Ugo's Blog

Here's a list of commands that you should execute and then share the output to someone who can help you figure out what resource is the bottleneck in your system. Note, it requires the  sysstat  and  procps  packages (ubuntu and RHEL and its derivatives): uptime vmstat 1 10 iostat -xN 2 10 mpstat -P ALL 3 10 pidstat 1 10 free -mw (or free -m, if your OS doesn't support -w)  uptime is to see the load averages on the system. vmstat is mostly used to tell if the system is swapping or not. If you see significant numbers in the 'si' and 'so' columns, your system is most likely swapping (using the hard drive as RAM), which usually slows performance a lot. iostat is mostly used to determine if your disk subsystem is not able to cope with the load. If you see one or more lines that shows 100 or close almost constantly, it is probably the case.  If it is your swap volume, you probably saw numbers in the 'si' and 'so' columns in the  vmsta...

Here's a list of commands that you should execute and then share the output to someone who can help you figure out what resource is the bottleneck in your system. Note, it requires the sysstat and  procps packages (ubuntu and RHEL and its derivatives): vmstat 1 10 iostat -xN 2 10 mpstat -P ALL 3 10 The first one is mostly used to tell if the system is swapping or not. If you see numbers in the 'si' and 'so' columns, your system is most likely swapping (using the hard drive as RAM), which usually slows performance a lot. The second one is mostly used to determine if your disk subsystem is not able to cope with the load. If you see one or more lines that shows 100 or close almost constantly, it is probably the case.  If it is your swap volume, you probably saw numbers in the 'si' and 'so' columns in the  vmstat  output. The third one shows the % of the CPU time used by different functions of the server. I'll explain the most used one...

After publishing my last post, I found out that many forks of kSar have been created. I didn't spend too much time comparing them, but ksar2  looks promising. Have fun!

Hi, I really like using kSar for troubleshooting on Linux, but it doesn't work out-of-the-box with version 7 of Red Hat Enterprise Linux or its derivatives (CentOS, Scientific Linux, etc.).  It just doesn't work with the standard " sar -a " command, so one of my colleague had a bit of free time and found the combination of arguments that makes it work. It looks like there is one of the options that are included in -a was not included in previous versions, and kSar cannot process the additional output. Here's the command line that works: sar -bBdqrRSuvwWyp -I SUM -I XALL -m ALL -n ALL -u ALL -P ALL The 'p' is, however, optional. I add it to have pretty names for disks instead of dev2-0, dev253, etc. On a side note, if you want to have better results, change the frequency at which the sar cronjob runs (in /etc/cron.d/sysstat , change the '*/10' by just '*'). Also, if you want to see 'waiting for I/O' data with RHEL 7, go in...

I find it hard to see what's using the RAM in a server and ps_mem can help.  It lets you know the memory usage of applications. I haven't found how to install it on Ubuntu, but on Red Hat and derivatives, it's available in the EPEL repo.  You can use it by simply executing the ps_mem command, which gives this kind of output: [root@vps1 ~]# ps_mem  Private  +   Shared  =  RAM used       Program   8.0 KiB +  24.0 KiB =  32.0 KiB       agetty (2)   4.0 KiB +  30.0 KiB =  34.0 KiB       xinetd   4.0 KiB +  49.5 KiB =  53.5 KiB       lvmetad   0.0 KiB +  73.5 KiB =  73.5 KiB       saslauthd (2)   8.0 KiB +  89.0 KiB =  97.0 KiB       pmdadm  16.0 KiB + 142.5 KiB = 158.5 KiB       systemd-udevd 128.0 KiB +  90.0 KiB =...

I discovered an utility a few weeks ago and I thought it would be worth sharing. This utility is especially useful when you are looking for files that take a lot of disk space on your system.  As an example, I received a Nagios notification saying that /var had less than 15% free.  I logged on the system to see what is taking too much space. In the past, I would have use the du command (du -hs /var/*, then du -hs /var/log/* and so on), but I used ncdu.  I cd'd into /var, then ran 'ncdu'. Here are screen shots of an example (different of what happened yesterday): This is what we see when we start ncdu in /var: We can use the arrows up and down to select a folder and use the left and right arrows to go up/down the tree. In this case, I simply used the right-hand side arrow a few times until I got to the folder that contains the most data: That's already great, but that's before digging into the help (using ?).  The options are (version 1.13): Sortin...

