Graviton's questions

I have a VPS with the OS centos 5.7, and it is behaving very weirdly. My VPS is located on a 2-core machine.

For a 2-core machine, the load average I can see is very high, as evident when I use the top command to investigate:

 - 04:04:40 up 1 day, 22:43,  1 user,  load average: 6.23, 5.19, 4.72
Tasks:  59 total,   1 running,  58 sleeping,   0 stopped,   0 zombie
Cpu(s):  5.4%us,  3.4%sy,  0.0%ni, 85.4%id,  5.8%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:   1376256k total,   755908k used,   620348k free,        0k buffers
Swap:        0k total,        0k used,        0k free,        0k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
    1 root      15   0  2172  664  572 S  0.0  0.0   0:02.59 init
 1135 root      18  -4  2276  556  344 S  0.0  0.0   0:00.00 udevd
 1231 root      19   0 32716  564  460 S  0.0  0.0   0:00.00 brcm_iscsiuio
 1542 root      16   0  1828  580  488 S  0.0  0.0   0:03.24 syslogd
 1599 named     23   0 50596 3984 2024 S  0.0  0.3   0:01.26 named
 1615 root      18   0  7228 1044  644 S  0.0  0.1   0:00.00 sshd
 1626 root      15   0  2848  844  676 S  0.0  0.1   0:00.00 xinetd
 1638 root      18   0  3728 1316 1144 S  0.0  0.1   0:00.00 mysqld_safe
 1662 mysql     15   0  252m  99m 4876 S  0.0  7.4   9:21.01 mysqld
 1738 postgres  15   0 20348 3412 2900 S  0.0  0.2   0:00.26 postmaster
 1740 postgres  15   0 10128  904  388 S  0.0  0.1   0:01.42 postmaster
 1742 postgres  15   0 20348  984  468 S  0.0  0.1   0:05.20 postmaster
 1743 postgres  18   0 11128  812  292 S  0.0  0.1   0:00.13 postmaster
 1744 postgres  15   0 10308 1060  440 S  0.0  0.1   0:00.00 postmaster
 1757 mailnull  15   0  9524 2328 1836 S  0.0  0.2   0:00.99 exim
 1786 root      18   0  2172  720  552 S  0.0  0.1   0:02.58 dovecot
 1787 root      18   0  2648 1040  832 S  0.0  0.1   0:02.04 dovecot-auth

As you can see, the load is 6 ( for a 2-core machine), but when all the top processes added together, the memory and CPU consumption is minimum!

I thought this was an IO wait issue, so I used iostat -cx 30 to check:

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           5.43    0.02    3.36    5.80    0.00   85.39

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           3.79    0.00    0.33    2.09    0.00   93.79

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           3.61    0.00    0.30    5.67    0.00   90.42

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           1.91    0.00    0.22    1.04    0.00   96.83


avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           3.47    0.00    0.28    0.75    0.00   95.49


avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           3.93    0.00    0.44    2.62    0.00   93.01

As you can see, the %iowait is only 5%, it means that my processes only use 5% of the time waiting for IO operation, so it shows that the disk is not busy, there is no possibility that the high load average is caused by the processes are waiting for the disk, right?

Finally, to further confirm my point, I type in vmstat:

procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
 1  0      0 751928      0      0    0    0   120    99    0  105  5  3 85  6  0

As you can see, the process running is minimum, the b column is 0, indicating that the number of processes on UNINTERRUPTIBLE_SLEEP is 0. Further more, the bi column (blocks read from a block device) is only 120, not so high right? The si column (memory read from swap/disk) is 0. Finally, under the cpu header, the wa column shows that the CPU spends only 6% of time waiting for IO to complete.

All these rule out the possibility of IO operation as the bottleneck.

So, the conclusion is, the load average is very high and it degrades the performance of my website, however, this high load average is not caused by any of the following:

1. High CPU or memory usage by my processes
2. IO operation.

What can cause the high load average?

I have a VPS with a hosting provider. Recently, I discover that my load average is just extremely high. I have a 2 core VPS, and the load average can go up to 9 or 10, as shown below!

I initially thought that this was because my CPU/RAM not enough, however, the VPS provider told me that it could be that my IO load is very heavy ( or other VPS on the same dedicated machine's IO load) is heavy.

I have no way to verify the claim.

Anyway I can check the usage of IO? And can I know whether the high IO usage is due to my VPS, or other VPS cohabitat on the same physical machine?

I am thinking about getting a VPS node from a hosting provider. But I am very unclear as to how the VPS node really works.

1. Assuming that the hosting provider promises Dedicated CPU of 2Ghz, 2 CPU Cores, Dedicated RAM 1000MB, does it follow that I will always get it, assuming that the hosting provider is not cheating me?
2. The VPS node can be a virtual machine, am I right?
3. In the event that it is a VM, and it cohabitats with a lot of other VMs on a server, will the usages of other VMs affect mine's performance?
4. Let's say in order to earn money, the hosting provider put too many VMs on a server, resulting in oversubscription ( assuming that for a server, the normal number of VMs can be put on it is 10, but the hosting provider puts 30), will that seriously impact my VM's performance?
5. How to ensure that the hosting provider won't oversubscribe?

I have subscribed to a VPS offered by a hosting provider. The guaranteed performance 1GB RAM, 1M bandwidth.

But I found that from time to time the websites can be very slow, so slow that it could take more than 30 seconds to load a simple Joomla website. However the website resumed the usual speed after a few minutes.

This created a problem for me as when I wanted to report the performance problem to the hosting provider. They would say to me "see, no problem". Of course there was no problem because the problem was only there for a few minutes , and everything was normal after that.

