Monday, 23 June 2008
Open Suse 11 ...
medieval emoticons?
However the nineteenth century is not the fourteenth. Shep argues that some of the annotations in medieaval manuscripts are the precursors to emoticons. Other scholars argue differently.
Whatever the truth, it's interesting how different cultures deal with texts and structure them. For me the question is, do you see similar scribbles in greek and roman manuscripts, be they highlighting or be they the analogs of emoticons, to add metadata to text?
University Computing part ii
Thursday, 19 June 2008
Wither computing in universities?
- filestore and repository services - where work in progress can be stored with the assurance it can be backed up and a place for the long term storage of published work, be it papers, seminar videos or whatever
- access to lms and allied teaching systems
- access to discipline specific network resources - be they online journals, specialist datasets, or whatever
- email and web access - including resources such as collaboration servers
Sunday, 15 June 2008
iambic pentameters and decryption
So a few days ago I was reading about the Oxyrhyncus papyri and suddenly was struck by something:
Latin was originally written with dots as work separators so text would look something like this:
the.cat.sat.on.the.mat
and greek was written without separators like this
thecatsatonthemat
and some time round about the first century the Romans changed from the original dots-as-separators style to the greek style which must have made text very difficult to read, even if in an inflected language like latin you have some intrinsic help puzzling out the relation between words. This is why people read out loud, working out which clauses formed a sentence etc etc.
The use of spaces as separators didn't come in until the 10th century, something for ever immortalised in of all things the sun fortran manual:
Consistently separating words by spaces became a general custom about the tenth century A.D., and lasted until about 1957, when FORTRAN abandoned the practice." —Sun FORTRAN Reference Manual
Anyway - why would they have such a system in Greek ? word separators seem a good idea even if you do find languages such as Thai that don't use them.
And then I had my idea. Word separators are good for prose, which is unstructured text. Inflected languages are reasonably structured which is why it more or less worked for latin. Modern English, or Dutch would be another matter, where the only real structure is word order.
But if what you were writing down is poetry it's easier. Providing you know the rythym and the rules for syllables it's easy to split up the character groups, and when you know for example there are five syllables to a line it's easy to work out, ie when the text is very structured, just the way it's easy to parse text with a computer program when it's structured and a nightmare when it's unstructured.
Anyway my $0.02 on this.
Friday, 6 June 2008
Re-engineering the student filestore design
- We like using Xserves as front ends because of the superior AFP performance
- The Xserve front ends also do a good job providing window shares
- It is easier to emulate cifs with third party software (samba) than it is afp (netatalk)
Do it Yourself NAS?
- http://schlaepfer.nine.ch/twiki/bin/view/Schlaepfer/SelfMadeNas2
- http://www.sun.com/aboutsun/pr/2008-04/sunflash.20080429.1.xml
- http://www.nexenta.com/corp/
- http://blogs.sun.com/icedawn/entry/bondin
and the choice of OpenSolaris is a good one given ZFS's ability to do copy on write and snapshots.
Why, because backing up big rapidly changing filestores is difficult due to the treewalk program. If you snapshot the filestore and then do an image level backup of the filestore you can post process it to do a synthetic incremental file level backup, which is kind of useful given that users want to restore files, not volumes.
Now the reason that everyone doesn't simply build their own NAS is that simple home built solutions don't scale well. Using a full size operating system is inefficient, as is using a conventional filesystem. ZFS addresses some of the filesystem problems, which was why NetApp got all antsy.
Big NAS solutions can handle lots of connections very efficiently, and that's down to the combination of a very efficient filesystem and very efficient minamalist operating system that is optimised to handle files and not do a lot else. FreeNAS tries to address this by using a cut down version of BSD and get some efficiency gains that way. And because it's BSD, you can run samba and netatalk to give cifs and afp support.
But it's a single box solution, and therefore limited as to connections it can handles etc etc. But it might be fun to build one to see what it can do.
Now our apple based design tries to address these problems:
The client machine connects through a content server switch (CSS) to one of the front end servers. The CSS load balances on a round robin basis, which means we can spread the load between multiple servers, add new servers, drop servers out for maintenance etc. Even though this is a NAS style solution the storage is provided by an Apple XSAN solution.
It's more complicated than I've drawn it with metadata controllers etc but essentially it's connected together by fibre through a switch, meaning that all the filers can see all the storage. This granular design makes adding more storage reasonably simple.
We also have some other things behind the scenes, such as backup drive, which is essentially provided by running rdiff when users log out to copy their changes across so we have a live copy we can then backup to tape or whatever.
It works. My problem when I start reading about clustered filestores such as exanet and isilon is twofold:
- Is their solution any more than our solution placed in a box with a badge on the outside?
- If it is more, what is the extra?