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Showing posts from 2010

RHEL6 comes prepared for vSphere

A fresh install of RHEL6 contains several vSphere-ready components:
the standard kernel package contains kernel modules for the optimized VMware virtual hardware (network, storage, and memory balloon driver).
vmxnet3vmw_pvscsivmware_balloonand just like in earlier RHEL releases, there's drivers for the VMware graphics card and the mouse driver:
xorg-x11-drv-vmwarexorg-x11-drv-vmmouseEspecially the built-in network and storage drivers will make life easier for RHEL admins in vSphere environments.
That's great news ofcourse, but I'd like to stress that this is not equivalent to a full VMware Tools install, which would include extras such as shutdown/reboot/freeze/resume scripts, IP address display in the vSphere client, etc.

Enterprise Linux and state-of-the-art hardware: a difficult marriage

A customer bought a Dell Precision T7500 recently. Beautiful machine, awesome power, running CentOS5. The videocard in the machine was the first I ever saw with nothing but DisplayPort connectors: no old-style VGA, no DVI, no HDMI. At first, a 1680x1050 screen was connected using a DisplayPort-to-DVI connector, and that worked flawlessly.
But in came a new beast: a 30-inch 2560x1600 screen. The standard DVI cable can't handle this resolution, and neither can the DisplayPort-to-DVI connector, so even a dual-link DVI cable doesn't solve this issue. And I'm sure you'll agree: running such a beauty at 1920x1200 seems a waste.
I tried connecting the monitor directly using a DisplayPort cable, which can easily handle the maximum resolution, but the EL5/CentOS5 xorg-x11-drv-ati driver is too old: version 6.6.3 (with some backports from 6.12.2) doesn't detect DisplayPort-connected monitors correctly. Compiling a newer driver isn't easy, because the newer ones require Xor…

Which ESX version am I running on ?

(An update of an older post: now with vSphere 4.1 info. Further updated in 2011 with vSphere 5 info.)
Your Linux runs on a VMware VM, but which ESX version is it ? You can see for yourself (as already explained in an earlier post on this blog). Run "dmidecode" and look at lines 10, 11 and 12. The list has been updated with current info:
ESX 2.5 - BIOS Release Date: 04/21/2004 - Address 0xE8480 - Size 97152 bytes
ESX 3.0 - BIOS Release Date: 04/17/2006 - Address 0xE7C70 - Size 99216 bytes
ESX 3.5 - BIOS Release Date: 01/30/2008 - Address 0xE7910 - Size 100080 bytes
ESX 4 - BIOS Release Date: 08/15/2008 - Address 0xEA6C0 - Size 88384 bytes
ESX 4U1 - BIOS Release Date: 09/22/2009 - Address 0xEA550 - Size 88752 bytes
ESX 4.1 - BIOS Release Date: 10/13/2009 - Address 0xEA2E0 - Size 89376 bytes
ESX 5 - BIOS Release Date: 01/07/2011 - Address 0xE72C0 - Size 101696 bytes

USB-over-IP goes mainstream

I've been into virtualization for a long, long time, so I was familiar with the USB-over-IP concept. It has always been the preferred way to bring USB into a virtual machine, because it doesn't limit the flexibility of virtualization: live migration (vMotion), failover (HA), fault tolerance, ... can all handle USB-over-IP.
But I was still surprised to find a cheap USB-over-IP device in a local computer store: the Belkin Network USB Hub, NUH for short. 100 USD list price, became EUR 90 retail price here in Belgium. Not the greatest deal around, but no reason to feel grumpy.
Now let's see what this baby can do: the test setup consists of the Belkin NUH and two clients: a Windows Vista 32-bit laptop connected over WiFI and a Windows 2008 R2 64-bit VM on VMware vSphere connected over wired GigE. Then I gathered a diverse set of USB devices: USB memory sticks, USB hard drives, a USB smartcard reader, and a USB CD/DVD writer.
The NUH gets a DHCP address by default (can be changed t…

ESX home lab upgrade

My original home lab, three years old now, included two PC's running virtualization software, with Intel core 2 quad CPU's and 8 GB RAM each. While browsing for a replacement, I found Didier's Shuttle SX58J3 review. I researched some alternatives, but decided to go for the SX58J3 as well, fitted with 12 GB RAM and i7-970 CPUs, hexacores with hyperthreading.
shallow: depth is critical in my telco rack.reduced height: I might get 4 shuttles in the same space as 2 minitowers earlier. They're actually slightly wider, but not by much.
12 GB per server is 50% more than the old lab (16 GB is supported but slower)the Intel core i7-970 CPU gives 100% more MHz than the old Q6600. They are much more expensive, truth be told. But being Westmere generation, they support vSphere4.1 features like DirectPath I/O and Fault Tolerance.I can re-use the PCIe dual gigabit adapters I had in the old lab.
One real problem so far: in BIOS v100, I couldn't change any setting without rendering t…

Comparing bluetooth carkits

Bluetooth carkits come in three main categories: those with bluetooth HSP, those with bluetooth HFP, and ones that do bluetooth SAP. Some implement multiple of these profiles and allow you to choose.