This ocassionally-slow problem would bug me a few days later and the cycle repeats.

I'm pretty sure that this is not the webapp problem because all the websites on the same VPS suffer the same problem at the same time. And the slowness only affect during a certain ( very brief) period of time. After that everything is normal. The normality will last a few days when brief slowness attacked again, and the cycle repeats.

Any idea how to solve this problem? Or is, there any service that I can use to record the time-series of the response time?

Is there anyway, on Windows machine, to automatically restart a certain windows service?

I have a simple batch file (forbat.bat), with the following content:

FOR /F "tokens=4 delims=," %%G IN ("deposit,$4500,123.4,12-AUG-09") DO @echo Date paid %%G

When I run this batch file, I can get the result.

Now, I want to break the lines into a few lines, to make them easier to read. This is what I did:

FOR /F "tokens=4 delims=," %%G IN ("deposit,$4500,123.4,12-AUG-09") 
 DO 
 @echo Date paid %%G 

This time, I got a "The syntax of the command is incorrect" error.

It seems that I must have missed some semicolons and slashes when introducing the line breaks. How to make the above code work in windows batch file?

I have a bat file on windows that execute a procdump operation. The issue with the batch file is that I need to cd to the batch file directory first before executing the job, or else the script won't work.

How to change to the current batch file directory?

I tried the following code in my procdump.bat:

cd "%~dp"
procdump -h devenv.exe mydump.txt

But it failed, the error message is:

The following usage of the path operator in batch-parameter substitution is invalid: %~dp"

For valid formats type CALL /? or FOR /?

Edit: The answer provided is working, but there is only one catch: if my current directory is different than the batch file directory, then I would get a "The system cannot find the path specified". Anyone has any ideas?

My ASP.NET MVC application on my development box is running wild; I can't even connected to localhost. In order to know what is the problem, I want to find the log file and examine it.

Where is the location of the ASP.NET Server log file? I couldn't find it in event viewer, so I don't know where else to look

In Windows System, there is this file at C:\WINDOWS\system32\drivers\etc\hosts. This file allows us to default a specific IP address to a host name.

The issue now is whether I can set multiple IP addresses to a host name. For example, can I do something like this:

192.168.244.128   gateway.net
192.168.226.129   gateway.net

And expect that the browser can resolve to both of them, see which one will work and thus point at that one?

If not, is there any other way to get the behavior I want?

Note: I am deploying this app in my own local area network, so there is no need for internet.

I have a few websites, hosted on other people's server. To ease my system admin maintenance task I am thinking about using scripts or software tool to do the backup automatically ( I don't want to manually click on a batch script or configure this and that every time whenever I have to do backup).

Is there any tools you can recommend?

I have a software, PingPlotter that allows me to identify the latency, round trip time, packet loss and a lot of other network statistics. I want to use those statistics as a proof that my ISP is providing a lousy connection in my area.

How to convince the ISP that the fault lies on their side, not on my side?

P/S: Even though we don't have SLA, but I still want them to admit that they are lousy.

I have a MS SQL server 2005 database on my database server. Recently the database server crashed, so I need to move the database to a new server. Is there anyway to restore teh mdf file from a crashed hard disk, assuming that the file wasn't located on bad sectors?

How to download the whole website in general and *.blogspot.com in particular? Note that I don't necessary have admin access to that website. In fact I am just trying to download a third party website just in case it goes into flames...

I have just installed SharePoint 2007 ( no config yet), and would like to get it work on Microsoft Office document collaboration.

Basically I want to be able to use SharePoint as the central repository for Microsoft Word, excel etc. So I need to configure my sharepoint app so that it can check in/ checkout all these documents.

Any ideas or pointers on how to do this?

I have written a PHP web application, and that app will have a .Net 3.5 Windows Service to run on back-end ( There is a reason for doing this). My application will have to transfer a large amount of images ( both in terms of quantity and file size) between the servers and the clients. So speed is definitely a consideration.

So for this kind of setup, should we self-host? Or should we rent a hosting? Which one is better in terms of cost, and support etc? If we were to rent a hosting, is there any company's service that we can use on?

Edit: Seems that rented hosting is the way to go; so is there any suggestion for this?

What is the command that can be used to get the IP address and the names of the computers that are located in the same network?

I am running Windows

Can Virtual machine detect the connection of a scanner? Or more generally, can virtual machine detect any hardware connection, including sound speaker, microphone and so on?

The point of me asking this is because I want to shift all my development, and my desktops into a virtual machines for easy backup and maintenance purpose. So I will be doing my scanning inside a VM, gmail chatting inside the VM, listening to songs inside the VM, synchronizing my mobile device inside the VM and so on.

Any thoughts?

Edit: I am using VMWare

I remote desktop into a remote computer, and want to restart it from inside. When that remote computer comes back to life, can I still log into it? I will lose the previous session, for sure, but can I still log into it?

My Windows XP is getting a bit slow in terms of bootup speed nowadays. Also, when I first click on My Computer item, it takes a while to get it out.

I am thus thinking about the tricks to speed up the booting.

A quick google search can turn up a lot of results, and a lot of tricks. One of the tricks is to use msconfig to reduce the startup item. But I have done that, and filtering out unwanted program. Still I think it's slow.

The question now is, is there a tool that tells me exactly what is slowing down my computers, and how to optimize the speed?

I want to delete MyNewService, but when I type in

sc delete MyNewService

I simply can't delete it because there is no such servic, due to

"the Specified service does not exist as an installed service"

error

Any ideas how to solve this problem?

Edit: as far as the service panel is concerned, the MyNewService is there all the time. I restarted the PC a few times and it's there.