Date: Mon, 19 Oct 2009 10:26:55 -0400 From: PJ <af.gourmet@videotron.ca> To: Johan Hendriks <Johan@double-l.nl> Cc: Polytropon <freebsd@edvax.de>, freebsd-questions@freebsd.org Subject: Re: glabel clarification Message-ID: <4ADC772F.3060303@videotron.ca> In-Reply-To: <57200BF94E69E54880C9BB1AF714BBCBA57086@w2003s01.double-l.local> References: <4ADC6D89.10600@videotron.ca> <57200BF94E69E54880C9BB1AF714BBCBA57086@w2003s01.double-l.local>
index | next in thread | previous in thread | raw e-mail
Johan Hendriks wrote:
>> I understood that labeling a disk with glabel would permit the disk to
>> be switched to another system and booting from that disk would not
>> require other manupulations than adjusting network configuration,
>>
> samba,
>
>> rc.conf and a few others..
>> But what if there is already a disk on the system with the identical
>> labels in /dev/label/ ?
>> I understood that whatever the actual disk might be (ad4, ad12,
>> ad1...)would be irrelevant?
>> It would appear that the actual booting goes according to the label;
>>
> so,
>
>> if there are duplicate labels the boot will not necessarily be from the
>> newly installed disk if there is another disk with duplicate glabel
>>
> labels?
>
>> So doing a glabel seems superfluous...
>> What then is the real purpose of glabel, since the boot process seems
>>
> to
>
>> need a unique identifier?
>>
>
> Switching between machines is not what labels are for.(enlighten me if
> it is)
> As far as understand, it makes switching the drive in the same machine
> easier.
> It does not matter if labels are used, that the device is seen as
> /dev/ad0 or /dev/ad{x}.
> This makes adding and replacing disk much easier.
> Sometimes the disk numbers change when removing raid controllers or
> other hardware.
>
Yes, this is true and that is why I thought that glabel would work; I am
trying to set up my computers with identical clones that I can update
with changes on the master machine from time to time and thus prevent
data loss in case of problems. So I use ad12 as the main system; if it
were to crash I would then boot from ad6 which is identical. But the
/etc/fstab is identical in both machines. So if I boot from ad6, I will
get booted from ad12 ... so that doesn't work. It looks like we need an
unique identifier for each disk.
help
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4ADC772F.3060303>