tiistaina, joulukuuta 18, 2007
Kiva tarjous
Työpaikallani on kerrankin keksitty jotain hauskaa: osta tietokoneellesi suojaa ja saat Simpsonit-elokuvan kaupan päälle.
sunnuntai, joulukuuta 09, 2007
Time Machine internals
When I browsed the contents of my Time Machine backup, I saw lots of files which had a large link count. This led me to believe OS X 10.5 backs up files by making a single copy on the backup disk and the hourly backups only have a hard link to the file if it has not been modified.
Now I'm not sure anymore.
Take the stat of these two files, which probably do not change:
$ stat -f "dev=%d devnum=%r ino=%i links=%l" "/Volumes/Isolevy/Backups.backupdb/Sarah/2007-12-09-124244/Sarah/Applications/Address Book.app/Contents/Resources/Dutch.lproj/AddressBookHelp/gfx/border_top.gif" "/Volumes/Isolevy/Backups.backupdb/Sarah/2007-12-09-134304/Sarah/Applications/Address Book.app/Contents/Resources/Dutch.lproj/AddressBookHelp/gfx/border_top.gif"
dev=234881030 devnum=0 ino=236409 links=1
dev=234881030 devnum=0 ino=236409 links=1
The inode of the two files is the same but their link count is only 1. According to my understanding of the unix file system semantics, this should not be possible! Perhaps there is some HFS+ magic involved that is visible thru the "unix" disguise OS X is wearing. I think I read somewhere that hard links were a bit difficult to implement in HFS+ and they at least used to be very slow.
Anyone have any info?
Now I'm not sure anymore.
Take the stat of these two files, which probably do not change:
$ stat -f "dev=%d devnum=%r ino=%i links=%l" "/Volumes/Isolevy/Backups.backupdb/Sarah/2007-12-09-124244/Sarah/Applications/Address Book.app/Contents/Resources/Dutch.lproj/AddressBookHelp/gfx/border_top.gif" "/Volumes/Isolevy/Backups.backupdb/Sarah/2007-12-09-134304/Sarah/Applications/Address Book.app/Contents/Resources/Dutch.lproj/AddressBookHelp/gfx/border_top.gif"
dev=234881030 devnum=0 ino=236409 links=1
dev=234881030 devnum=0 ino=236409 links=1
The inode of the two files is the same but their link count is only 1. According to my understanding of the unix file system semantics, this should not be possible! Perhaps there is some HFS+ magic involved that is visible thru the "unix" disguise OS X is wearing. I think I read somewhere that hard links were a bit difficult to implement in HFS+ and they at least used to be very slow.
Anyone have any info?
Better-looking Squeak
A blogger who likes Smalltalk has customized his Squeak installation a bit. Squeak seems like a wonderful tool, it just badly needs someone with an eye for graphic design to have a go at it
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