CentOS - Feb 2019 - What files to edit when changing the sdX of hard drives?

Nicolas Kovacs wrote:
> Le 28/02/2019 ? 04:12, Jobst Schmalenbach a ?crit?:
>
>> I want to lock in the SDA/SDB/SDC for my drives
>
> In short : use UUIDs or labels instead of hardcoding /dev/sdX.
>
> https://wiki.archlinux.org/index.php/persistent_block_device_naming
Yeah - I strongly believe in labels, given the fact that *no* one can
remember a UUID....

      mark

On Thu, Feb 28, 2019 at 11:52 AM mark <m.roth at 5-cent.us> wrote:
> Nicolas Kovacs wrote:
> > Le 28/02/2019 ? 04:12, Jobst Schmalenbach a ?crit :
> >
> >> I want to lock in the SDA/SDB/SDC for my drives
> >
> > In short : use UUIDs or labels instead of hardcoding /dev/sdX.
> >
> > https://wiki.archlinux.org/index.php/persistent_block_device_naming
>
> Yeah - I strongly believe in labels, given the fact that *no* one can
> remember a UUID....
>
>       mark
>
ls -l /dev/disk/by-uuid

(copy)

(paste)



-- 

*Matt Phelps*

*Information Technology Specialist, Systems Administrator*

(Computation Facility, Smithsonian Astrophysical Observatory)

Center for Astrophysics | Harvard & Smithsonian


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On 2/28/19 11:02 AM, Phelps, Matthew wrote:
> On Thu, Feb 28, 2019 at 11:52 AM mark <m.roth at 5-cent.us> wrote:
> 
>> Nicolas Kovacs wrote:
>>> Le 28/02/2019 ? 04:12, Jobst Schmalenbach a ?crit :
>>>
>>>> I want to lock in the SDA/SDB/SDC for my drives
>>>
>>> In short : use UUIDs or labels instead of hardcoding /dev/sdX.
>>>
>>> https://wiki.archlinux.org/index.php/persistent_block_device_naming
>>
>> Yeah - I strongly believe in labels, given the fact that *no* one can
>> remember a UUID....
>>
>>        mark
>>
> 
> ls -l /dev/disk/by-uuid
> 
> (copy)
> 
> (paste)
> 
I second Mark about filesystem labels. Labels you can read and type. 
UUIDs you can only copy and paste. Yes I did type them a few times, 
but... With upside there certainly comes downside of filesystem labels: 
if you are moving storage around you sometimes can hit the situation of 
having two identical labels. Which during last couple of decades I was 
able to get around.

Valeri
> 
> 
-- 
++++++++++++++++++++++++++++++++++++++++
Valeri Galtsev
Sr System Administrator
Department of Astronomy and Astrophysics
Kavli Institute for Cosmological Physics
University of Chicago
Phone: 773-702-4247
++++++++++++++++++++++++++++++++++++++++

> Nicolas Kovacs wrote:
>> Le 28/02/2019 ? 04:12, Jobst Schmalenbach a ?crit?:
>>
>>> I want to lock in the SDA/SDB/SDC for my drives
>>
>> In short : use UUIDs or labels instead of hardcoding /dev/sdX.
>>
>> https://wiki.archlinux.org/index.php/persistent_block_device_naming
>
> Yeah - I strongly believe in labels, given the fact that *no* one can
> remember a UUID....
UUIDs can be helpful to automate things. On the other side they make
things more difficult than needed.

In my example I had two quite large servers with existing hardware. One of
the servers was already installed and in production. I had to clone the
hole system onto the second box but make sure that all UUIDs are unique in
the end.

Back in the old days that was an very easy task. But now, the hole system
consisted of 91 UUIDs for block devices/LVM/filesystems alone, with
additional UUIDs for other devices like ethernet interfaces.

I had a lot of fun!

Regards,
Simon

Phelps, Matthew wrote:
> On Thu, Feb 28, 2019 at 11:52 AM mark <m.roth at 5-cent.us> wrote:
>> Nicolas Kovacs wrote:
>>> Le 28/02/2019 ? 04:12, Jobst Schmalenbach a ?crit :
>>>> I want to lock in the SDA/SDB/SDC for my drives
>>>
>>> In short : use UUIDs or labels instead of hardcoding /dev/sdX.
>>>
>>> https://wiki.archlinux.org/index.php/persistent_block_device_naming
>>
>> Yeah - I strongly believe in labels, given the fact that *no* one can
>> remember a UUID....
>
> ls -l /dev/disk/by-uuid
> (copy)
> (paste)
That is, of course, assuming you have a running system, that you haven't
replaced a hard drive, an MDraid's not giving you trouble, etc.

And oh, I put that in another system, and it's also got partition one
labled boot... so? I'm not trying to boot off of it, I'm going to mount
it
on /mnt.

No, I dislike UUIDs. I dislike, strongly, lots of extra typing that
doesn't really get me anything. MAYBE, if you're in a Google or Amazon
datacenter, with 500,000 physical servers (I phone interviewed with them
10 years ago)... but short of that? Nope.

      mark