Building a SAN with OpenSolaris and ZFS

The one line summary: OpenSolaris and ZFS is very, very cool.

Having created a ZFS pool "datapool" consisting of two 500GB disks in a RAID1 mirror, I then created a few filesystems, including datapool/filestore which was to be the new fileserver. The whole process took two commands:

# zpool create datapool mirror c3d1 c4d1
# zfs create datapool/filestore

To make the new filesystem available over NFS to my Linux machine took another command:

# zfs set sharenfs=rw,anon=0 datapool/filestore

Okay, but what about the Windows box that doesn't support NFS natively? For this, I had to install the SMB server package (along with the kernel extension) and reboot the server. But after that it was simply a case of one more command:

# zfs set sharesmb=on datapool/filestore

The Mac has a very nifty backup tool called Time Machine. To use it you must directly attach a second hard disk, or tweak the configuration to allow for "unsupported" devices to work. I wanted to add in another hard disk to allow me to run Time Machine. Again, OpenSolaris/ZFS to the rescue.

I installed the iSCSI target server software (a couple of ticks in the package manager) and then ran the following commands:

# zfs create -s -V 100GB datapool/mac_backup
# zfs set shareiscsi=on datapool/mac_backup
# iscsitadm list target

The first command creates a "zvol" - a block device that is built from the zpool but does not have ZFS on it. The -s creates a sparse volume so that the space is not-preallocated. The second command makes the volume available over iSCSI, while the third command lists the available iSCSI targets so you can easily get the iSCSI address.

I then downloaded and installed the free globalSAN software for the Mac which provides an iSCSI initiator. Five minutes later (including a reboot of the Mac because it's another kernel extension), I had a new block device ready for partitioning in the Disk Utility. I created a Mac HFS journaled filesystem which Time Machine is able to use.

So one server can now provide simulateous NFS, CIFS/SMB and iSCSI to all my servers. It really is a small SAN at home!

OpenSolaris, Courier IMAP and FAM

I started the final part of migrating to the new OpenSolaris server today: Moving the internal IMAP server.

This server exists to collect email that is sent to my old address, T's old Hotmail emails (slurped down using a Thunderbird webmail extension and imported into IMAP), as well as act as an archive of all my old email dating back a number of years.

The new mail server will be a Solaris zone called "mailserver" on the OpenSolaris host. I built the zone and installed Fetchmail (to collect mail from my ISP using POP3), Procmail (to filter the email into the correct mailboxes) and Courier IMAP (to serve the email internally over IMAP).

Once I got Courier IMAP installed, and the config file copied across, I hit a problem:

Dec 24 19:19:32 mailserver imapd: [ID 702911 mail.error] Error: I/O error
Dec 24 19:19:32 mailserver imapd: [ID 702911 mail.error] Check for proper operation and configuration
Dec 24 19:19:32 mailserver imapd: [ID 702911 mail.error] of the File Access Monitor daemon (famd).

Hmm, so I need to install FAM. I did the install, but this still didn't work. Turns out that the FAM package doesn't make the necessary additions to /etc/rpc (FAM is controlled by rpcbind) and /etc/inetd.conf.

For reference, this is what needs to go in /etc/rpc:

sgi_fam 391002

And this is what needs to go in /etc/inetd.conf:

sgi_fam/1-2 stream rpc/tcp wait root /opt/csw/bin/fam fam

To register the inetd config, the inetconv command needs to be run at which point, starting Courier IMAP works and the above error has gone.

Job done!

New kit, new project, new stuff to learn

Although I bought the ML110 G5 a few months ago, I have only been using it as a "play" machine. Earlier this month, Ebuyer got the ML115 G5 back in stock, so I took the opportunity to snap up one of those, along with 2 x 500GB disks, a 4GB RAM upgrade, 8 port Gigabit switch and a 4GB USB key drive.

