Archives for: 2011

Bandwidth

05/03/11 | by admin [mail] | Categories: Hardware, Networking

Never underestimate the bandwidth of a station wagon full of tapes.
-- Dr. Warren Jackson, Director, UTCS

Many moons ago, on the original AmigaOne beta testers mail list, one of the mailers referred to their gigabit sneaker net. An external hard drive which they would walk home from the office with.

In networking terms, bandwidth is the capacity of the network to transfer data. If you ignore the underlying medium (which really doesn't matter), you can see that sneakernets often have very high bandwidth. Take a 3TB external drive. Over 10 mins (600s) the unidirectional bandwidth is 50 gigabit/s (assuming 10bits/byte). Of course, if you also need to transfer the data from a system to the 3TB drive, and then to another system, bandwidth is greatly reduced.

But back to the quote. Let's assume some 1.5TB LTO-5 tapes. Let's assume a rather conservative capacity of the station wagon of 5000 tapes. That's 7.5 petabytes. Over an hour, that would be about 16terabit/s, or Sydney to Melbourne about 1.5tbps. Which doesn't compare too badly to a fibre optic link.

Of course, sneakernets or stationwagon-nets may have high bandwidth, but there are two big issues to consider. One is that these nets are half duplex. If you require a network technology that allows you to communicate back and forth a lot, something involving time critical dynamic data processing (like gaming), it's not so great. The other thing to consider is transferring to transport medium from the system. Maybe with a hard drive, this is not such a problem. You could keep your home folder on an external hard drive or, maybe the whole system on a removable bay. But for tape, which is necessarily an offline medium, you lose a lot of time in the transfer.

However, if what you need to do a one transfer of a large amount of data, sneakernet or car net, will usually outperform ADSL, SHDSL or even 10mbit fibre.

Permalink

Macs I have owned

15/02/11 | by admin [mail] | Categories: Hardware, Mac

For a while (about 6 years) I was buying and selling on eBay to earn a little cash, and indulge my interests in hardware. As a result, I managed to own, for periods of time, a variety of Macs.

It's just a list. And I must admit, I feel a little like this guy.

Interesting, is that I've only ever owned 1 68k Mac (I have a long standing project on the backburner to get MacOS 8.1 running on a 68060 Amiga).

Centris 610

Quite a few nubus Macs. At one point I was going to build a Beowulf cluster of 6100s, inspired by this guy. But discoved that only 2 of the 5 I had acquired worked, so not much of a cluster. I upgraded one of them to a G4, making it one of the slowest G4 macs in the world (I think 300Mhz, on a 66MHz 6100), and scored some 128Mb SIMMs to upgrade it to 264Mb. There are rumours of 256Mb SIMMs, but I've never seen one.

Power Macintosh 6100
Power Macintosh 7100

I had a quite a few PCI Power Macintoshes, and various bits and pieces for them, including a ZIF carrier card and a few G3 accelerators. I had one with the AV card, and used it a few times for live video capture. I wouldn't mind getting a 9600 (or maybe a 7500), and upgrading it a bit to get OSX running on it. I think, theoretically, you can get 10.5 running on one.

Power Macintosh 7300
Power Macintosh 7500
Power Macintosh 7600
Power Macintosh 8500
Power Macintosh 8600
Power Macintosh 9600

And quite a few beige G3's, which were good back when G4s were still too much. The Beiges allowed you to use IDE drives, the CPU was on a ZIF and easily replaceable/overclockable, had built in everything plus 3 PCI slots. I had one running a Voodoo5 at one point, as well as Radeon 7000, firewire and USB2.

Power Macintosh G3 desktop
Power Macintosh G3 minitower

PowerBook G3s. I managed to get a near mint PowerBook G3 Pismo back in 2004. I still think it's the best laptop Apple made. The case design is far more beautiful (sensuous even) than anything else they've made, had most of what you'd want in a laptop for its time (and quite a few years after, too), and could be relatively easily upgraded. It had a cool feature which allowed you to swap out the optical drive for another drive (floppy, zip, hard drive) or second battery. And had a CardBus slot for expansion.
I upgraded it to 768MB RAM, 500MHz G3, 80GB hard drive, and a CardBus Airport compatible 802.11g card.
I sold it to pay for an overseas trip, and regret it still.

