Enabling SNMP on my ADSL router

Posted on By Mark Wilson
This content is 15 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

I’ve been playing around with some network monitoring and management tools on my home network and so have been busily enabling Simple Network Management Protocol (SNMP) on a number of my devices, including my elderly Solwise SAR110 ADSL modem/router; however the router’s web interface doesn’t seem to have the ability to configure the SNMP agent.

I asked how to do this on the Solwise forums and the response was to use the command line. Sure enough, I located the Solwise SAR110 Advanced Reference Guide telnetted to the router’s internal interface, logged on, and issued the following commands:

create snmp comm community public ro

(to create a community called public with read only access.)

create snmp host community public ip ipaddress

(to allow a specified IP address to interrogate the device using the public community.)

get snmp host confirmed that the settings were correct.

Enabling traps to inform the SNMP manager of any events was already enabled by default (confirmed using get snmp trap); however the command would have been modify snmp trap enable (or modify snmp trap disable to disable traps).

In order to test the configuration, I ran Noël Danjou’s SNMPTest utility. This confirmed that my router was accessible via SNMP; although I’m not sure if the trap functionality is working as it should be… I certainly didn’t see any evidence of the “System up” trap being sent after resetting the router.

Finally, once I was sure that everything was working as expected, I issued the commit command to save the changes (and re-ran the tests to see if that was why the traps hadn’t worked).

It’s not very likely that anyone reading this blog is using such an ancient device; however the general principle holds true for many consumer devices. If the web interface doesn’t let you do what you want, see if there is command line access, typically via telnet or ssh.

Which service pack level is Windows Server 2008 R2 at?

Posted on By Mark Wilson
This content is 15 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

Those that remember Windows Server 2003 R2 may recall that it shipped on two disks: the first contained Windows Server 2003 with SP1 integrated; and the second contained the R2 features. When Windows Server 2003 SP2 shipped, it was equally applicable to Windows Server 2003 and to Windows Server 2003 R2. Simple.

With Windows Server 2008, it shipped with service pack 1 included, in line with it’s client operating system sibling – Windows Vista. When service pack 2 was released, it applied to both Windows Server 2008 and to Windows Vista. Still with me?

Today, one of my colleagues asked a question of me – what service pack level does Windows Server 2008 R2 sit at – SP1, SP2, or both (i.e. multiple versions). The answer is neither. Unlike Windows Server 2003 R2, which was kind of linked to Windows XP, but not really, Windows Server 2008 R2 and Windows 7 are very closely related. Windows Server 2008 R2 doesn’t actually display a service pack level in its system properties and I would expect the first service pack for Windows 7 to be equally applicable to Windows Server 2008 R2 (although I haven’t seen any information from Microsoft to confirm this). What’s not clear is whether the first service pack for Windows Server 2008 R2 and Windows 7 will also be service pack 3 for Windows Server 2008 and Vista? I suspect not and would expect Windows Server 2008 and Windows Server 2008 R2 to take divergent paths from a service pack perspective. Indeed, it could be argued that service packs are less relevant in these days of continuous updates. At the time of writing, the Windows service pack roadmap simply says that the “Next Update and Estimated Date of Availability” for Windows Server 2008 is “To be determined” and there is no mention of Windows 7 or Server 2008 R2.

So, three consecutive operating system releases with three different combinations of release naming and service pack application… not surprisingly resulting in a lot of confused people. For more information on the mess that is Microsoft approach to major releases, update releases, service packs and feature packs, check out the Windows Server product roadmap.

Installing the Ancestry.co.uk Enhanced Image Viewer application on Windows 7 (x64)

Posted on By Mark Wilson
This content is 15 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

A couple of weeks back, I started to investigate my family tree. Spurred on my a combination of recent personal events I switched the half-hearted attempt that I’d made at genesreunited.co.uk over to ancestry.co.uk and the 14 day trial was enough to convince me that it was a good tool for researching my family history.

Transferring my tree was easy enough – there is a de facto file format used by genealogists called GEDCOM and both sites supported it, but as I got stuck into researching the tree I found that I was having difficulty installing the Enhanced Image Viewer ActiveX control that Ancestry uses to display certain documents. To be fair to Ancestry, I run Windows 7 (not yet generally available) – but they only officially support IE7 (IE8 has been around for a while yet) and push people towards Firefox if they are having problems. Firefox is OK, but installing a new browser just to access one feature on a website is also a little extreme. I was sure there was a way… and eventually (with Ancestry’s help), I got there.