You see, this is the plan:

The ML110 G5 will be the "production" server, running OpenSolaris 2008.11and playing the role of a storage server along with some core infrastructure services. I took the 250GB disk out of the ML115 and put it in the ML110 and mirrored the existing 250GB disk. I also added the 2 500GB disks in a mirrored pool. All of this is using ZFS for resilience and only takes a handful of commands to setup.

The OpenSolaris server is now running my print server software (CUPS) and works with the Linux machines, the Mac and even T's Vista PC. I'm running a small BIND DNS server for keeping track of the internal machines, and have a number of NFS shares setup for file serving, an ISO store and (in the near future), a VM datastore. The beauty of ZFS is that in addition to serving filesystems using NFS (and CIFS using the new kernel based service), other filesystems can use the ZFS technology thanks to zvols (essentially block devices in a zpool that can be shared using iSCSI and FC).

The 4GB USB key drive has VMware ESXi installed on it and the ML115 boots this. The USB port is internal, on the motherboard, so everything is nicely integrated. The actual VMs will be on the storage server - initially using NFS, but potentially using iSCSI in the next OpenSolaris release as well. Sounds like a SAN at home? Yep! :-) (this is why I've upgraded the switch to gigabit).

One of the things I'm finding with OpenSolaris is that although I've been using Solaris for years, there are a lot of changes (that presumably will make it into Solaris 11). The biggest one I've hit so far is the Image Packaging System (IPS). This appears to use a network repository for installing software (so no local .pkg files) and creates some new differences with Zones (they are now branded as "ipkg" and I think I've lost the ability to create sparse root zones in this release).

Still a lot to do and play with, but OpenSolaris certainly seems very feature-rich, and nothing else currently provides stuff like ZFS.

I might even have a look at getting xVM installed as well, but that might take a bit longer...

Vista PDF printing problem

T has a problem printing PDF files from her Vista PC. The print server is a Solaris VM running CUPS and all other documents seem to print without any issues. It appears that selecting Print from the Adobe Acrobat Reader application doesn't send anything to the print queue.

The reason I'm blogging about this is the result of T noticing that she never gets a mention and therefore "Why don't you blog about it and see if anyone knows the answer".

What is this? A Helpdesk? :-)

iMovie 08 - the good and the bad

I'm working on a 5 week project for church where we are recording a 25-35 minute teaching sermon per week for the purpose of creating a DVD resource. We have three cameras that are mixed by a Datavideo SE-500 video mixer. This outputs to a DVD-RAM recorder with a separate hard disk recorder for backup.

As we shoot and mix the whole thing live, I've been editing minor glitches in iMovie 08. This is the workflow:

1) Insert DVD-RAM disc in the Mac Mini and copy the VR_MOVIE.VRO file onto the disk.
2) Copy this across to my Linux workstation and re-encode it into DV using ffmpeg-kino.
3) Import the resulting (large) DV file into iMovie.

This works very well and I've been able to edit out the odd glitch very quickly. A minor error (where the speaker then repeats the offending line) can be tidied up in about 2 minutes. It's been taking me no more than 15 minutes to edit the source video. This is the good.

The bad occurs when I want to insert graphic shots from PowerPoint over the video (without interrupting the audio). To do this, import the graphics into iPhoto and then in iMovie, drag and drop the graphic over the video and set the duration. iMovie will then create a smooth cross fade into the graphic and back while the audio continues.

Very smooth.

Until you want to put more than about three graphics into the movie in this way. At this point, the live preview stops working (so you can't skim over the video and see the transition render). It gets worse when I export the "completed" video file; the inserted graphics are rendered in and fade correctly, but the order of the graphics is messed up.

I've tried to split the source video into smaller clips but this has not helped. I've logged it as a bug with Apple, but iMovie is too buggy to use for anything beyond basic clip editing in its current state. Shame really as when it works, it works very well. Apple - please fix!

Google Calendar Sync not synching... the fix!

A while back I noticed that Google Calendar Sync was not correctly synchronising all my calendar entries. While some were okay, others refused to appear. Having spent a couple of hours last night working on it, I have found what I believe to the be the solution.

