File System Design part 1, XFS

rchapman writes "Generally, file systems are not considered "sexy." When a young programmer wants to do something really cool, his or her first thought is generally not "Dude, two words... File System." However, I am what is politely termed "different." I find file systems very interesting and they have seldom been more so than they are right now. Hans Reiser is working on getting Reiser4 integrated into the Linux kernel, the BSD's are working on getting a journaled file system together, and Sun Microsystems just recently released a beta of ZFS into OpenSolaris. "

Comments

File system design

[Bogtha]

If you're interested in this, you'll probably also be interested in Practical File System Design with the Be File System (PDF), by Dominic Giampaolo, the designer of the Be file system. There's also a Slashdot review of this book.

Blatant error

[lostlogic]

Sector size on hard disks is 512 bytes, not 512kbytes. WTF, don't act like an authority and be a dumbass. Imagine the data waste if we actually had 512k physical sectors on disks.

Also the scaling numbers are completely hokey.

obligatory

[DrSkwid]

If you like on disk file systems you should read Venti: a new approach to archival storage.

Plan9's primary on-disk storage is Fossil, which runs in user mode. (Plan9 doesn't have a super user)

You can run arbitrary programs in Plan9 that present a file/folder directory structure by using the common 9P protocol. All devices look like files and folders and can be manipulated like any other, even at the permission level.

For instance, I have an image mounter that takes a tga file and presents 1 folder containing 4 files, red, green, blue and alpha.
I can then use any tool I like to manipulate those files using the file semantics we are all familiar with. I even have a flag that mounts the files as textual rather than binary, i.e :
00 00 ff ff
00 00 ff ff
ff ff 00 00
ff ff 00 00

and I can do image processing with awk !

I concur, Mod Parent Up

[NixLuver]

from TFA:
"There is a minimum size you can write to or read from the disc. This minimum size is called a "sector," and is usually around 512k. So, unless you really like 512k files, it is very likely that you will end up either wasting space or cutting off the end of the file if your file system doesn't deal with this."

This is clearly not a typo - which is what I was certain I would find when I did RTFA. This guy has a basic, fundamental flaw in his understanding of the very thing he's writing an article about. This is a non-starter, IMO. Combine that with poor sentence structure and bad scansion ... I mean:

"Note: My ibook has a "30 gig" drive. This is bullshit and I'll tell you why: Drives are defined by the binary definition of mega, kilo and giga. For example, a kilobyte is not 1000 bytes, but actually 1024 bytes. However, your HD manufacturer uses the metric definitions, even up to gigabytes. Now I can see you thinking..."But Wait Mr. Mad Penguin Person...Thats patently ridiculous and means they are lying on the box." Yah... "

If I'd written something like that, I'd delete it right away and start from scratch.