Search
Linkdump
» Belkin WeMo
This kind of looks like the future of home automation.
Belkin WeMo
Nice feature overview
here.
X10 is cool but complicated; whereas this looks cool and simple.
» Bookcrossing
A friend pointed me at
Bookcrossing.
Seems like a great way to redistribute your old books and having some fun doing it.
The basic idea - label your old books with a unique identifier, then drop them off wherever you like. Log the 'drop' on the
Bookcrossing website for someone to pick up. If they log the collection you can track who and where the book goes. Obviously there are the usual anonymity options and if a non-
Bookcrossing person picks up the book they may choose not to join-up (its free, they make money selling accessories like custom labels and bookplates).
Pretty cool.
» Mailorder Beer
A plug and a bit of a bookmark for myself -
Beerstore in NZ does a great job of distributing beer of all kinds delivered to your door.
I've used them a few times now and they're quick and efficient - I even had one delivery with broken bottles which the couriers obviously screwed up and within a couple of days
Beerstore had another order on my doorstep no questions asked. Now thats service !
» What is a karonkka?
A friend of mine recently returned from Finland where he was examining a PhD defence - the process is called a
Karonkka.
As well as getting decked out in a full-on tux & tails they actually had ceremonial swords to boot. How cool is that ?
Be sure to read Shauns other posts on the nature of research, patents, science and technology in New Zealand.
» TED Talks
A friend of mine (cheers Eddie!) pointed me at the excellent
TED Talk series.
Subscribe to their RSS feed now.
Theres always something you can set aside 15 minutes of your time to learn about or dump to your mp3 player to listen/watch while you commute.
Recent favourites of mine have included -
'Build a brain in a supercomputer',
'Our buggy moral code',
'What brain damage can point out about our mind',
'Why are babies cute? Why is cake sweet?'
» Useful Ways to be Persuasive
I realised my Linkdump category hadn't been updated in a looong time so I'll kick start it with this link to some common-sense
ways to be persuasive.
As per the link comments in the preamble, its a bit pop-psych but theres some useful stuff to help get your head around how you can get your point of view across to other people.
» Because you need to know - Tracking the $700 Billion Bailout
It'll be interesting to see if the New York Times keeps this table up to date -
Tracking the $700 Billion Bailout.
See which financial institutions receive money and how much they get.
» Good Music - Le Pop by Katzenjammer
Discovered while reading
Popmatters list of Also-rans for 2008 -
Katzenjammers 'Le Pop' is one of those joyful albums by a band determined to put a stupid grin on your face at all costs or die trying (cf early Violent Femmes, Crowded House, Pogues).
Check out a couple of videos on YouTube - '
A bar in Amsterdam' and '
Aint no thang'
» Good Books - The Shock Doctrine
Another excellent read from
Naomi Klein -
The Shock Doctrine. I have to admit I'm only halfway through this book - mans inhumanity to man makes for tough going - however its pretty much compulsory reading for anyone that wonders how the worlds free market economy's were lead down the track they're currently on.
Essentially what Klein does is posit the idea that free market economies and reforms can only be forced through on the back of an external crisis (sometimes real and sometimes engineered). As a result those people best placed to take advantage of the reforms do extraordinarily well and the vast majority of us end up worse off - with globalisation these disparities keep getting worse as multi-nationals cease to be bound by georgraphy.
As the recent recession and American bank / finance / auto bail-outs have shown - the free market has failed to a certain extent - their own calls for deregulation have bit them on the ass and now they're going cap in hand to the very regulatory bodies they once reviled for assistance.
So even when things go wrong for the wheelers and dealers of the world - they still come out on top.
» Good Books - Killing Rommel by Stephen Pressfield
Another quick summer read -
Killing Rommel is a return to form for Stephen Pressfield - his 'Gates of Fire' was a masterpiece but after that I found 'Tides of War' and 'Last of the Amazons' to be a little dry.