The problem was either me being too clever, or Google Calendar Sync not being clever enough.

Back when I started using Outlook as my main calendar, I wanted to prevent my work colleagues from viewing my personal appointments. The easiest way to do this was by setting all appointments to be private by default, and then change them if it was a business item. This involved editing the appointment form in the Outlook designer and saving it as a new form (that I called "Private Appointment".

Unfortunately, Google Calendar Sync only tries to synchronise calendar items that are Meetings or Appointments. My custom form was not being synchronised. I've now changed the default form back, but will need to find a way to convert all my private appointments into "normal" appointments.

Once I knew what the problem was, I was able to Google and find that numerous people have had similar problems when they've installed an Outlook add-on such as WebEx or integration with Live Maps.

Now I know this, hopefully I'll be able to get my calendar working properly again and join it up with the rest of my cloud activities.

Moving VMs from local disk to shared storage

We've had VMware Infrastructure 3 for over a year, but our usage of it has been "organic" (read: unplanned and unstructured). Yesterday I started making moves to rectify that.

One of the things we didn't get right at the start was setting up the SAN to store all VMs. This resulted in a number of VMs crammed onto internal storage. Some VMs were loaded on SAN LUNs, but we didn't have the LUN mappings setup to allow multiple ESX servers to see them.

As I said, it was an organic install.

So yesterday I created a new 250GB LUN on the SAN and mapped it to our "infrastructure" ESX servers (three HP DL360 G4 servers - not super fast, but sufficient for domain controllers etc.). For the first time, multiple ESX servers could see the same storage.

My first action was to create a small Linux server on the shared storage and test Vmotion. This worked fine, so I started copying the VMs from internal storage to the shared LUN. To do this, I shutdown the VM, browsed to the VM folder in the datastore browser, highlighted it and selected "Move to..." from the context sensitive menu. I then selected the new SAN LUN and started the move.

Once moved, the VMX file needs to have the execute bit set (using chmod from the ESX service console), and I then removed the VM from the Virtual Center inventory. I then re-added the VM by right-clicking the VMX file in the datastore browser and selecting "Add to inventory".

Upon starting the VM, a question needs to be answered (the icon for the VM changes to a speech bubble - right click and select Answer Question). Because the VM has been moved, elect to "Keep" the VM id. The VM will then fire up properly.

Or it did in most cases. One VM gave an error that it was "Unable to lock file". A quick Google suggested a LCK file, but I didn't have one of those. To resolve this problem, I edited the VM settings and removed the hard disk (from the VM, NOT the disk file!). I then re-added the same disk, and the VM started without problems.

Migration to Google Mail

Although I've had a Google Mail account for a few years, I've really only used it as a test account, or when I've not had access to my personal email. Instead, my main (church) email address has been accessed by Thunderbird on my local machine. Obviously this is not ideal from a cloud computing perspective.

So tonight I took the step of migrating all my email from Thunderbird to Google. I did this using the IMAP interface to Gmail and dragging and dropping messages up to the cloud.

In order to ensure that all new messages go to Google, I configured Gmail to download my email using POP. I've also got the webmaster account on a Google Apps domain for a local charity, which I've now changed to forward to Gmail.

The net result was an inbox with > 1700 messages and taking 325MB (out of a quota of 7178MB).

The next step was to use the Gmail filter capabilities to add tags for my emails based on destination email address. Once this was done, I spent a couple of minutes archiving all email older than 1 month.

Now I have a tidy inbox, accessible from everywhere I can use a browser, collecting email from three different addresses and automatically tagging incoming messages.

VMware ESXi on an HP ML110 G5

I recently bought an HP ML110 G5 from Ebuyer because it was going very cheap (£220 for a dual core Xeon, 1GB RAM and 250GB hard disk). This box will be my new server, possibly for trying things out with, but maybe as a replacement for my Shuttle that currently runs VMware Server on OpenSUSE.