HSP (head set profile) is the simplest profile: your carkit is basically a speaker-microphone combo, and will play the received audio and send your voice to the telephone. The telephone connects to the cellular network and handles the call. HSP is commonly used in bluetooth earpieces.
HFP (hands free profile) is the most common protocol in carkits with a display: your phone still handles the call, and the carkit provides the two-way audio function just like HSP. But the carkit also has basic control over the phone: it can access the received/dialled/missed call lists. It can also instruct the phone to dial a number, to accept or to reject an incoming call. Most carkits also access the phonebook.
SAP (SIM access profile, also known as rSAP or SIM) is the most complex of the three: this carkit…

Am I running in a VMware virtual machine ?

That's an easy question, and the answer isn't too difficult either:
Query the MAC address of the local network card. If it starts with "00:50:56", that indicates that it's a VMware VM. List devices on the PCI bus. If there's devices with vendor ID 15ad, you can be sure that this is a VMware VM.Look at the BIOS information (DMI). If you see Manufacturer "VMware, Inc", and the serial number starts with "VMware", and the Product Name is "VMware Virtual Platform", that's again very clear.In a typical VMware VM, you should find the VMware Tools running: the vmmemctl driver, maybe the vmxnet network card driver maybe, the vmware-guestd or VMwareUser or VMwareTray processes, ...And here's a practical list of tools you'd use to run these checks:
use "/sbin/ifconfig eth0" on Linux, "ipconfig /all" on Windows. You can do this as a normal user.use "/sbin/lspci" on Linux. Also possible as a normal use…

DIY Optical Parking Sensor upgrade

My 2008 Volkswagen Touran came with Parking Distance Control, beeping to indicate the remaining distance to objects when the car is in reverse gear. The control unit that I had was of an old type, and I had the impression it wasn't functioning 100%. So I got a new module from Kufatec, to replace the old one.
Kufatec explains that you need to run a wire from the back of the vehicle to the front, but as it turns out this is not necessary when the old module is already at address 10 on the CANBUS network. If the old module is at address 76, then you do need the new wiring. I already ran the wire to the front of the vehicle and connected it before realizing that I didn't need it. Result: countless electronics error messages in the on-board diagnostics. It could have been a simple drop-in replacement, if the documentation would have explained this correctly. Clearing all the error messages took quire some time, but was succesful in the end.
The new module works well now, and as a bon…

death grip

Yes, my phone has a "death grip". No, it's not a v4 iPhone, it's a Nokia E71. But the comforting thing is, Nokia documented it in the manual all along (page 16/17). That indicates that they knew this while designing the phone. That figures, because covering/connecting both antenna areas would require a very awkward grip. Whereas the reaction Apple displayed recently has a distinct "Oh f*ck, we forgot about that" feel to it.

VMware tools on RHEL/CentOS: the easy way

VMware pre-compiles the VMware tools for selected OS kernels. The stock RHEL kernels are included, but not the intermediate updates. If you can live with that, you can simply add the VMware tools YUM repository:
# cd /etc/yum.repos.d/
# wget
and download the VMware RPM signing key
# cd /etc/pki/rpm-gpg
# wget

Then install the tools packages:
# yum install vmware-tools-nox
# yum install vmware-tools

vCenter will report the tools version as "Unmanaged" rather than "OK", but you have heartbeat (so HA and alarms can detect guest OS crashes), balloon driver, etc.

DIY carkit replacement

The factory-installed UHV carkit[0] in my Volkswagen Touran worked well with a normal cellphone-holder, but in combination with the Bluetooth Touch Adapter[1], it became a very unreliable combination. I've read many succes stories with the Touch Adapter, but the flaky communication between the TA and the UHV was a nightmare sometimes.

To fix that, I ordered a replacement carkit from Kufatec[2]. The module replaces the simple factory UHV with a newer one (also original from VW). The new module does not only bluetooth sound, but also address book, call lists, etc. It doesn't offer cellphone specific holders for power and antenna connections.