His latest novel tells the tale of the
Long Range Desert Group (LRDG) and their various exploits in the North African campaign, culminating in a mission to track down and kill
Rommel.
Thursday 03 September 2009 at 8:29 pm
Discovered via
- an online backup company show how they put together their storage units -
Backblaze: Petabytes on a Budget.
Pretty impressive stuff.
Now if only they open-sourced their software
I'm guessing you could always roll your own
ZFS cluster to improve redundancy . . .
Monday 23 March 2009 at 5:34 pm
I think I'm going to have to add a 'Long Now' category because this stuff is just fascinating -
From the Long Now Blog comes a series of articles which indicate that as information density increases its lifetime decreases -
Are We Losing Our Memory ?
Some pretty awesome engineering feats are described including recovering images from tape take during the 1960's as part of the planning for the moon landings.
Wednesday 17 October 2007 at 08:44 am
One of the heads on our NetApp SAN crashed the other day (no dump file so no idea why it happened) and the second head picked up control of the other heads disk - no big problem. The crashed head just rebooted. It would have been a seamless 'issue' but the networking configuration didn't fail over with the disks. As a result I got a panicked voicemail from our DBA the following morning - I remoted into the SAN and did a manual fail-back from one head to the other.
This occurred because I tweaked the configuration to allow VLAN trunking - the NIC's were initially trunked for fail over and increased through-put. Then we realised that for SAN mirroring we need the SAN to be externally accessible rather than isolated to the SAN VLAN. We could have split the NIC's so one was on Data and one on the Storage VLAN but it we would have lost the benefits of trunking. So we enabled VLAN trunking on the SAN and the Cisco switch ports but I failed to enable the partner-relationship which is critical for successful fail over.
So if you want to make sure your IP addresses fail over properly then make sure your rc configs on both heads looks something like this (obviously the hostnames and IP addresses will be different) - the key part is the 'partner' suffix on the trunk interface config.
hostname san1
vif create multi multitrunk1 -b ip e0b e0a
vlan create multitrunk1 45 46
ifconfig multitrunk1-45 10.1.45.7 netmask 255.255.255.0 mtusize 1500 partner multitrunk1-45
ifconfig multitrunk1-46 10.1.46.1 netmask 255.255.255.0 mtusize 1500 partner multitrunk1-46
ifconfig multitrunk1-45 up
has some good rc config example files too.
Thursday 11 October 2007 at 09:08 am
I gave up reading
slashdot a few years ago but in doing so I miss occasional tidbits of useful Tech news.
I ended up reading about this on
Storagemojo - check out this
FusionIO demo. Going by the 8 DVD's in 40 sec benchmark it seems to shift about 800Mb a sec.
As per the Storagemojo take on the demo - 'if it seems to good to be true, it usually is'.
Saturday 26 May 2007 at 12:17 pm
A good guide us to place LUN's into Volumes grouped by similar Snapshot or Snapmirror regimes (as this functionality occurs at the Volume level). I think the techy term for grouping LUN's in this way is a 'Consistancy Group' - anything you need to get Snap'd together should be kept in the same Volume.
Another thing I picked up was that when allocating space for LUN's be sure to allocate twice the space you need to allow for Snapshots. This space requirement supercedes the default 20% allocated at the Volume level. For LUN based Snapshots the agent software on the host itself (eg SnapDrive for Windows or SnapDrive for Exchange) manages the Snapshot - it interacts with the SAN to ensure this happens properly but the SAN itself has no knowledge of whats inside the LUN.
What this means is that if every block in the LUN changes you need at least as much space again for the Snapshot or you'll get a disk-space error. Its unlikely this would occur - a situation in which it might would be a drive defragment which touched every block.
Thursday 17 May 2007 at 6:12 pm
If you're considering getting a SAN or already have one you should check out the
Toasters mailing list. I've searched the interweb for equivalent lists for HDS and EMC but haven't found any equivalent (that isn't actually hosted by the vender itself).