Unfortunately, the first attempt at installing ESXi failed with the message that no storage devices could be found. After some searching, I found that by changing the disk settings in the BIOS from "Auto" to "SATA" fixed the problem and the disk was found (full details here.

The installer again failed with the following error: "Unable to write image to the selected disk. This maybe caused by bad sectors on the device or another hardware problem."

One comment I read suggested the amount of memory could be a problem. As this is to be a VM server, I ordered another 4GB RAM (CT810056 4GB kit (2GBx2), 240-pin DIMM Upgrade for a HP - Compaq ProLiant ML110 G5 System) from Crucial and fitted it this morning.

ESXi installed without any problems. Now to install some VMs...

The essential Windows setup

Although my home environment has only a single Windows machine (T's desktop), I occasionally get involved in the support of other people's PCs and laptops. Over the time, the list of things that I do on these machines has evolved. This is what I do with new PCs (August 2008 edition :-))

Get a broadband router

I always recommend a router instead of an ADSL modem. This provides the security of a hardware firewall as well as the ability to have multiple machines connecting and wireless access. My preferred model is the Netgear DG834G which fulfills all the requirements. I'm sure there are equally good models out there, but this is cheap and works reliably. It's the model we recommend for our users at work and it's the same model I've deployed to almost all my users.

Operating System choices

Despite the fact that Vista has been given a battering for being resource intensive, with enough memory (2GB minimum), it can do a pretty decent job for the average user. I always make sure the machine can handle Aero Glass (if it can't, then it's too underspec to consider).

I'd like to be able to recommend a Mac or Linux, but for most of my users, it's easier to go the Vista route.


Remove the bloat

The first step is to remove the "value add" software and trial software. First culprit is usually the evil Norton Internet Security. By removing these unasked for applications, and tidying up the URL shortcuts to various ISPs, Ebay etc. can speed the boot time up considerably.

Create a rescue CD

If the machine does not come with OS media or a "Recovery Disc", it is essential to create one. This usually involves the creation of a set of disks that copy the data on a resuce partition to DVD. Keep these safe in case the hard drive dies.

Fix the default IE page

Set it to about:blank and not the advert infested mess that the manufacturer points you to. It's worth doing for those rare times when IE is a necessity.

Install Firefox

Although IE7 was an improvement over IE6, Firefox is my favoured browser and one I recommend to all my users. This typically requires the additional download of the Flash plugin afterwards in order to allow access to YouTube etc.

Install some Anti-Virus Software

I used to recommend the free version of AVG, but found recently that Microsoft OneCare is pretty decent for the price. It's fairly unintrusive and can be installed on several machines using the same licence. It's since become my recommended AV solution and the one that I have been installing on my users' machines.

Recommend an external hard drive

I'll always recommend an external hard drive for users to backup their data. People often put so much data onto their machines that it's folly not to have some form of backup. Then it's a matter of configuring the backup to run(!), using either the Vista backup or letting OneCare handle it.

Limited user rights

This can be tricky to deploy and depends largely on the needs of the users, but if possible configure the main login to be a normal, non-administrative user. This can drastically reduce the amount of spyware that gets on the machine. (This doesn't always work as the daughter of one family managed to guess the admin password and escalated herself to an administrator. She then proceeded to download all sorts of malware).

Remote Admin

I only do this on a few machines, and always with the consent of the owner. An install of VNC running as a service, and the appropriate firewall forwarding rule has allowed me to manage some machines remotely (mostly family). This often requires the router to be configured to use dyndns.org (which the Netgear does) so I can connect via hostname, even when their ISP uses DHCP.

Summary

Although there is nothing here that is rocket science, the result is a nice, quickly booting machine that isn't loaded up with crap and is a nice setup for most users.

The iPhone 3G: First Impressions

After a 50 minute queue at the local O2 store, and the problems of actually getting an activated iPhone, I managed to walk away with on Friday, and after a busy 24 hours, I've finally got around to setting it up and having a play.