PowerBook G3 Wallstreet
PowerBook G3 Pismo

Very briefly had a 5 flavours iMac G3 tray loader. The only G3 iMac I've owned, and only one of two iMacs I've owned.

iMac G3 tray loader

Nearly every PowerMac G4 they made, except the later Mirror Door and Firewire 800 models which never seemed to be good value for money. The PowerMac G4s were the computers I started the transition to Mac from Windows on. I bought an AGP, which I upgraded and sold, then bought a Digital Audio, which I upgraded and sold, and then ended up with 933MHz Quicksilver, which I kept until I got my G5. I managed to upgrade from the AGP to the G5 without ever spending more than I sold the old computer for.

The Digital Audio was what I kept the longest. I had a 733MHz model, which was the top end in its day. The DA had a few advantages, basically the same as the QS (QS 2002 supported drives larger than 128GB), cheaper, a 133MHz bus, gigabit ethernet and a 4x AGP slot which meant more upgrades possible for the Video card. The only downside was the 3 RAM slots, although in its day 1.5GB was more than enough. I got around the 128GB drive limit by using a SATA card, with SATA drives.

There were quite a few upgrades along the way, flashed and modified G5 Radeons, SATA cards, PCI airport compatible cards, USB 2 cards, CPU upgrades, dual screens. I think I ended up with dual 21" screens. I still have a couple that have I got free or very cheap. Currently, I am upgrading a Gigabit with dual 7447a CPUs.

PowerMac G4 PCI
PowerMac G4 AGP
PowerMac G4 Gigabit
PowerMac G4 Digital Audio
PowerMac G4 Quicksilver
PowerMac G4 Quicksilver 2002

PowerMac G4 Mirror Drive Door (bought dead for parts, and never worked)

1 eMac, briefly. At the time I bought it I had a G4 with a 21 inch screen, so 17inch was not so impressive.

eMac 1GHz

Another bargain. All it needed was a new power adaptor. Kept this for some time, until I got a cheap, slightly faulty, white MacBook.

PowerBook G4 1.5GHz 15"

Mac Mini's are good a 2nd and 3rd computers. The G4 had a couple of flaws, some of which persist, firewire 400 and one 10/100 NIC. I think the Mac Mini's could benefit from dual NICs and maybe eSATA, although USB3 might do the trick on both counts, particularly in the server version.

Mac Mini G4 1.42GHz

Very cheap Xserves. I still have the G4 Dual, but had to scavenge the PowerSupply to repair another Xserve G4.

Xserve 1.33 G4 Dual

The dual 2GHz G5 was my first G5, and I had it from late 06 to late 07. No major upgrades apart from a 9800Pro, 4GB RAM, airport/bluetooth, and several hard drive upgrades. It was bought faulty, and repaired. I sold it anticipating the rev B Mac Pro was imminent, but ended up buying a very cheap 1.6 a month or two later to use until the 2008 Mac Pro arrived.

PowerMac G5 1.6GHz
PowerMac G5 2GHz dual

Permalink

Another weekend hacking away

13/02/11 | by admin [mail] | Categories: Hardware

So, I found a nice book called Linux Sysadmin Recipes which covers a range of practical solutions and tools for administering Linux (and *nix) servers. It's the kind of good practical hints and tips that are really needed.

Anyway, one of the things Juliet Kemp suggests is to set up a wiki for managing documentation. A wiki has a number of strengths that make it quite useful for this. It is web accessible, meaning you can access it from any web browsers (more or less), and perhaps more usefully, make it accessible (in full or part) to other IT staff and end users. So, you can do something useful like document how to set up an email client, or VPN service, and your junior IT staffers and end users can read the info from their web browser. And by putting the info in one place, you can update it in one place, and everyone has access to the current version. And you can keep the more complex internal documents restricted to the appropriate staff.

The wiki can act as documentation, and knowledge base, and different users can be given different access. You can integrate authentication into your existing LDAP (or other directory service) and make it internal and/or internet facing. If you have multiple IT staff, they can update the documentation as needed, and since a history is kept, you can see the changes and who made them.

All in all, a very useful tool.