My problem was that (using 32-bit Internet Explorer) I could access a page that wanted to load the Enhanced Image Viewer and I could download and run the installer; however setup failed stating that:

Setup failed – contact customer support

Windows then detected a problem with the installation but, following advice on the Ancestry website I told it that the installation was successful and it allows me to continue. After returning to Ancestry, I was presented with a message stating that:

The Enhanced Image Viewer is not installed on this machine. For the best experience, please click here to download the Enhanced Image Viewer or click here to view this image using the Basic Image Viewer.

The Basic Image Viewer seems to work OK but the very existence of an “enhanced” viewer suggests that there is something there that I’m missing (and this is a subscription website after all)!

So, here’s what I tried that didn’t work:

  1. Enabling the ActiveX control using Internet Explorer to manage add-ins (it wasn’t there to enable).
  2. Manually downloading and installing the Enhanced Image viewer (failed to register).
  3. Manually uninstalling the Enhanced Viewer (it was not there as it never successfully installed).

In the end, I broke all good security practices by logging on as administrator (instead of running the installer as an administrator), and turning off UAC, after which the viewer installed as it should. Clearly this application was very badly developed (it seems not to follow any modern application development standards) but at least I got it installed!

One final word of warning – and this one is non-technical – researching your family tree can quickly become addictive (my wife refers to it as my latest “time Hoover”).

Connecting multiple ReadyNAS devices to a single UPS

Posted on By Mark Wilson
This content is 15 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

It seems to be ReadyNAS week at markwilson.it because that’s what I’ve spent the last couple of days working with but the ReadyNAS really is a stonking piece of hardware (think of it as a £150 Linux box with built-in X-RAID) and mine will soon be providing the storage for a Windows Home Server VM (yes, I know the ReadyNAS can do loads of the things that WHS can, but I work with Microsoft products and it’s about time I had a serious look at WHS).

Anyway, my ReadyNASes are running off an APC Smart-UPS 1500 but only one of them has the USB connection to monitor the UPS status. It turns out that’s not a problem as the latest versions of the ReadyNAS software (RAIDiator) allow one ReadyNAS to act as a UPS status server for the others.

I think this needs at least v4.1.5 of RAIDiator (my ReadyNAS “UPS client” shipped with v4.1.4 and I updated it to v4.1.6, meanwhile the “UPS server” is running v4.1.5) but there is an option on the Power page in FrontView (the ReadyNAS web administration console) to define hosts that are allowed to monitor the attached UPS (where a physical connection to the UPS exists).

ReadyNAS UPS server

Similarly, on a ReadyNAS that is not physically connected to a UPS, it is possible to specify the IP address of a ReadyNAS that is connected to the UPS.

ReadyNAS UPS client

With these settings enabled, both ReadyNAS devices can cleanly shutdown in the event of a power failure.

I wonder if my Windows Server 2008 host can also monitor the ReadyNAS and shut itself down in the event of power loss too…

What does your digital tattoo say about you?

Posted on By Mark Wilson
This content is 15 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

We’ve all heard of employers Googling prospective (and current) employees to check out their history/online status and there’s the recent story that went viral about someone who forgot she’d added her Manager on Facebook before bitching about her job (needless to say she didn’t have a job when he read what she had to say). Then there’s the story of the Australian call centre worker who was too drunk to work and pulled a sickie… only to be busted on Facebook.

Maybe these things sound like something that happens to someone else – none of us would be that stupid, would we?

Actually, it can happens to the best of us, although maybe not in quite an extreme manner. I’ve become a bit of a Twitter evangelist at work (David Cameron might say that makes me something else…) and, after one of my colleagues suggested that my new manager check out my feed as an example of effective technical knowledge sharing, I hastily checked for any potential lapses of judgment. I did actually remove an update that was probably OK, but I didn’t want to chance it.

Generally I’m pretty careful about what I say online. I never name my family members or give out my address, family photos are only available to a select group of people, I don’t often mention the name of the town where I live (although this blog is geotagged) and I am very careful to avoid mixing the details of my day job too closely with this website (technical knowledge sharing is fine… company, partner and customer details are not).

Digital tattooIt seems that there is a generation of Internet users who are a little more blasé though and Symantec are advising consumers against the dangers of sharing their personal information on the ‘net, referring to a “digital tattoo” (described as “the amount of personal information which can be easily found through search engines by a potential or current employer, friends or acquaintances, or anyone else who has malicious intent”).

The digital tattoo term seems particularly apt because there is a misconception that, once deleted, information is removed from the ‘net but that is rarely the case. Just like a physical (skin) tattoo, removing a digital tattoo can be extremely difficult with the effects including hindered job prospects and identity theft. Symantec’s survey revealed that 31% of under-25s would like to erase some of their personal information online. Nearly two-thirds have uploaded personal photographs and private details such as postcodes (79%) and phone numbers (48%) but, worryingly, one-in-ten under-25s have put their bank details online (not including online purchases) and one-in-20 have even noted their passport number!