First impressions?

This is completely unlike any mobile phone I have ever used. The iPhone is awesome!

What's there to like?

1) I can access all my mail accounts - personal IMAP server, Google Mail and Yahoo Mail.
2) Safari is completely usable and supports multiple pages being active - a real "wow" moment when I found this.
3) It has picked up my iCal calendars, including my Google Calendars.
4) The Maps GPS location is very cool.
5) The App Store makes adding applications a breeze. So far, I've only tried one (the Bible), but will have a proper hunt later
6) Predictive text with spell correction is very cool and I'm starting to get used to the virtual keyboard.

No negatives yet (although I'm sure there will be some).

Summary: Best. Phone. Ever.

Is OneNote a Cul de Sac?

There has been a lot of buzz around the office recently about Microsoft OneNote 2007. For the uninitiated, this application is basically a collection of notebooks for jotting down information. Notebooks (e.g., Work, Personal) have sections (imagine dividers in a traditional notebook) which contain pages. It's possible to create free form text, drag and drop image, links etc.

All in all, a very nice application that I'm looking forward to getting stuck in with.

My only reservation is that it uses a proprietary file format to store the notebooks, and it appears to be very single-user focused. There are ways of sharing notebooks, but these seem to be limited to placing them on file shares.

In some ways, it's a bit like SharePoint - easy to setup and load stuff into, but more difficult to untangle yourself from should you decide to migrate away from Microsoft. Perhaps that's the plan...

Zoho has a Notebook application on the cloud which is very advanced, but I'd be more reluctant to trust a small company with my data than managing it myself.

If only someone could come up with an application that does everything OneNote can do, but in a true client/server model, with offline capabilities, web access, and an open source licence. Any takers?

A week of interesting technology

Last week I had the opportunity to use a number of interesting technologies and applications. I've already blogged about the Cisco Network Assistant, but that was only the beginning.

We were running a VMware Server virtual machine that was not performing correctly. The physical hardware was not up to the job, so we wanted to migrate the VM to our ESX server. The VM was configured to use a virtual IDE disk which prevented us from importing it directly into ESX. Enter VMware Converter. This piece of software allowed us to step through a wizard where we selected the source VM files, and then entered the server name we wanted to save the machine. A few other options later (selecting the destination datastore and similar), and the conversion process started. Twenty five minutes later it was all done. The converted VM had been streamed into place and was ready to go. Really simple and worked first time. I was impressed!

The end of the week gave me the opportunity to experiment with Sun Logical Domains (LDOMs). This hypervisor based VM technology can be found on the Coolthreads range (using the new sun4v architecture). Unlike Containers, LDOMs allow different Solaris versions to be installed. We're testing the performance of the machine to run as an Ingres server, so I'll most probably update the blog later this week with more information.

This week looks equally promising - Apple's WWDC was yesterday, although I haven't watched the keynote yet. The 3G iPhone isn't unexpected, but is now quite tempting, even with a £35/month contract as I can't think of a better mobile web browsing device. And then there is the announcement of "MobileMe" (aka, "Exchange for the rest of us"). It's certainly something to look into to...

A day with Cisco Network Assistant

Today I spent a significant amount of time using the freely available Cisco Network Assistant. This tool allows you to probe your [Cisco] LAN and identify the topology. This proved very useful as although I had a rough idea of how the network was wired, the software highlighted a couple of issues that I need to resolve. Once identified, you can directly interact with the devices, renaming switches, creating VLANs, enabling and disabling ports. Really, really nice - especially for the price.

The reason I'm doing this is that I want to get the topology accurately mapped before starting my Nagios deployment for network monitoring.

The only downside was discovering the SFP modules we bought for server interlinking were not "Cisco Compatible", so we'll have to spend double to get the same thing!

Sun Certified System Administrator

Today I took the Sun Certified System Administrator for the Solaris 10 Operating System Upgrade Exam (snappy title huh?). I passed - but only just.