So, Juliet suggest mediawiki, which is very similar to the old wikipedia layout. Mediawiki requires a database backend (the usual suspects) PHP5, and a webserver (supported is IIS, Apache). I decided to try an install on 10.4.11 server, as I'd recently acquired a couple of cheap 10.4 licences, and 10.5/10.6 Server have their own wiki services built in.

First up was setting up a virtualised Mac OS X Server. More challenging than it appears. First attempt was with VMware Fusion 3. I used the 10.5 profile, and installed from a 10.4.7 iso. Install went ok, config went ok, update to 10.4.11 et al went ok. Open a terminal and type mysql -V and the VM hang. Interesting, reboot and try again. Same thing. Re-install to 10.4.7 and same thing, update to 10.4.11 et al and same thing.

So, no luck with vmware. I decided to cut my losses and try VirtualBox.

VirtualBox is maybe not as nice, but is a little more 'flexible'. So, go through the install routine under VirtualBox, and config, and update, and test and it works.

Now, 10.4.11 comes with PHP 4.4.9, so to run the current release of MediaWiki, I will need to update to PHP5, with the appropriate mods for Apache 1.3 (or else also update Apache to Apache2 on Tiger). Luckily, the guys at entropy.ch have already built PHP 5 for Mac OS X. But on 10.4.11, only version 5.2. But it will work, so I download, and install, and follow the instructions to disable the php4 module for Apache in Server Admin Web service.

Restart the web service, make a test page index.php with a print statement and the phpinfo() function and confirm that PHP5 is installed and working.

The next step is MySQL. The tools for starting/configuring MySQL are in /Applications/Server in 10.4. It's nice that they decided to integrate it into Server Admin in 10.5. I start the service, and set a mysql root password.

Good to go? Not quite. The PHP5 module references the default socket for mysql, which is /tmp/mysql.sock, rather than /var/mysql/mysql.sock. This need to be changed in the php.ini file, which is in a different location since PHP5 has installed into /usr/bin/local rather than overwrite PHP4. Which is a good thing, just takes a little hunting around to find it.

I updated the php.ini file, restarted apache, and checked my test php page to see if it the updated mysql socket details have come across.

Everything is ok, so I download and extract the mediawiki tarball, and set up a website to point at it, and create and chmod a config folder. And run through the install. No issues. Copy the created conf file to the web root, and we're up and running.

It works.

Is it worth it? Or is 10.5/10.6 wiki easier to deal with? It's a little bit of work, and I'd only recommend it if you needed to run it on 10.4. If you have 10.5/10.6, then it is far less effort to install (enable php5 module, start mysql, set up a website to point at the extracted mediawiki folder), although still a little more effort than setting up the wiki service. The 10.5/10.6 wiki is better looking by default.

Assuming you were installing this on a hosted service, with only FTP and phpMyAdmin (and php5/apache etc), then it is very doable. All files can be uploaded, moved, created, manipulated with any decent ftp client, and phpMyAdmin will allow you to manually create the databases if you don't have the mysql root password.

One of the things this experience does underline, though, is some of OS X's weakness compared to Linux. Installing an updated version of PHP on any major distro of Linux, is near trivial. Indeed, updating Apache and MySQL is fairly trivial, too. If I had wanted or needed the current version of PHP (5.3.5), then I would have had to build from source, which would mean digging around for the source and instructions. Macports does have 5.3.5, although it is not clear if it apache2 only.

Permalink

Another RAID failure

03/02/11 | by admin [mail] | Categories: Hardware

Actually, this is two stories. A client had a mirror RAID die on them about 4 months ago, but could not be convinced to spend the money on a second drive (about $100) to replace the failed drive and rebuild the mirror. So, 4 months later the other drive failed. And they had to pay for 2 hours labour to recover the data, luckily they had a relatively current Time Machine backup. And they were down for days.

This underlines the earlier point that similar drives have similar failure rates. If you build a RAID with identical drives, expect the 2nd drive to failure not long after the first, and if you build a RAID-5 with identical drives, you are asking for trouble.

