CentOS - Jun 2015 - LVM hatred, was Re: /boot on a separate partition?

On Wed, June 24, 2015 16:11, Chuck Campbell wrote:
>
> Is there an easy to follow "howto" for normal LVM administration
> tasks. I get tired of googling every-time I have to do something
> I don't remember how to do regarding LVM, so I usually just
> don't bother with it at all.
>
> I believe it has some benefit for my use cases, but I've been
> reticent to use it, since the last time I got LVM problems, I
> lost everything on the volume, and had to restore from backups
> anyway. I suspect I shot myself in the foot, but I
> still don't know for sure.
>
At the risk of some ridicule I suggest that you look at installing
Webmin.  It is a web based system administration tool that I find
invaluable.  The two most common complaints I encounter when I discuss
its merits are 'security' and 'transparency'.

The security issue is trivially dealt with. Install Webmin and
configure it to listen on 127.0.0.1 using its standard port TCP10000. 
Install Firefox on the same host and then run firefox from an 'ssh -Y'
session using the --noremote option.  If you are totally paranoid then
firewall TCP10000 as well, configure Webmin to use https only, and
then only start the webmin service when you are performing
maintenance.

There are less draconian measures that are in my opinion equally
secure from a practical standpoint but I am sure that you can figure
those out on your own.

The transparency issue is really unanswerable.  There exists a school
of thought that if you are going to administer a Linux system (or OS
of the proponent's choice) then you should learn the command syntax of
every command that you are called upon to use.  This is the
one-and-only path to enlightenment.  Like upholding motherhood and
promoting the wholesomeness of apple-pie this sort of moralizing
really brooks no answer. You can guess my opinion on that line of
puritanism.

As you have painfully discovered, infrequently used utilities and
commands are difficult to deal with.  The process of learning, or
relearning, the correct arcana is particularly noisome given the
notorious inconsistency of syntaxes across different utilities and the
spotty coverage of up-to-date documentation.  Google can be a
dangerous guide given the wide variation of practice across differing
flavours of *nix and the widespread aversion to providing dates on
writings. In consequence I consign transparency arguments and their
proponents to the religious fanatic file.  Nothing personal but there
is no point in arguing belief systems.

If you want to get infrequently performed sysadmin tasks done reliably
and with a minimum of fuss use something like Webmin and get on with
the rest of your life.


-- 
***          e-Mail is NOT a SECURE channel          ***
        Do NOT transmit sensitive data via e-Mail
James B. Byrne                mailto:ByrneJB at Harte-Lyne.ca
Harte & Lyne Limited          http://www.harte-lyne.ca
9 Brockley Drive              vox: +1 905 561 1241
Hamilton, Ontario             fax: +1 905 561 0757
Canada  L8E 3C3

On 06/25/2015 11:03 AM, James B. Byrne wrote:
> On Wed, June 24, 2015 16:11, Chuck Campbell wrote:
>> Is there an easy to follow "howto" for normal LVM
administration
>> tasks. I get tired of googling every-time I have to do something
>> I don't remember how to do regarding LVM, so I usually just
>> don't bother with it at all.
>>
>> I believe it has some benefit for my use cases, but I've been
>> reticent to use it, since the last time I got LVM problems, I
>> lost everything on the volume, and had to restore from backups
>> anyway. I suspect I shot myself in the foot, but I
>> still don't know for sure.
>>
> At the risk of some ridicule I suggest that you look at installing
> Webmin.  It is a web based system administration tool that I find
> invaluable.  The two most common complaints I encounter when I discuss
> its merits are 'security' and 'transparency'.
>
> The security issue is trivially dealt with. Install Webmin and
> configure it to listen on 127.0.0.1 using its standard port TCP10000.
> Install Firefox on the same host and then run firefox from an 'ssh
-Y'
> session using the --noremote option.  If you are totally paranoid then
> firewall TCP10000 as well, configure Webmin to use https only, and
> then only start the webmin service when you are performing
> maintenance.
>
> There are less draconian measures that are in my opinion equally
> secure from a practical standpoint but I am sure that you can figure
> those out on your own.
>
> The transparency issue is really unanswerable.  There exists a school
> of thought that if you are going to administer a Linux system (or OS
> of the proponent's choice) then you should learn the command syntax of
> every command that you are called upon to use.  This is the
> one-and-only path to enlightenment.  Like upholding motherhood and
> promoting the wholesomeness of apple-pie this sort of moralizing
> really brooks no answer. You can guess my opinion on that line of
> puritanism.
>
> As you have painfully discovered, infrequently used utilities and
> commands are difficult to deal with.  The process of learning, or
> relearning, the correct arcana is particularly noisome given the
> notorious inconsistency of syntaxes across different utilities and the
> spotty coverage of up-to-date documentation.  Google can be a
> dangerous guide given the wide variation of practice across differing
> flavours of *nix and the widespread aversion to providing dates on
> writings. In consequence I consign transparency arguments and their
> proponents to the religious fanatic file.  Nothing personal but there
> is no point in arguing belief systems.
>
> If you want to get infrequently performed sysadmin tasks done reliably
> and with a minimum of fuss use something like Webmin and get on with
> the rest of your life.
>
>
That is fine until suddenly you find yourself without your crutch.