To aid me in my revision, I used the "Sun Certified System Administrator for Solaris 10 Study Guide" by Paul Sanghera published by Osborne, and "Exam Prep Solaris 10 System Administration" by Bill Calkins published by Que. This is on top of using Solaris on a daily basis for the last eight years.

After revising from both these books and taking the test questions, I was consistently getting over 80% from both books. Considering the passmark is 60% for the upgrade, it looked pretty good.

So imagine my surprise when I sat down in the exam and was confronted by a number of questions that are not covered in either book! The confidentiality agreement prevents me from detailing too much about the content, but I was also surprised to find that the questions were based on a small subset of topics.

This is apparently because Sun have upgraded the exams earlier this year and the books are not yet updated. Calkins has a update on his website detailing the changes (which I've only just found!).

So beware if you want to revise this certification! It's not a walk in the park and make sure you know your Flash from your Grub...!

Wireless EEE problems

Although I've used the EEE PC on a number of different wireless networks, I could not get it to connect to my Netgear DG834G at home. It would see the network, but would not connect and obtain a DHCP address.

To cut a *very* long story short, the problem was that I had configured access lists on the router so that only specified MAC addresses could connect. This was denying the EEE PC access before it even got as far as authenticating.

I added the EEE to the list of allowed addresses and a minute later was happily connected to the web using WPA encrypted wireless.

Nice.

8bit nostalgia

Over the last few days I've been browsing sites dedicated to the old 8bit BBC micro made by Acorn computers in the 1980s. I was first exposed to the BBC at primary school where I think they had two of them (for the entire school!). When I reached secondary school, I joined the break and lunchtime "Computer Club".

At home we had an Acorn Electron. This was a cut down version of the BBC that ran at a slower speed (1Mhz vs 2Mhz), only a single channel for sound and missed the memory efficient Mode 7 screen mode. This did not deter me from adding a printer, disc drive and some ROM cartridges (for word processing and spreadsheets). My Dad then used the machine to write up notes and sermons.

At school I used the Acorn Archimedes (the first RISC computer available to the masses) but for home use I eventually got a 286 PC and he upgraded to a BBC Master - the pinnacle of BBC 8bit computing.

This would have been in about 1993. So why blog about it now?

I'm realising in my browsing just how well designed the BBC was. No other machine had the potential for expansion or the fantastic BBC BASIC. The implementation of BASIC was beyond all other 8bit micros and had named procedures and an inbuilt assembler. The operating system (16k!) provided access to the hardware in a very simple way.

The BBC could have benefited from some better graphics (say 16 colours at a 320x256?) and a beefed up sound chip (it's not bad, but not as powerful as the SID in the C64), but it remains to this day a classic machine that can stand proudly among its peers.

I must visit my parents and hunt down the BBC Master...

VMware Server Performance Issue

I've been running VMware Server on the SilverShuttle for a while now (140 days and counting!). The little machine is generally running very well with its two VMs - Solaris Nevada and CentOS, but occasionally the machine stutters very badly and the load average within the virtual machines shoot up from the 0.1 they usually are to about 40.0!

Unfortunately, running top and prstat did little to suggest any reason, and the host operating system (SUSE 10.1) didn't seem to be having any problems of its own apart from the VMware processes which were now taking a lot more CPU.

Cutting to the conclusion, after a period of investigating what might be the cause, I turned off the powersaved daemon on the host operating system. Since then, performance has been rosy. I'm guessing the powersaving was kicking it, misreporting the CPU speed to the VMs which were then choking (but it's just a theory).

All is now well.

Installing Alfresco

A week ago I decided to install the Alfresco open source enterprise content management system on my CentOS VM. The basic install is very easy, comprising of creating /opt/alfresco and untarring the downloaded file into it. The demo version uses HSQL as a content repository, but this isn't recommended for production use.