The second story is about an external RAID-5 box. A couple of clients have had these. They are a nice idea. An external device that does RAID 5, and connects to the host with eSATA, USB, Firewire etc, and does all the building itself. What they offer is a self contained and reliable storage. However, my experience with these devices is that they aren't quite reliable enough. In one instance there was a brief power outage causing the RAID box to report itself as failed (the server etc came back up without issue). It necessitated an onsite, and re-reading the config from the drives. In the second case, the RAID box was powered down over the christmas break, and on restart reported itself as faulty, necessitating an onsite and same procedure of re-reading the config from the drive.

This RAID box failed at the core task of a RAID, reliability and continuity. In both cases, no data was lost, but time was lost. If the device fails at one of its core duties, it fails as a product.

Permalink

Xserve discontinued.

20/01/11 | by admin [mail] | Categories: Hardware, Mac

Apple has decided to discontinue the Xserve. They say because it was a money losing product. They are offering Mac Pros with OS X Server and Mac Minis with OS X Server as alternatives.

I'm not sure what to make of the decision to discontinue the Xserve. The Xserve was a real server product, with a 1U form factor and redundant components, built for the enterprise and datacentre. If you are looking for a Mac Server for uptime critical applications, there is no alternative. If you need 1U formfactor computers for collocation, then you can try the Mac Mini and hope they don't fail too often.

Certainly, for smaller workgroups (design departments within enterprises, or small to medium business), the Mac Mini or Mac Pro are real alternatives.

The Mac Pro is more expandable, and can be connected to a Promise RAID, SAN or other Fibre Channel or eSATA devices, but it is a whopping 7U of space. If you are paying by RU (as is usual in most collocations) then this will cost considerably more. If you are interested in HPC or clusters, then you might need a little more room (although the Mac Pro does have superior cooling, so you might save some space there).

The Mac Mini Server is good for smaller tasks, we have installed them in offices of 10 users, and as single service devices (mail services). However, with their lack of expansion and Core 2 Duo processors, they aren't much use where you need lots of storage or lots of power. They aren't too good for running virtual machines, for instance.

Neither the Mac Mini nor the Mac Pro offer redundant power supplies. You can use a UPS, but the power supply in the computer will still be a single point of failure. This means downtime.

Neither the Mac Mini nor the Mac Pro offer hot swappable storage. This means downtime.

Apart from the technical, the other thing dropping the Xserve does is send a message that Apple is no longer interested in the enterprise, indeed is not interested in the clusters used for video production and CGI. The question remains whether Apple will continue to ship its server software and XSAN. If Apple is moving away from the enterprise, should the enterprise be moving away from Apple?

Permalink

Mac OS X 10.6.6

10/01/11 | by admin [mail] | Categories: Hardware, Software, Mac, OSX

So Apple decided to release 10.6.6 the day after I installed my CalDigit USB 3 card. This is an issue because USB 3 is very new, and the drivers (kexts) are still not completely solid. CalDigit released an updated version of their driver for 10.6.5 (and make you jump through some hoops to get it), since the driver broke with the 10.6.5 update. Their current (10 Jan) recommendation is not to update to 10.6.6 until they have done their tests (and probably released a new driver). Update: a new driver is available.

So, the Mac Pro is on 10.6.5 for the meantime, but the Mac Mini is on 10.6.6. I've tried out the app store on the Mac Mini and downloaded an app. The nice thing is it is a little easier to search and find stuff than apple.com/downloads. The downside is that it requires 10.6.6, many of the apps cost money (interestingly the AUD prices are STILL much higher than the USD equivalents despite the exchange rates). And the fact that Apple can now easily track what you download and where you install based on your AppStore account.

The good news is that you can copy some apps from the Mac where they were downloaded to another Mac without issues. So, set up a Mac with the account, and then copy the apps (many ways to do this) to however many other Macs you like.

Permalink

Debian on a Via Epia

10/01/11 | by admin [mail] | Categories: Hardware, Software, Linux

I mentioned that I also installed Debian on a Mini-ITX box, specifically it is a VIA Epia with a 533MHz Eden CPU, and nearly all you need integrated (as mini-itx boards normally are). I bought it a little while ago from someone who had assembled 95% of the parts to make an ADSL/WiFi router, but gave up on it. All it needed was a case/psu, which cost about as much as the board and bits I had already purchased. The other small problem was that it only had 256MB RAM. Not really enough. But since I had just upgraded the Cube, I took the two spare 256MB chips and bumped the RAM up in the MiniITX to 512MB.

