur if resolve.conf had no dns servers set?
I would like this to be a turnkey system too, but I am gathering information of about what issues would occur in order to present a case to the decision maker that this may not be a good idea
Sep
5
comment What kind of issues would occur if resolve.conf had no dns servers set?
..this is what I meant by "obvious inability to resolve hosts". I was thinking of other side effects that would not be so apparent. e.g. if the ntp settings included the host name then the time would drift.
Sep
5
comment What kind of issues would occur if resolve.conf had no dns servers set?
I would like this to be a turnkey system too, but I am gathering information of about what issues would occur in order to present a case to the decision maker that this may not be a good idea.
Mar
8
comment Can the encryption option with zip on Linux when used from the command line?
N.b. The zip command on Redhat is copyright Info-ZIP.
Mar
8
comment Can the encryption option with zip on Linux when used from the command line?
@ChrisS I guess there is a free OpenSSL client for windows too. The zipped files will be sent to an FTP server to be picked up by a Windows user. The encryption is mainly just to avoid a casual user from accidentally peeking into the file.
Jan
26
comment What utilities do you use and how do you use them when benchmarking your harddrive subsystem for a SAN replacement?
Does IOMeter come with a command line version, the screenshots suggest it is a GUI application.
Jan
24
comment How would the outside world access my machine?
The key point is open a port on the Internet side of your router in the NAT settings area and redirect that to the 8125 port on your PC on the LAN side of the router. Your PC on the LAN side will have been assigned an IP other than the local host IP i.e. not 127.0.0.1 something like 10.*.*.* or 192.168.*.*. If you are using a LAN IP address assigned by the router, you might want to consider using a static IP address in case your PC's IP address changes.
Nov
4
comment Server performance and disk usage portal?
I had thought of Nagios, but I am looking for something self contained to the server. I'm not sure if that makes sense but it removes the need for a centralized monitoring server. Monitoring agents are installed on the servers but handled by another division. I'd like to be able to check the situation by myself.
Oct
1
comment Should you still spread a hard drive order over several vendors?
It's worth taking a look at Google's research on disk failures. They have a lot of disks and have collected the data and analysed it: labs.google.com/papers/disk_failures.pdf
Oct
1
comment 100% uptime for a web application
Some services which advertise 100% uptime offer a penalty clause in the small print like "2 days free for every day the service is down". So the 100% is for marketing with some money reserved for paybacks. No engineer would offer 100% uptime and some would find another job if they found their services had been advertised as such with the expectation of 100% uptime. Also, maintenance windows should be arranged beforehand as part of the SLA and when planned these don't count against the 100%.
Oct
3
comment Daily Activity Report On Linux
Actually gt5.sourceforge.net seems to report on disk space in a useful way.
Oct
3
comment Daily Activity Report On Linux
Yes, logwatch is what I had encountered before. Will it discover application logs?
Oct
3
comment Can ping websites but unable to view them
Successful pinging is testing if IP routing of ICMP packets and DNS resolutions are testing that UDP packets are being routed but Telnet and the browser are telling you that TCP traffic to port 80 is being blocked. This is most probably a firewall local to the server as you mention the laptop connected to the works fine. The failure to Telnet is telling you that even if you bypass any proxy by going straight to the port, TCP/IP is still blocked. Also check the ipconfig settings for the default gateway is what you expect.