I opted to change the datasource to MySQL and after setting up the database (using the script provided), I had problems starting the Alfresco installation. I then ran out of time and abandoned it.

Today I went back to the install and after doing some reading up, found that the problem was due to changing the content repository from HSQL to MySQL. As I had no content to worry about, I deleted /opt/alfresco and reinstalled. The big difference this time being that I did not start the installation before I changed the settings to MySQL.

And it works! I now need to learn how to use it, but it appears to be a very powerful piece of software. More blogging soon...

Reflections on the Macworld Keynote

I subscribe to the notion that the Macworld Keynote is one of the most important presentations in the IT industry. This is because Apple have a unique ability to create very smart and easy to use products that appeals to non-technical people, while also creating kit that geeks enjoy using (the number of MacBooks being used at the UK Unix User Group was testament to that).

Last year was the iPhone, which although not being a perfect product (lack of 3G for example) has shaken the mobile market so much that every other mobile company is having to up their game. Apple was also a significant influence in leading the music industry to drop DRM.

The buzz at this year's presentation is surrounding the MacBook Air. But in my mind, the biggest news is the upgraded Apple TV. When this was released last year, the Apple TV was pushed as being an iPod for the living room. This year, Steve Jobs admitted that the product didn't meet expectations, but they were revisiting it. The big news was the introduction of movie rentals.

iTunes Movie Rentals provides a way to download movies from iTunes straight from the TV with no computer being required. These movies can then be saved for 30 days and once started, you can play it for 24 hours. If this works for rentals, then presumably the next step would be purchases over the Internet. This could make the HD-DVD vs BluRay conflict completely irrelevant. The number of Playstation 3s will ensure that BluRay has some future, but perhaps the convenience of online purchase of movies will mean BluRay won't automatically replace DVD as the de facto format.

Regarding the MacBook Air - it really is thin and the multitouch demo was very impressive. It's not something I'd be interested in getting, but I can appreciate there will be a lot of people who will want one.

So although this year there was nothing to top last year's iPhone announcement, the potential for the upgraded Apple TV could be as disruptive to the media world as the iPhone has been to the mobile phone industry. Let's see how everyone else responds...

Updating the backup process

When I upgraded from OpenSUSE 10.1 to 10.3, I took the decision to migrate away from XFS and use EXT3. Although XFS had served me well for many years, I felt the simplicity of using the "standard" Linux filesystem would make restores easier. For large filesystems with high throughput, XFS is fantastic, but for more home workstation, I don't think there is much in it. Actually, if anything, EXT3 is more responsive when doing a backup.

In making the change, I had to modify my backup scripts to use ext3 dump instead of xfsdump. This gave me the chance to revisit the LVM snapshot section I wrote a few years ago, but could not get working with the kernel supplied with 10.1 (It worked. Sometimes).

The new script is very simple and does the following:

1) Takes a filesystem to dump and dump level to take (0 = full, 1=everything that has changed since the last level 0, 2=everything that has changed since the last level 1 etc.).
2) Works out the underlying LVM logical volume the filesystem is built on.
3) Creates a snapshot of the logical volume and mounts in under /snapshot
4) Performs a dump of /snapshot to my external (Firewire) hard disk.
5) Umounts /snapshot and destroys the snapshot.

It appears to be working pretty well and provides what should be a very simple mechanism for ensuring my main workstation is backed up.

T's Vista PC is backed up to another external Firewire hard disk using the built in Vista tools. This appears to do the job and happens automatically, so it's a fire-and-forget operation.

I'm not currently backing up the Mac. This shouldn't be a problem because all my important files are stored on the network. It also seems that Time Machine has some limitations (setting backup schedules, limited to using local storage etc.). I'm guessing a future version of Mac OS X will fully support ZFS and will use ZFS snapshots for backing up.

This leaves the "SilverShuttle" which is my VMware Server / Solaris server. This needs some form of backup and I'm still chewing over the options. I'd ideally like a large external array with a bunch of disks that are managed by ZFS, but this doesn't solve my desire to keep an off-site copy of my data. Something for me to work on then...