I had previously attempted to install 3 or 4 distros (Fedora, SUSE, Mandriva etc) on this box, but had a variety of issues, ranging from the installer not running (or halting part way through), installing but then going into a restart loop, or installing and then not doing anything. This is probably due to the fact I was using current distros on a rather old board. So, back to old faithful Debian, which goes out of its way to support obsolete hardware like this.

I used a 5.0.4 DVD to install and only two little snags during the install: the Intel wireless card needed nonfree firmware (very simple to do), and half way through the pre-install config, the font died and turned to the default square boxes for all chars. Fortunately, I found screen shots of the install online and could work my way through the rest of the config. Installed ok.

At some point I will need to configure the WiFi on the MiniITX box, and put it in an appropriate location. I'm thinking to play around with kismet.

Permalink

A typical weekend

10/01/11 | by admin [mail] | Categories: Hardware, Software, Networking, Mac, OSX

So, this weekend I did the usual housework, eating, sleeping, watching TV etc, that people the world over do of a weekend. The other thing I did was install Debian on a mini-ITX system, and Mac OS X Leopard on a PowerMac G4 Cube.

The Cube is a little upgraded, having an 80GB hard drive, 1.5GB RAM (a Friday night upgrade after ordering 2x 512MB sticks from OWC), Airport, nVidia 6200, and a Sonnet 1.2GHz G4. Since the CPU is upgraded, Leopard will install without issues (it has a 867MHz G4 minimum requirement, although trivial to get around). I did the install using Netboot from a virtualized 10.5 server (another weekend project). I created the boot image from a 10.5.4 ISO image, which was mounted to the VM (Fusion) using the virtual optical drive device.

Boot over the network from the image, and then upgrade the installed 10.4.11 Server (this Cube was set up briefly as a server). There were, needless to say, a couple of hitches. I could not remember the original password for the admin account (I had to reset it last time, as well), so I needed to reset the password using the install disk, which did not work. So, retry to make sure I had clicked all the right buttons etc, and still no go, so a boot to single user mode to edit the local directory using dscl.

Dscl showed that the user accounts had not been imported. The home folders were there, but no account entries in the local node. So, reset the root password, reboot, login and then re-created the account. dsenableroot is a nice trick,

The other, small, issue was that the Airport card could not connect to my draft N WiFi (airport express). Not a big deal since 10/100 Ethernet is working, and I can always plugin in an older basestation (WAP) if needed.

Next trick is to get an SSD drive to saturate that slow 66mbyte ATA bus :)

Permalink

Mac Myths

09/01/11 | by admin [mail] | Categories: Hardware, Software, Mac, OSX

Working in the Mac world, I sometimes forget how little non-Mac people know about Macs. Even people in IT are surprised to know that Mac OS X Server even exists.

So, there are a few interesting factoids I'd like to share.

Mac OS X is Unix.

To qualify that a little, Mac OS X 10.5 and 10.6 running on Intel Macs is qualified as Unix by the Open Group, the only BSD variant qualified as UNIX03.

This means that Mac OS X is probably the most widely used UNIX in the world. The current Mac userbase is between 30 and 94 million (and the vast majority of these are running 10.5 or higher on Intel Macs). This leads to some interesting conclusions. AFP is probably the most widely used UNIX network file system. HFS+ is probably the most widely used UNIX filesystem.

Mac vs Linux as desktop *Nix.

Estimates of the Linux user-base put it at about 30 million. Mac OS X undoubtedly outnumbers Linux on the desktop, but Linux is still ahead in the server market and probably ahead in the embedded-device/appliance market (despite the success of IOS on iPods, iPads and iPhones).

Macs have Unix tools

There are about 12000 Linux/Unix ports available via Fink. Mac Ports has about 5400. There is some overlap between the two. This compares with about 24000 in Debian.

Mac OS X comes with a large array of standard UNIX tools and FOSS. Mac OS X (the standard version, not the server), comes with bash, tcsh, ksh, ssh, telnet, vnc, ftp, Apache, PHP, Python, BIND, Perl, Ruby, Rails, Kerberos, Postfix, Dovecot, AMaViS, RADIUS, Samba, NFS, X11, gcc, curl, rsync, dtrace, OpenLDAP….