Installation was quite easy, as there are many howto's describing VW Low-to-Premium modding. In the Touran (1T0), the UHV is under the passenger seat, and requires removal of the lowest drawer. A T15 Torx screwdriver does the trick. Then you can open the floor cover, get the original module out, and the new module in. Replace the drawer, a…

QNAP 459U-RP: first impressions

I recently added a dedicated storage box to my lab environment. After a week these are my first impressions:

Small. I needed a shallow rack-mountable device, and this one is perfect, only about 50cm deep.Fast. I knew that a NAS device like this wouldn't be the speed king of the storage world, but I'm pleasantly surprised.
Open software. It runs Linux, you get SSH access to your device, and you can add packages if you want. Evidently, I added tools like dstat to keep an eye on things.Compatibility. Used it from Windows Vista, VMware vSphere, and Linux (CentOS and others). No problems at all.Cheap. I could have gone for an EMC Symmetrix instead, but decided against it :-)
Fragile. Just a bit. The SATA ports of the disk drives slide directly in sata plugs inside the device. I hope I won't have to re-plug drives all too often.Not all operations happen online. QNAP advertises RAID1 to RAID5 migration, and it does that, by using one of the mirrored drives and the new drive …

Scanning a host reconfigures the cluster. What and why ?

On vSphere4, when you scan a host (ESX or ESXi) for updates, you'll see a task "reconfigure cluster" appear automatically. Ever wondered what that task does ? The "tasks & events" tab doesn't give you any clues, but if you happen to be looking at the "DRS" pane while the task is running, you'll see it: scanning a host in a cluster, automatically disables DPM for the duration of the scan. My guess is that this is to prevent DPM from putting a host in standby mode while it is being scanned.

Buy VMware, get SuSE

Anyone following VMware's enterprise offerings will know that VMware has been "in bed" with Red Hat for a long time. The "service console" of the ESX product has been Red Hat Linux and Red Hat Enterprise Linux based since the beginning, and many of the virtual appliance-based products (VMware Data Recovery e.g.) are RHEL or CentOS based.
But now VMware comes with a partnership announcement with Novell/SuSE, not Red Hat ! Anyone buying vSphere will get SLES for free, including patches ! Note, the offer isn't fully up just yet, they forecast a GA launch in 3Q2010. But anyone buying vSphere starting today (june 9th) will be in on the offer when it launches. Beware, "free" doesn't include support, from what I read in the press release. But SLES support will be available through VMware.
A lot of questions are waiting for an answer:
Will this deal impact the place RHEL and CentOS held in the VMware solution stack ?What will be the response from Red Hat…

Which ESX version am I running on ?

Your Linux runs on a VMware VM, but which ESX version is it ? You can see for yourself (as already explained in an earlier post on this blog). Run "dmidecode" and look at lines 10, 11 and 12. The list has been updated with current info:
ESX 2.5 - BIOS Release Date: 04/21/2004 - Address 0xE8480 - Size 97152 bytes
ESX 3.0 - BIOS Release Date: 04/17/2006 - Address 0xE7C70 - Size 99216 bytes
ESX 3.5 - BIOS Release Date: 01/30/2008 - Address 0xE7910 - Size 100080 bytes
ESX 4 - BIOS Release Date: 08/15/2008 - Address 0xEA6C0 - Size 88384 bytes
ESX 4U1 - BIOS Release Date: 09/22/2009 - Address 0xEA550 - Size 88752 bytes

Stating the obvious

ICT website Computable runs a series of articles on Linux. The first article focuses on "hidden costs when migrating to Linux". In my experience, any project has hidden costs, and certainly so if preparation hasn't been done thoroughly, and with the necessary experience and know-how. There's plenty of experience available from various consultancy providers, use it !
PS don't forget to read the comments below the article as well.

Cisco SLM2024 and Firefox

I don't know what got me to search for new firmware for my Linksys (now Cisco) SLM2024. But I did, and found version (upgrade from the previous 1.0.1). Aside from the web interface, there's no obvious changes. It is now branded Cisco, rather than Linksys. But the most important change for me wasn't in the release notes: I can now manage my gigabit switch using Firefox ! (tested with Firefox 3.6.2 on Windows)

HZ divider effect on timer interrupt overhead

Red Hat and related distro's (like CentOS) use 1000 timer interrupts per second, per CPU core or thread (this is called the "HZ value" inside the kernel). Because this causes a lot of extra work in case of virtualization, and caused (past tense since RHEL 5.4!) problems with timekeeping, the "divider" kernel parameter has been introduced. For example, by booting with "divider=10", the kernel uses 100 timer interrupts instead of 1000, and "divider=25" means 40 timer interrupts per second.
I did a little test today to see what difference that makes when running CentOS5.4 on vSphere. Tests were done with the current 2.6.18-164.11.1.el5 x86_64 kernel in a single vCPU VM. These are the results from my test environment:
standard settings: HZ=1000: 60 MHz cycles used when idle.divider=2: HZ=500: 36 MHz cycles used when idle.
divider=5: HZ=200: 25 MHz cycles used when idle.
divider=10: HZ=100: 20 MHz cycles used when idle.divider=25: HZ=40: around 10-15…