Of course, there are positive sides to social networking – I personally have benefited from an improved relationship with several technology vendors as a result of this blog/my Twitter feed and it’s also helped me to expand my professional network (backed up with sites like LinkedIn and, to a lesser extent, Facebook). What seems clear is that there is a balance to be struck and today’s young people have clearly not been sufficiently educated about the dangers of life in an online society.

Physical disks can only be added to Hyper-V VMs when the disk is offline

Posted on By Mark Wilson
This content is 15 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

I don’t often work with passthrough disks in Hyper-V but, after configuring my Netgear ReadyNAS as an iSCSI target earlier this evening, I wanted to use it as storage for a new virtual machine. Try as I might, I could not get Hyper-V Manager to accept a physical disk as a target, despite having tried both SCSI and IDE disk controllers. Then I read the information text next to the Physical hard disk dropdown in the VM settings:

“If the physical hard disk you want to use is not listed, make sure that the disk is offline. Use Disk Management on the physical computer to manage physical hard disks.”

Doh! a classic case of RTFM… (my excuse is that it’s getting late here). After taking the disk offline I could select it and attach it to the virtual machine.

Creating an iSCSI target on a Netgear ReadyNAS

Posted on By Mark Wilson
This content is 15 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

A few months ago, I wrote that I was looking for an iSCSI target add-on for my Netgear ReadyNAS Duo. I asked if such an add-on was available on Netgear’s ReadyNAS community forums; however it seems that these are not really a true indication of what is available and the moderators are heavily biased by what Netgear supports, rather than what can be done. Thanks to Garry Martin, who pointed me in the direction of Stefan Rubner’s ReadyNAS port of the iSCSI Enterprise Target Project, I now have a ReadyNAS acting as an iSCSI target.

I have a lot of data on my first ReadyNAS and, even though I backed it all up to a new 1.5TB drive in my server (which will eventually be swapped into the the ReadyNAS as part of the next X-RAID upgrade), I wasn’t prepared to risk losing it so I bought a second ReadyNAS to act as an iSCSI target for serving virtual machine images. In short, don’t run this on your ReadyNAS unless you are reasonably confident at a Linux command prompt and you have a backup of your data. This worked for me but your mileage may vary – and, if it all goes wrong and takes your data with it, please don’t blame me.

First up, I updated my ReadyNAS to the latest software release (at the time of writing, that’s RAIDiator version 4.1.6). Next, I enabled SSH access using the Updates page in FrontView with the EnableRootSSH and ToggleSSH addons (note that these do not actually install any user interface elements: EnableRootSSH does exactly what it says, and when it’s complete the root password will be set to match the admin password; ToggleSSH will enable/disable SSH each time the update is run).

The next step was to install the latest stable version (v0.4.17-1.0.1) of Stefan Rubner’s iSCSI target add-on for ReadyNAS (as for EnableRootSSH and ToggleSSH, it is simply applied as an update in FrontView).

With SSH enabled on the ReadyNAS, I switched to using a Mac (as it has a Unix command prompt which includes an SSH client) but any Unix/Linux PC, or a Windows PC running something like PuTTY will work too:

ssh root@ipaddress

After changing directory to /etc (cd /etc), I checked for an existing ietd.conf file and found that there was an empty one there as ls-al ie* returned:

-rw-r–r–    1 admin    admin           0 Dec  3  2008 ietd.conf

I renamed this (mv ietd.conf ietd.conf.original) and downloaded a pre-configured version with wget http://readynasfreeware.org/gf/download/docmanfileversion/3/81/ietd.conf before editing the first line (vi ietd.conf) to change the IQN for the iSCSI target (a vi cheat sheet might come in useful here).

As noted in the installation instructions, the most important part of this file is the Lun 0 Path=/c/iscsi_0,Type=fileio entry. I was happy with this filename, but it can be edited if required. Next, I created a 250GB file to act as this iSCSI LUN using dd if=/dev/zero of=/c/iscsi_0 bs=10485760 count=25600. Beware, this takes a long time (I went to the pub, came back, wrote a good chunk of this blog post and it was still chugging away for just over 4 hours; however it’s possible to get some idea of progress by watching the amount of free space reported in FrontView).

At this point, I began to deviate from the installation notes – attempting to run /etc/init.d/rfw-iscsi-target start failed so I rebooted the ReadyNAS but when I checked the Installed Add-ons page in FrontView I saw that the iSCSI target was already running although the target was listed as NOT_FOUND and clicking the Configure Targets button seemed to have no effect (I later found that was an IE8 issue – the button produced a pop-up when I ran it from Safari over on my Mac and presumably would have worked in another browser on Windows too).