…and CUPS, which is now owned and maintained by Apple, and more.

Macs run Linux.

Linux was first ported to the Mac back in 1997. Debian for PPC Macs was released in 2000. Ports also exist for 68k Macs, and Nubus PPC macs (the first Power Macintosh x100 series). Linux for the PowerPC was first released at the 2.2.x version of the kernel. Current Macs will happily dual (or multi) boot Linux, or run Linux virtualised. It's also possible to run Linux on a Mac, run Mac OS X virtualised under Linux.

Macs have malware.

Malware exists on the Mac. The largest class by numbers is still Office macro viruses. There is a growing number of Trojans (distributed mainly in warez), and web browser (java/flash etc) based malware. The Mac is probably also vulnerable to other application based exploits, like the famous PDF exploit.

Macs also have security software.

Mac OS X has a firewall. Free anti virus is available in the form of clamav, and the frontend ClamXAV. And has been available for many years. Mac OS X Server ships with clamav antivirus since at least 10.3 (don't ask me about 10.2 server, it's too old!).

Macs have multi-button mice

It is a surprisingly common view, that Macs only have single button mice. Multi-button mice have been available for Mac users for 20 odd years. Native support for 2+ buttons and scroll wheels has always been a feature of Mac OS X. I've always used 2 button + scroll wheel mice with my Macs, except for my PowerBook G3 (since it had a built in trackpad). All currently shipping Macs feature multi-'button' and scrolling support, and have done for more than 5 years.

Mac OS X is open

This is an interesting situation. Mac hardware is closed to an extent, and the OS is only designed and licensed to run on Apple hardware. But Mac OS X is Unix, and Unix is a fairly open platform in any flavour. You can install whatever you like, compile what you like, modify and customise a hell of a lot. Nearly all preference/configuration files are in text, or easily convertible to text, and XML formatted. Some of the OS is opensource, although covered by licenses of varying restriction.

The basic BSD framework underlying the OS is called Darwin. The sourcecode is open to read and compile, and to some extent to modify/distribute. Different parts are covered by different licences. Most of the Apple developed components are covered by Apple Public Source License. Apple were releasing ready to install binaries up until Darwin 8 (10.4), but stopped due to limited interest. You can get ready run installs of the Darwin based GNU-Darwin.

Apple developed launchd to replace init/xinit. Basically, launchd is a daemon which starts other daemonised services and agents, both system and user. Originally, it was released under Apple Public Source License, and there was some interest from people such as Ubuntu, however the licence was determined to be too restrictive. Apple has since changed the licence to the Apache License v2 to encourage broader adoption. And, as mentioned, there is CUPS.

Mac OS X and SOE

An interesting feature of Mac OS X, and this comes out of having well defined hardware it runs on, is that you can take a hard drive out of one Mac, and put it in another and it will work (if the computer you are swapping it to meets the minimum system requirements for the OS). There can be some licensing issues with third party software, but by and large it's plug and play. What this means is that half of your SOE is done for you. The OS and drivers is consistent across platforms (different drivers will be used depending on the hardware, but all the drivers are installed and available).

It makes migration a breeze. On top of this, Users accounts are clearly defined. All the users individual settings are in their home folder, a single directory tree, which can be copied between computers and then associated with a log on account. This means you can do cool stuff like keep user accounts on external media, or on a server, and move them between computers.

So you can adopt a fairly radically different approach to SOE builds. All you need to manage is the third party software, which you can do in a variety of ways. You can develop work flows which build an image for deployment, or update a live machine with the software and configuration it needs. You don't need adopt the more conventional approach of identical hardware, single images with OS and sofware which need to be imaged to the hard drive prior to deployment, and centralised, network based, accounts (and all the required hardware to back it up).

Permalink

Current Hardware Projects

This is all about my on going fumblings with hardware. Regular entries should provide an indication of the depths of my obsession.

2011
 << Current>>
Jan Feb Mar Apr
May Jun Jul Aug
Sep Oct Nov Dec

Categories

Linkblog

Amiga Links

XML Feeds

What is RSS?

powered by b2evolution free blog software