Interesting Tech Note for Linux – Testing the read speed of a hard disk


I look at IBM’s support feeds every day to see what interesting new info comes down the fire hose … this was a first one: Linux drive performance testing! I work with allot of Linux and AIX so this is interesting stuff, I just did not think I would see it in an IBM support feed.

****************************************************

Problem
How can I test to see if all drives are reading at the same speed?
Cause
One reason that hard disks fall out of RAID arrays is a difference in read/write speeds between the drives in the RAID array. You can use the hdparm utility to test each disk to determine whether all disks are reading at the same speed.
Resolving the problem
To run the tests follow the steps below:
Telnet into the server and log in as an administrative user.
Get a list of all hard disks on the system:

wd disk-info

Run the following command on each hard disk on the system:

hdparm -Tt /dev/Disk

Example: hdparm -Tt /dev/sda

The output will look similar to the following:

/dev/sda:
Timing cached reads: 14036 MB in 2.00 seconds = 7027.55 MB/sec
Timing buffered disk reads: 226 MB in 3.02 seconds = 74.79 MB/sec

For hard disks to work together in a RAID, the read speeds should be similar to each other. For best results you should run this test multiple times on each disk and average the results.

Problem
How can I test to see if all drives are reading at the same speed?
Cause
One reason that hard disks fall out of RAID arrays is a difference in read/write speeds between the drives in the RAID array. You can use the hdparm utility to test each disk to determine whether all disks are reading at the same speed.
Resolving the problem
To run the tests follow the steps below:
Telnet into the server and log in as an administrative user.
Get a list of all hard disks on the system:

wd disk-info

Run the following command on each hard disk on the system:

hdparm -Tt /dev/Disk

Example: hdparm -Tt /dev/sda

The output will look similar to the following:

/dev/sda:
Timing cached reads: 14036 MB in 2.00 seconds = 7027.55 MB/sec
Timing buffered disk reads: 226 MB in 3.02 seconds = 74.79 MB/sec

For hard disks to work together in a RAID, the read speeds should be similar to each other. For best results you should run this test multiple times on each disk and average the results.

 

Linux Security Alert: X.org Server Allows Anyone to Unlock Computer


https://www.linux.com/news/enterprise/biz-enterprise/538089-xorg-server-allows-anyone-to-unlock-computer

I had not heard of this one yet but I am going to my servers right now and checking for the latest security patches … if your servers do not run x.org server then you have nothing to fear. While you are at it, check your workstations too …..

Debmirror – Be independent on Linux


ToalSystems has finally decided that we have enough Linux servers to create out own mirror site – for multiple Linux releases. Over the last week we created a new Ubuntu mirror site on our internal network and will be adding a new CentOS mirror site as well. Currently we are still debating whether we want to register either or both sites for public use as the discussion is still going on whether we want to “adjust/change” the mirror site and add things of our own into it.  If we really decide to make the mirror site public I will blog it on this site.

 

Here is a short primer on how to set up a Ubuntu mirror site using DEBMIRROR – as opposed to RSYNCMIRROR which is a total copy/replica of the site you decide to pull from (including any back-version they have).

It is worth i if you want to have more control over what you offer your Linux  servers/workstations for updates and what versions you support. I also believe in having control where your machines go for an update … I dislike out internal machines going to outside sites to get updates if I can keep them inside. Also, having been burnt by the two big storms we had in the North East (Irene and Alfred) and which severely impacted our data center and the network connectivity, I like not having to be relicant on critical updated having to access the Internet but rather being able to pull all data down from an internal site.

 

 

Notes on Linux: Run a compact from the OS


I have been pretty busy as of late, hence my reduced blogging – but this is one I come across as a question quite frequently from people who are new to Notes/Domino on Linux.

On the Windows OS it is quite simple to run a compactor task from a command prompt or a batch file. However, when on Linux you will often be met by the following error message:

error while loading shared libraries: libnotes.so: cannot open shared object file: No such file or directory

This error message can appear on either a Linux desktop that has the Notes client installed or a server that has Domino installed. Basically the OS is complaining that it can’t find libnotes.so which usually resides in the /usr/lib folder on your machine. All you have to do is to create some links so that the Notes/Domino code can find this file. And, you will need to do the same for two other files as t the same time.

You will have to be root or have sudo rights to execute this:

sudo ln -s /opt/ibm/lotus/notes/libnotes.so /usr/lib/libnotes.so
sudo ln -s /opt/ibm/lotus/notes/libndgts.so /usr/lib/libndgts.so
sudo ln -s /opt/ibm/lotus/notes/libxmlproc.so /usr/lib/libxmlproc.so

You can see, I have my Notes client (Ubuntu 10.04) installed in [/opt/ibm/lotus/notes] which is the default location. If you have Notes installed someplace else, you will need to adjust the commands above accordingly.

the same commands will solve this issue for Domino server installations as well, though you will likely have Domino installed in [/opt/ibm/lotus/domino]  so just adjust the commands and off you go!

Accountment: Ubuntu 10.04 LTS is now an officially supported platform for Notes 8.5.2


I did just recently rant about IBM being behind on what versions of Linux they support for Notes Domino so this tech note comes timely. I would love to take credit for “pushing IBM along” but  – no matter what truths I twist, not even I can make that case … 😉

The great news is that all us Ubuntu lovers can install Notes on version 10.04 and receive support. Also supported are Red Hat 5.4 (or newer), SUSE Enterprise Desktop 10.0 SP3 or Version 11.0,  and Ubuntu 8.04.

 

IBM Lotus Notes 8.5.2 System Requirements – Linux

 

Linux – Lotus and fine Wine


Wine 1.3.4 adds ARM architecture support – The H Open Source: News and Features.

some of you might have read my post regarding how to get the Lotus Notes Admin and Developer client to run “natively” in Linux: what means without having to run a virtual Windows cleint. I use WINE for that purpose and it looks like the guys from Wine finally tool the version 1.3.4 out of the BETA stage and into production . . .

Guess what I am updating on my machine tonight??

PS: next to running my admin and developer client I hope the new 1.3.4 will make Civilization V run better on my machine … I have an empire to build after all!