Volkswagen UHV bluetooth touch adapter & its problems

My Volkswagen car has the "universal cellphone preparation" UHV built-in. This is the main part of a car kit, but requires an additional adapter for connecting to a cellphone. At first, I was using an adapter for my good old Nokia 6310, even after I changed to the Nokia E71. Connecting was easy: pair the phone with the "VW UHV" bluetooth entity, and done. This has the phone connected to the car kit at all times, so even non-call-related functions use the car audio system (e.g. voice recognition).
But progress will have its way, no matter what happens. So in comes the "bluetooth touch adapter". Instead of a phone-specific adapter, this is a small touchscreen device that slots into the UHV dashboard mount. Connecting a phone is very different now:
the Bluetooth Touch Adapter connects to the "VW UHV" device via bluetooth
the phone connects to "Touch Adapter" device, also via bluetoothThe device doesn't allow step 2 if step 1 didn't s…

Preparing Linux for optimal thin provisioning and deduplication

VMware and disk-array based thin provisioning can help you economize on disk space, just as disk-array based deduplication can. But how to take optimal advantage of those techniques ? Executive summary:
dd if=/dev/zero of=/tmp/tempfile.zeroes ; rm -f /tmp/tempfile.zeroes
First of all, both thin provisioning and deduplication work transparently. But you can make them work better with a little bit of work. There's three different types of blocks on your (virtual) disk that we need to distinguish: data blocks, old data blocks, and empty blocks.
Data blocks and empty blocks are what they are, and can't be influenced. Data blocks contain data for files that are on your filesystem. Empty blocks are empty, have never been written to with any real data, so their blank, contain only zeroes.
It's the "old data" blocks that we can improve: they contain data that used to be part of a file. The file got deleted, but the contents are still there.
Overwriting those blocks with zeroe…

DLNA with Linux and a Yamaha RX-V2065

The Yamaha RX-V2065 is the first non-PC-based surround sound system I own. In addition to playing everything radio and hdmi-based, this receiver has an Ethernet connection. It can stream a long list of Internet radio stations, and it can find DLNA media servers on the local network to play various audio formats (no Ogg Vorbis though).
I've got my collection of some 400 CD's in mp3 format stored on my CentOS Linux fileserver, so obviously I wanted to access these files from the RX-V2065.
First attempt: Coherence on the CentOS 5.4 fileserver. Because of missing dependencies, only the FSStore backend worked. Streaming worked, but no Track/Artist/Album fields were passed through.
Second attempt: Coherence 0.6.4 on Ubuntu 9.10 in a VM, with the mp3 catalog mounted via NFS. Now the FSStore backend still works, and the MediaDB backend too. This second backend does provide Track/Artist/Album information, and even Album Cover art, downloaded using albumart-qt 1.6.6 on the CentOS s…

ADSL speed

ADSL has got me stumped. A couple of months ago, Scarlet (aka Belgacom) claimed that even though my ADSL2 modem synced at around 6Mbps, it wasn't unusual that the maximum downstream data rate was 1Mbps, because of the distance from the modem to the ADSL concentrator apparatus thing. Even though I was very sure that it had been 3+Mbps over a year ago.
Today I notice, from the corner of my eye, the download speed of a virtual appliance I was fetching: 500+ KBps, or a good 5 Mbps. Sync rate of my modem is still 6Mbps.
Was something changed at the Scarlet/Belgacom side ? If yes, why ? Or am I blessed by a unique and unexplained cosmic alignment of some sort ? I just hope it doesn't go down again. Maybe I should keep in my bookmarks.

VMware confirms strategy

Open source email and calendar solution provider Zimbra got acquired by VMware recently. While there's lots of angles to this story, it also confirms an important part of VMware's strategy: bigger and bigger hardware, running a powerful hypervisor, running thin and optimized OSes, running applications that perform business functions.
To enable perfect mobility and ease-of-use, the OS and application will be packaged into so-called Virtual Appliances or vApps.
Making the OS thinner is essential for this strategy, and goes against the core beliefs of competitor Microsoft. The succes of the vApp concept will be a deciding factor in the battle between these two giants.

10% discount on VCP4 exam

VMware has announced a 6-month promotion, where students who participated in an official VMware training can get 10% off the regular price of the VCP4 exam, until the end of june 2010. If you plan on doing the VCP4 certification, contact your instructor as soon as possible. He'll give you a personal promotion code that you can use when registering for the VCP4 exam at Pearson Vue. (Yes, that instructor might be me ! ;-))