A solution to wireless hassles: Ethernet over mains

I have all my computers upstairs in our office (second bedroom), but the telephone enters the house downstairs in the lounge. For the last few years, I've put the ADSL router (Netgear 834G) in the corner and connected to the upstairs using a Wireless Ethernet Bridge (Netgear WGE101). This worked pretty well at first - until I started getting neighbours with wireless!

I first realised that those around me were getting wireless connections when my own LAN kept losing the router. This was quickly fixed by me changing my channel to something unused, but random connection problems still persisted.

The other night I stared in bemusement as the Wireless Bridge claimed a 99% signal strength to the access point on my router, but refused to connect. I remembered a conversation I had with a colleague a few weeks previous where he mentioned that he had installed Ethernet over mains power.

So after T finished watching an episode of Desperate Housewives, I flicked the switch in the fuse box labelled "sockets" and observed that all mains sockets went out - both downstairs and upstairs - indicating that I had a single ring main.

A few minutes later, everything was back (the computers never went down thanks to the UPS! :-)) and I was ordering the Devolo HomePlug Adapter "Highspeed Starter Kit". This arrived last night and consisted of two RJ45 cables and two adapters that plug into the wall socket and have an Ethernet port.

One went downstairs and I plugged the router into it, and the other went upstairs into a four way expansion unit that was not connected to the UPS (I'm guessing that the UPS will clean the signal and could potentially interfere with the Ethernet, but haven't tried it). A few seconds later, and it was all working!

There is some software that can be used to set a custom encryption password for the mains side, and there is even a Linux version included on the CD, but I haven't bothered with it yet.

The unit is rated at up to 85Mbits which is still much faster than the 8Mbit bottleneck of the ADSL connection.

It was running all last night and so far, I am very impressed. The whole thing cost about £80 from Amazon and means I should no longer have to experience the woes of losing a wireless connection at home.

OpenSUSE 10.3 upgrade and DNS fun

Over the last couple of days I've been busy tweaking my network. I've updated my main workstation from OpenSUSE 10.1 to 10.3 (having missed 10.2 completely). The new version is pretty decent and shows the continuing refinement of Linux as a desktop operating system.

The GNOME "slab" menu is pretty decent and works well. The confusion over the different software management tools (YAST vs Zenworks basically) has been resolved with a new look and feel to the software management tool. I'm not as impressed with it as the previous version as the interface is less informative, but it does work.

Getting Compiz working (for wobbly windows fun) was easy, although getting Compiz Fusion setup was more difficult. I experienced the unhelpful white screen when enabling XGL, but the Nvidia driver apparently does not need XGL for accelerated graphics, and the new whizzy effects are certainly pretty impresive (although the more advanced ones like Burn and Explode are a bit jerky on my old 5200FX graphics card).

With the number of virtual machines on my network now increasing, I was getting tired of looking up IP addresses in /etc/hosts and decided to build myself a small DNS server Solaris zone. Setting up BIND is one of those things that I always think is hard, but whenever I do it, I surprise myself how easy it is.

I opted to setup a dedicated zone because, well, the overhead is minimal and it provides a nice way of separating services. I built "dnsserver" as a sparse root zone, created /var/named and setup the zones files and /etc/named.conf. Now to be honest, I did cheat a little by using the h2n script to generate the zone information automatically, but having done that I then manually tweaked all the entries to get my A (authorative) and CNAME (canonical) entries setup correctly. A few more minutes spent on reconfiguring my other machines to use the DNS server and my "local.zone" was up and running.

I've also made tentative steps into the world of LDAP by installing Fedora Directory Server into a Centos 5.1 virtual machine. Having completed the install, I tried to setup an LDAP user, but have so far failed to get this working. Something to pick up when I have more time.

I'm still working on consolidating all my documents into a single fileserver, possibly using an iTunes server for sharing music. Will update when I've done more...