-- 
Stephen Clark
*NetWolves Managed Services, LLC.*
Director of Technology
Phone: 813-579-3200
Fax: 813-882-0209
Email: steve.clark at netwolves.com
http://www.netwolves.com

James B. Byrne wrote:
>
> On Wed, June 24, 2015 16:11, Chuck Campbell wrote:
>>
>> Is there an easy to follow "howto" for normal LVM
administration
>> tasks. I get tired of googling every-time I have to do something
>> I don't remember how to do regarding LVM, so I usually just
>> don't bother with it at all.
>>
>> I believe it has some benefit for my use cases, but I've been
>> reticent to use it, since the last time I got LVM problems, I
>> lost everything on the volume, and had to restore from backups
>> anyway. I suspect I shot myself in the foot, but I
>> still don't know for sure.
>
> At the risk of some ridicule I suggest that you look at installing
> Webmin.  It is a web based system administration tool that I find
> invaluable.  The two most common complaints I encounter when I discuss
> its merits are 'security' and 'transparency'.
<snip>
Back in '06 or '07, I installed webmin on the RHEL systems I was working
on. It was a tremendous help installing and configuring openLDAP, whose
tools, at least through '08, were very definitely *NOT* ready for prime
time. Webmin let me beat it into submission.

       mark

At Thu, 25 Jun 2015 11:03:18 -0400 CentOS mailing list <centos at
centos.org> wrote:
> 
> 
> On Wed, June 24, 2015 16:11, Chuck Campbell wrote:
> >
> > Is there an easy to follow "howto" for normal LVM
administration
> > tasks. I get tired of googling every-time I have to do something
> > I don't remember how to do regarding LVM, so I usually just
> > don't bother with it at all.
> >
> > I believe it has some benefit for my use cases, but I've been
> > reticent to use it, since the last time I got LVM problems, I
> > lost everything on the volume, and had to restore from backups
> > anyway. I suspect I shot myself in the foot, but I
> > still don't know for sure.
> >
> 
> At the risk of some ridicule I suggest that you look at installing
> Webmin.  It is a web based system administration tool that I find
> invaluable.  The two most common complaints I encounter when I discuss
> its merits are 'security' and 'transparency'.
> 
> The security issue is trivially dealt with. Install Webmin and
> configure it to listen on 127.0.0.1 using its standard port TCP10000. 
> Install Firefox on the same host and then run firefox from an 'ssh
-Y'
> session using the --noremote option.  If you are totally paranoid then
> firewall TCP10000 as well, configure Webmin to use https only, and
> then only start the webmin service when you are performing
> maintenance.
> 
> There are less draconian measures that are in my opinion equally
> secure from a practical standpoint but I am sure that you can figure
> those out on your own.
> 
> The transparency issue is really unanswerable.  There exists a school
> of thought that if you are going to administer a Linux system (or OS
> of the proponent's choice) then you should learn the command syntax of
> every command that you are called upon to use.  This is the
> one-and-only path to enlightenment.  Like upholding motherhood and
> promoting the wholesomeness of apple-pie this sort of moralizing
> really brooks no answer. You can guess my opinion on that line of
> puritanism.
HA!  You only really need to learn *one* command: the man command.  The man 
provides 'enlightenment' for all other commands:

man vgdisplay
man lvdisplay
man lvcreate
man lvextend
man lvresize
man lvreduce
man lvremove
man e2fsck
man resize2fs