I changed the target name to /c/iscsi_0, saved the changes, and restarted the ReadyNAS again (just to be sure, although I could have restarted the service from the command line), checking that there was a green light next to the iSCSI target service in FrontView (also running /etc/init.d/rfw-iscsi-target status on the command line).

ReadyNAS iSCSI Target add-on configuration

With the target running, I switched to my client (a Windows Server 2008 computer) and ran the iSCSI initiator, adding a portal on the Discovery tab (using the IP address of the ReadyNAS box and the default port of 3260), then switching to the Targets tab and clicking the Refresh button. I selected my target and clicked Log On… waiting with baited breath.

Windows iSCSI initiator Discovery tabWindows iSCSI initiator Discovery tab

iSCSI target exposed in Disk Management

No error messages indicated that everything was working so I switched to Server Manager and saw a new 250GB unallocated disk in Disk Management, which I then brought online and initialised.

Finally, I updated /etc/rc6.d/S99reboot to include /etc/init.d/rfw-iscsi-target stop just before the line that says # Save the last 5 ecounters by date.

ReadyNAS Duo with no available disk space

Posted on By Mark Wilson
This content is 15 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

My new Netgear ReadyNAS Duo was delivered at lunchtime today. This is the second ReadyNAS Duo I’ve bought and the first is happily serving media and other files to my home network, whereas this one is intended to be hacked so that it can become an inexpensive iSCSI target (I hope).

I bought the RND2000 (i.e. the model with no disks installed) as I already have a spare 500MB disk from the first ReadyNAS (which has since been upgraded to use a pair of 1TB Seagate Barracudas) and NetGear’s current offer of a free hard drive will allow me to make this single disk one half of a RAID 1 mirror. After setting up the device via the web interface (FrontView), I discovered that the disk was detected as full with 0MB (0%) of 0GB used.

There were no options to erase the disk, but I had previously been using this disk in a Windows Server computer so I mounted it on a Windows PC where it was recognised and I was able to delete the existing partition. After putting the disk back into the ReadyNAS, the RAIDar utility showed that it was creating a volume (eventually I could see that Volume C: had been created, with 0% of 461GB used) although it seems that I had also wiped my configuration along with the NTFS partition (that was straightforward enough to set up again).

RAIDar showing new volume creation on a ReadyNAS

Now I have the ReadyNAS up and running it’s time to have a go at setting it up for iSCSI… watch this space.

Drive speeds for ATA, USB Flash, SDHC and CF

Posted on By Mark Wilson
This content is 15 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

Guest Post[In recent weeks, there have been a number of posts on this blog looking at the Hyper-V developer workstation proof of concept (booting from a .VHD on a flash drive) that I knocked up for my colleague Garry Martin. This post is slightly different in that Garry did the legwork and provided me with some notes to publish in his name. So, with a little editorial input from yours truly, here are Garry’s notes on drive speeds for ATA, USB Flash, SDHC and CF.]

Card speed is usually specified in “x” ratings. This gives the data rate as a multiple of the data rate of the first CD-ROMs which ran at 150kB/s. Thus a 133x SDHC card is running at 133 * 150kB/s = ~20MB/s.

Most premium SDHC cards on the market today run at 200x (30MB/s) although a few 233x (~35MB/s) cards have started to appear.

In contrast, most premium CF cards on the market today run at 300x, or ~45MB/s, roughly equivalent to a modern 80GB laptop hard drive.

The faster USB flash drives currently run at somewhere between 200x and 233x (30MB/s and 35MB/s). Examples are the Corsair Flash Voyager GT 4GB, the OCZ ATV Turbo 4GB and the Lexar JumpDrive Lightning 4GB.

Looking at pricing for the various media types:

Device Approximate price to purchase (UK prices, August 2009)
SanDisk Extreme III SDHC 4GB (200x) £20
SanDisk Extreme III SDHC 8GB (200x) £50
SanDisk Extreme III 4GB CompactFlash (200x) £30
Corsair Flash Voyager GT 4GB (233x) £35
OCZ ATV Turbo 4GB (233x) £35
Lexar JumpDrive Lightning 4GB (200x) £35

[I’m still playing around with flash for my USB boot scenario (especially as an SDHC card will sit nicely in my notebook PC’s card reader slot) but, ironically, for a project that started out looking at booting from a USB flash drive, we will probably settle on the use of external hard disks. This isn’t for reasons of performance but because the internal disks that would have stored the VMs are encrypted – whereas with a USB-bootable hard disk we can store the VHDs for our VM workloads and the parent partition’s bootable VHD. (BitLocker and hibernation are two Windows features that boot from VHD does not support.)]