Its completely independent of NetApp but is an excellent place to ask questions or search for answers in the list archives.
A good overview of the list is
here.
Thursday 17 May 2007 at 11:22 am
When you get down to the nitty gritty of configuring an iSCSI connection theres not actually a nice guide to getting this done. Sure there are plenty of docs and white-papers on the topic but many of them are either to detailed or not detailed enough (NetApp, Sun and Microsoft are all guilty of making something which should be simple more difficult than it needs to be).
From a Solaris perspective there are a couple of really good guides that fill in the blanks between the Solaris & NetApp documentation:
*
OpenSolaris and iSCSI: NetApp Makes it Easy
*
iSCSI Examples
Thursday 17 May 2007 at 10:32 am
A cunning way to do your SAN backups:
Schedule a job to mount your LUN's to the backup server and backup a SnapShot to tape from there. Requires a bit of scripting and tweaking but it should provide much more flexibility than trying to backup each server individually.
That way you can avoid being reamed by backup software vendors on a per host basis. You may still opt to do an NTBackup to file for servers and applications but the databases will reside on the SAN and get backed up to tape.
Thursday 17 May 2007 at 10:00 am
I'm not a storage person so it took me awhile to get my head around the terminology. I suspect Sysadmins who host databases get harassed regularly by their DBA's about this stuff on a regular basis and as a result are much more intimately acquainted with this stuff than I am. One feature that helps the Sysadmin stay out of DBA initiated RAID-config-hell is that DataOnTap (the NetApp OS) only supports RAID 4 or RAID DP (similar to RAID 6) - note that the 'D' in DP is for 'Diagonal' not 'Dual'.
In NetApp land -
An Aggregate is a collection of disks - this is fairly straightforward. One thing to remember is that for every aggregate you lose a disk to parity data - fine if you have multiple shelves of disks or groups of disks of different capacity (eg you might aggregate 7 15k 72Gb disks and another aggregate of 7 10k 300Gb disks) but not really needed if you have only a single shelf with all disks the same. I guess there are plenty of reasons you might want different aggregates on a single shelf but if you're not doing anything fancy you may as well stick with one).
A Volume is a chunk of space within an aggregate - note that by default the DataOnTap OS is in vol0 within aggr0. Don't mess with vol0! If you're doing CIF's or NFS sharing (eg NAS type functionality) then you'd dish up your shares at a volume level.
A LUN is a SCSI term (Logical Unit Number) to reference an individual disk.
Thursday 17 May 2007 at 09:41 am
We bit the bullet and bought two NetApp 'toasters' - a FAS270 for our DR/UAT site and a FAS270c ('c' for clustered) for our Prod site.
For 2Tb of storage apiece they were actually pretty cheap - we'll SnapMirror between the two sites, we'll use the SnapManager tools for SQL, Oracle and Exchange and iSCSI as our transport medium (Fibre Channel is to expensive and complicated although we will use it between our backup server and tape drive).
So I'll be collecting some tips here as we put real apps on these systems.
You can team your Nic's in a couple of ways - either singletrunk or multitrunk mode. Single mode is purely for failover - one connection dies and the other will pick up the connection. Multi mode provides failover, link aggregation and load-balancing.
If you have more than two Nic's you can do this via the web interface, if you've only got two then you'll have to use the console (obviously you can't reconfigure a Nic if its already being used for something else; eg if you 'ifconfig e0 down' you'll lose your connectivity to configure the trunking).
To create a multi trunk virtual interface called multitrunk1 with e0 and e1 issue the following command on the console:
vif create multi multitrunk1 e0 e1
Then to configure it do the usual:
ifconfig multitrunk1 [ip address] netmask [netmask address]
And you can brink it up or down in the same way as any other interface.
One important point to note is that if you do this from the console be sure to update /etc/rc & /etc/host to reflect the vif or you'll lose the interface after a reboot. The web interface does write this info to these files but its worth double-checking that the updates have been made.