I wanted our users to be able to user their AD credentials for SVN access. I first thought about putting everything in AD, including two groups for each repo (one read, one write), but I ended up only using AD for authentication, leaving the permissions to a local file since there is only one SVN server. That is how the apache conf file looks like: <VirtualHost *:443>   ServerName servername.domain   ## Vhost docroot   DocumentRoot "/var/www/html"   ## Directories, there should at least be a declaration for /var/www/html   <Location "/repos">     Require valid-user     Require ldap-user     Dav svn     AuthType Basic     AuthName "Use your Windows Credentials"     AuthBasicProvider file ldap     AuthUserFile /etc/httpd/conf/auth-conf-svn     AuthLDAPURL "ldap://DC1/dc=example,dc=domain?sAMAccountName?sub?(objectClass=*)"     AuthLDAPBindDN "...

I always enable the EPEL (Extra Packages for Enterprise Linux)   yum repository on my Red Hat (and similar) systems. However, some of the EPEL packages that I use freqently have been recently orphaned, then retired as per EPEL's policy . I found a way to download them manually.  Of course they're not updated but for these packages, I don't mind.  One example is nmon.  I'll show you how to manually download nmon even though it's retired. You have two options. The first one is to go there: http://buildlogs.cdn.centos.org/c7-epel.a64/ (for RHEL7-x64). The second is: First go to this  URL . At the top, enter "nmon" in the search box, then press Enter. Search for the version you want.  In my case, it is the EL6 version, so I clicked on it, and it sent me to this  URL On that page, there are download links for the source RPM and all the different arch.  In my case, the arch is x86_64, so I just had to click on the  download link ....

Note; if you're using a Lollipop phone, look at the "Tap & Go" feature. One very nice feature of the BlackBerry smartphones were the ability to perform a "real" full backup of your phone.  This way, you can either reset to factory settings or change phone without losing a single bit of data.  Now that we're using Android phones at work, I had to find an alternative and of course, it would not have to require the phones to be rooted. I decided to try Helium (https://play.google.com/store/apps/details?id=com.koushikdutta.backup&hl=en) and it did a good job.  However, I haven't found a good tutorial on how to use the free version.  I don't mind spending 5$ for a great application, but I thought I'd try the free version first.  The local backups were quite easy to do, but since my goal was to transfer the data to another phone, it was getting quite complex.  You cannot use cloud-based storage for your backups with the free version and you...

I don't know why but despite all of my searches, I haven't been able to find a good tutorial on how to deploy KeePass with an enforced configuration (set parameters that users cannot change). First, deployment: You can deploy the .msi and the related files using GPO, for example. But there is an easier way: simply copy the KeePass folder that contains the .exe to a network share.  Make sure only admins (only admin accounts, not your regular account). have write access to this share, all other users read-only. To do that you can install KeePass on your computer temporarily an copy the folder that is in the Program Files folder. Second, configuration enforcement: execute the local version of KeePass that you installed for step one.  Set the parameters as you would like them, then close KeePass.  A configuration file will be created in C:\Users\$username\AppData\Roaming\KeePass\KeePass.config.xml.  You can create a copy of this file that you will name KeeP...

I recently decided to upgrade my home firewall ( pfSense on a PC Engines WRAP) by something more recent.  The new APU system from PC Engines looked quite good so I ordered one unit of the 4-gig model.  When I received it, I tried a few things with it but lacked time.  The next time I worked on it, it was dead.  I create an RMA, returned the unit, and got a working one about 3 weeks later.  My original plan was just to upgrade pfSense and run it on more recent hardware.  My WRAP was kind of slow in the WebGUI (not that bad, I don't edit the configuration every day) and I don't think it could do a good job for an OpenVPN setup.  I looked around and also found other options for small factor computers but I decided to go with the APU when I saw that its processor had virtualization extensions.  I thought that I could try running another system, side-by-side with the firewall, allowing me to have a server that would always be on (I currently run cac...

