Ext4 hacker Ted Ts'o converts his laptop

Posted Jul 4, 2008 19:14 UTC (Fri) by k8to (guest, #15413)
In reply to: Ext4 hacker Ted Ts'o converts his laptop by Los__D
Parent article: Ext4 hacker Ted Ts'o converts his laptop

The reason for this is historical.

On really old Unixes, filesystems *would* become mangled with some regularity.  You brought
systems down and fscked them regularly in order to discover where, not if, things had gone
wrong, and restore them.  A small /boot type partion was relevant in order to decrease the
likelyhood that a serious error would occur on the boot filesystem.

On Linux, which has had reliable filesystems since at least ext2fs became widely available
(1994 or so?) this wasn't really an issue.  However, because Linux boots with assistance from
a poorly maintained ROM interface, which tends to often fail to provide rom-call access to the
entire disk, a /boot filesystem can make sense for the general case, since it doesn't really
cause harm when it is not needed.

However with the advent of generally available 48 bit (or whatever, the larger addressing
version) of LBA in BIOS implementations, we haven't had to deal with this problem for some
years.  Current linuxes seem to not require a /boot partition, that I have dealt with.  I
certainly haven't configured any production systems with a /boot partition for a long time.

Ext4 hacker Ted Ts'o converts his laptop

Posted Jul 4, 2008 20:17 UTC (Fri) by nix (subscriber, #2304) [Link]

There's another reason to use /boot: if your boot program won't boot off 
the filesystem or block device that your main OS is on.

A major example of this is any of the more complicated RAID setups. Most 
of my systems are LVM atop RAID-5 or RAID-6, sometimes NBDed to other 
remote systems (using write-mostly to avoid incredible sloth). Obviously 
you want / to be RAIDed, because if /lib or /etc dies you're in big 
trouble: but it's highly unlikely that LILO or whatever could boot off 
that. So you make a smaller RAID-0 /boot, with an initramfs or whatever so 
that it can bring up RAID and LVM, and put your kernels on there. Bingo.

Ext4 hacker Ted Ts'o converts his laptop

Posted Jul 5, 2008 8:09 UTC (Sat) by Los__D (guest, #15263) [Link] (1 responses)

I do it simply to make sure that I don't do nasty things with my kernel by accident.

Anyway, I still don't see the any problems in relation to the OP's mentioning of downtime
problems.

Ext4 hacker Ted Ts'o converts his laptop

Posted Jul 5, 2008 8:09 UTC (Sat) by Los__D (guest, #15263) [Link]

Ehm, that came out a bit funny, but I guess you understand.