a cursory mention of software updates.

Troubleshooting.

Of course, the troubleshooting chapter isn't supposed to be an exhaustive compendium of errors.  That's what the Internet is for.  We've listed only error messages that lend themselves to easy solutions, or to illustrating some troubleshooting technique.

That means that messages like the following, which is a flat-out Xen / Linux bug (fixed in RedHat's .14, not sure about other distros) simply don't appear:

Bad pte = e5707067, process = ???, vm_flags = 100073, vaddr = 252000
 [<c0453809>] vm_normal_page+0xb7/0xd3
 [<c045454c>] unmap_vmas+0x3d1/0x761
 [<c0458f3c>] exit_mmap+0x6d/0xe4
 [<c041abd4>] mmput+0x25/0x69
 [<c047084f>] flush_old_exec+0x62c/0x8b2
 [<c046fcd7>] kernel_read+0x32/0x43
 [<c048d0f1>] load_elf_binary+0x494/0x15e4
 [<c0467043>] do_sync_read+0xb6/0xf1
 [<c044d4af>] __alloc_pages+0x57/0x282
 [<c04dcc45>] copy_from_user+0x31/0x5d
 [<c04dcc45>] copy_from_user+0x31/0x5d
 [<c046fa8a>] search_binary_handler+0x99/0x219
 [<c04713bf>] do_execve+0x158/0x1f5
 [<c040337d>] sys_execve+0x2a/0x4a
 [<c040534f>] syscall_call+0x7/0xb
 ======================

It seems like it's dishonest to describe only problems that we've solved.  But what we don't know -- well, that would fill volumes and be dispiriting.