Trying to install Talend using the installer and got this error: (main.tcl:32009): Pango-WARNING **: failed to choose a font, expect ugly output. engine-type='PangoRenderFc', script='latin' Funny...

HP has released its latest Service Pack for Proliant,  the integrated firmware and software bundle which it will support for the next year. New stuff: Support for (at least some) Gen9 servers Support for new Proliant options Includes VMware driver support Support for RHEL7 http://h17007.www1.hp.com/us/en/enterprise/servers/products/service_pack/spp/index.aspx

Hi, If you're looking for a book about puppet reporting and monitoring, you should have a look at this one:  http://bit.ly/1qbSxKC

In Audacity Edit – preferences – import/export – When exporting tracks to an audio file – use custom mix (done once) Open source file (mp3 or flac) Select Project Rate (bottom left) → 8000 File, export First time only: Select “Other uncompressed files” Click on “Options…” Choose Header → WAV (Microsoft), Encoding → U-Law On the Advanced Mixing Options, select 1 channel and add the unmapped channel to Channel 1 by clicking on the unmapped channel (it will get red borders) and then click on Channel: 1. Click OK Click OK at the “Edit Metadata” window Right-click on the output file, properties, summary, Advanced, make sure that: Channels = 1 (mono) Sample rate = 8kHz Format = CCITT u-Law

This is a book that was released a couple of weeks ago.  You can find my name in the list of technical reviewers  Puppet Beginner's Guide .

I use Dokuwiki for almost all of my documentation needs. One downside of this system, compared to MS Word, for example, is that you can't simply create a screen capture, then paste it in your document. However, I learned a trick today: Put all your screen captures in a MS Word document Follow the trick here to extract all the images to a folder.  If fact, you simply save your doc in the "HTML (filtered)" format. Rename all your image files and upload them (one-shot) into dokuwiki using the media manager, in the namespace of the page you're creating Use the media manager interface to do a trial and error session to determine the code you need for your images, or the syntax help . Copy-paste, then edit the name of the image for each image in your document. Hope this helps!

I've been looking for a while for a way to be able to write accentuated characters in vim, while logged via SSH on a Linux system.  It wasn't really hard to do, it just took me a lot of time to find the recipe: In the putty session, in the menu "Window - Translation" put UTF-8, then save the session.  The next time you open it, you'll be able to use accentuated characters!

Part of my job is to open support tickets, issues, cases, etc. to get help with hardware or software problems.  The quality level varies.  Here is my satisfaction level depending on the vendor (alphabetical order, with the products I've created tickets for in parenthesis): BSD Perimeter (pfSense): Excellent.  Very knowledgeable and their support contract is an hourly rate, so they don't mind working for you and they'll help as much as they can.  Always provided suggestions or solutions up to now. APC (UPS): Well, when you discover that your UPS needs a replacement under warranty and they only promise that they will ship it tomorrow (it took about 5 days to reach our office), you don't really care about how good the support may be.  At least they do make good products. Dell/Compellent (Storage Array): Very good.  Good knowledge base, helpfull techs, quality products as well (meaning we don't need to call them except for firmware updates, for which they...

I was looking for a way to reduce my VoIP bills.  I only use my VoIP lines to make long-distance calls and my provider forced me to spend at least 50$/year, which I never really used.  Someone recommended me voip.ms and I did the move.  I almost did the move for my home phone but when I called my home phone provider, they agreed on giving me a 15$/month rebate if I'd stick with them. voip.ms is very good because: Their prices are really good They offer a broad range of products For the price of a VoIP line, you get all the functions of a whole PBX Voicemail Ring Groups IVR DISA Multiple phones on the same account Callback Etc. Up to now, 100% reliable.