These are the only LVM commands I use regularly (yes there a a pile more, but
most are rarely used and a handful only used in startup/shutdown scripts or
when rescuing) and I often end up use the man command to refresh my memory of
the command options. 
> 
> As you have painfully discovered, infrequently used utilities and
> commands are difficult to deal with.  The process of learning, or
> relearning, the correct arcana is particularly noisome given the
> notorious inconsistency of syntaxes across different utilities and the
> spotty coverage of up-to-date documentation.  Google can be a
> dangerous guide given the wide variation of practice across differing
> flavours of *nix and the widespread aversion to providing dates on
> writings. In consequence I consign transparency arguments and their
> proponents to the religious fanatic file.  Nothing personal but there
> is no point in arguing belief systems.
Right, expecting a *web search* to give *correct* command documentation is 
problematical.  Using the local system man pages often works better, since the 
man pages installed with the installed utilities will cover the *installed* 
version and not the version that might be installed on a *different* distro, 
etc.
> 
> If you want to get infrequently performed sysadmin tasks done reliably
> and with a minimum of fuss use something like Webmin and get on with
> the rest of your life.
> 
> 
-- 
Robert Heller             -- 978-544-6933
Deepwoods Software        -- Custom Software Services
http://www.deepsoft.com/  -- Linux Administration Services
heller at deepsoft.com       -- Webhosting Services

On Thu, 2015-06-25 at 11:50 -0400, Robert Heller wrote:
> At Thu, 25 Jun 2015 11:03:18 -0400 CentOS mailing list <
> centos at centos.org> wrote:HA!  You only really need to learn *one* 
> command: the man command. 
>  The man 
> provides 'enlightenment' for all other commands:
> man vgdisplay
> man lvdisplay
> man lvcreate
> man lvextend
> man lvresize
> man lvreduce
> man lvremove
> man e2fsck
> man resize2fs
> 
> These are the only LVM commands I use regularly (yes there a a pile 
> more, but most are rarely used and a handful only used in 
> startup/shutdown scripts or when rescuing) 

There may be numerous commands... but isn't it pretty obvious what each
one of them do?  Often lv<tab><tab> is plenty of hinting to get to
the
right thing.  And each of the commands uses the same syntax for
options.
>>spotty coverage of up-to-date documentation.  Google can be a
>>dangerous guide given the wide variation of practice across
>>differing..
Yes, exactly. DO NOT USE GOOGLE - USE THE &^@&$^* DOCUMENTATION!
> Right, expecting a *web search* to give *correct* command
> documentation is problematical.  Using the local system man pages 
> often works better, since the man pages installed with the installed 
> utilities will cover the *installed* version and not the version that 
> might be installed on a *different*
+1
>>If you want to get infrequently performed sysadmin tasks done
>>reliably and with a minimum of fuss use something like Webmin and 
>>get on with the rest of your life.
And take notes!  You are sitting at a computer after all.

--
Adam Tauno Williams <mailto:awilliam at whitemice.org> GPG D95ED383
Systems Administrator, Python Developer, LPI / NCLA

Robert Heller wrote:
> At Thu, 25 Jun 2015 11:03:18 -0400 CentOS mailing list <centos at
centos.org>
> wrote:
>> On Wed, June 24, 2015 16:11, Chuck Campbell wrote:
>> >
>> > Is there an easy to follow "howto" for normal LVM
administration
>> > tasks. I get tired of googling every-time I have to do something
>> > I don't remember how to do regarding LVM, so I usually just
>> > don't bother with it at all.
>> >
>> > I believe it has some benefit for my use cases, but I've been
>> > reticent to use it, since the last time I got LVM problems, I
>> > lost everything on the volume, and had to restore from backups
>> > anyway. I suspect I shot myself in the foot, but I
>> > still don't know for sure.
>>
>> At the risk of some ridicule I suggest that you look at installing
>> Webmin.  It is a web based system administration tool that I find
>> invaluable.  The two most common complaints I encounter when I discuss
>> its merits are 'security' and 'transparency'.
<snip>
> HA!  You only really need to learn *one* command: the man command.  The
> man provides 'enlightenment' for all other commands:
>
> man vgdisplay
> man lvdisplay
> man lvcreate
> man lvextend
> man lvresize
> man lvreduce
> man lvremove
> man e2fsck
> man resize2fs
<snip>

You missed one: man man.

        mark

On 6/25/2015 8:50 AM, Robert Heller wrote:
> man vgdisplay
> man lvdisplay
> man lvcreate
> man lvextend
> man lvresize
> man lvreduce
> man lvremove
> man e2fsck
> man resize2fs
man xfs_growfs



-- 
john r pierce, recycling bits in santa cruz