Partition naming, fstab, and geli
smithi at nimnet.asn.au
Mon Nov 16 16:04:40 UTC 2009
In freebsd-questions Digest, Vol 285, Issue 2, Message 2
On Sun, 15 Nov 2009 19:23:15 -0700 David Allen wrote:
> Say I have performed a standard installation of FreeBSD onto a single IDE
> drive with the following entries in /etc/fstab:
> /dev/ad0s1b none swap sw 0 0
> /dev/ad0s1a / ufs rw 1 1
> /dev/ad0s1d /var ufs rw 2 2
> /dev/ad0s1e /tmp ufs rw 2 2
> /dev/ad0s1f /usr ufs rw 2 2
> Then I added more drives.
> 1. The Handbook suggests there is a convention that when partitioning a a
> drive that's been added, to label the first new partition on that drive as
> 'e' as opposed to 'a' (which is reserved for the /root partition). Does
> the following satisfy that convention, or would starting with 'a' in each
> case make more sense?
> /dev/ad1e /foo1 ufs rw 2 2
> /dev/ad1f /bar1 ufs rw 2 2
> /dev/ad1g /baz1 ufs rw 2 2
> /dev/ad2e /foo2 ufs rw 2 2
> /dev/ad2f /bar2 ufs rw 2 2
> /dev/ad3e /foo3 ufs rw 2 2
> /dev/ad3f /bar3 ufs rw 2 2
If you added these with sysinstall (or sade) it will tend to choose 'd'
for the first partition on other than the / partition (which is named
'a' on install). Or at least, it's always started with 'd' for me :)
But if you're doing it manually starting with 'e' is fine. I suspect
the handbook section you quoted to Polytropon later is more an example
than definitive. You can happily mount an 'a' partition from another
drive that was once a system disk; it's more of a convention really.
> 2. My second question is in regards to using the 'xx' fstype to have the
> system ignore that device.
> Consider, for example, a geli encrypted partition. The .eli device
> doesn't exist at boot time. I discovered by accident that the system
> won't boot with an fstab entry for a device that doesn't exist. So if I
> was to record an entry in fstab, I couldn't use
> /dev/ad1e.eli /home/david/private ufs rw 0 0
> Does that mean that the following is what's typically to record fstab
> entries for ignored devices?
> /dev/ad1e.eli /home/david/private xx rw 0 0
> /dev/ad3e /fake xx rw 0 0
> /dev/ad3f /reserved xx rw 0 0
Yes. Here I must differ with Polytropon, though your format for the
options isn't perhaps quite right. From an old fstab here:
# Device Mountpoint FStype Options Dump Pass#
/dev/acd0 /cdrom cd9660 ro,noauto 0 0
/dev/ad0s1 /dos msdosfs ro,noauto 0 0
/dev/ad0s2b none swap sw 0 0
/dev/ad0s2a / ufs rw 1 1
/dev/ad0s2d /var ufs rw,noatime 2 2
/dev/ad0s2e /usr ufs rw,noatime 2 2
/dev/ad0s4d /paqi4.5 ufs ro,noauto,nodev,noexec,nosymfollow,noatime 2 3
/dev/ad0s4e /paqi4.5/var ufs ro,noauto,nodev,noexec,nosymfollow,noatime 2 4
/dev/ad0s4f /paqi4.5/usr ufs ro,noauto,nodev,noexec,nosymfollow,noatime 2 4
# 25Apr06 ext 20Gb USB disk. DON'T autoadd these, deadly if da0 absent!
# .. xx fsopts, everything incl fsck must ignore ..
/dev/da0s3d /usbdsk ufs xx,noauto,nosymfollow 3 3
/dev/da0s3e /usbdsk/var ufs xx,noauto,nosymfollow 4 4
/dev/da0s3f /usbdsk/usr ufs xx,noauto,nosymfollow 4 4
# 26May06 shintaro 1G flashdrive .. just doc, can't mount using these ..
/dev/da0s1 /flash/dos msdosfs xx,noauto 0 0
/dev/da0s2d /flash/ufs ufs xx,noauto,noatime 3 3
/dev/da0s3d /flash/pvt ufs xx,noauto,noatime 3 3
As you say they're useful for doc, and not hard to edit into action.
Note the additions above were assigned starting at 'd' by sysinstall.
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