From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (ext-mx01.extmail.prod.ext.phx2.redhat.com [10.5.110.5]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id n9OLLVw5012916 for ; Sat, 24 Oct 2009 17:21:31 -0400 Received: from mail-yx0-f183.google.com (mail-yx0-f183.google.com [209.85.210.183]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id n9OLLDix011010 for ; Sat, 24 Oct 2009 17:21:13 -0400 Received: by yxe13 with SMTP id 13so8663305yxe.23 for ; Sat, 24 Oct 2009 14:21:12 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <29ae894c0910241354k67768707je61a9d25d3c14f6@mail.gmail.com> References: <20091023065219.GA8733@maude.comedia.it> <4AE20E43.2060006@worldspice.net> <20091024000642.GA30974@bdmcc-us.com> <29ae894c0910241004k327b0ff8w6577b83af3701753@mail.gmail.com> <29ae894c0910241354k67768707je61a9d25d3c14f6@mail.gmail.com> Date: Sat, 24 Oct 2009 14:21:12 -0700 Message-ID: Subject: Re: [linux-lvm] Total free space using added VGs and LVs From: Lou Arnold Content-Type: multipart/alternative; boundary=001636c926cd6f98280476b4e8e7 Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: To: LVM general discussion and development --001636c926cd6f98280476b4e8e7 Content-Type: text/plain; charset=ISO-8859-1 Brem, I agree. I thought it should be possible. Perhaps someone else can try it and let us know in a future blog. I just don't have enough experience to take it farther. Regards, Lou. On Sat, Oct 24, 2009 at 1:54 PM, brem belguebli wrote: > Hi Lou, > > Who is talking about unmounting root ? > > I'm just saying shrinking should be possible online as long as some > conditions are met (FS usage less than X %, reduced fragmentation ...) > > Of course, this kind of procedure requiring a max of caution because > of the high risk of data loss, I'm not sure it'll get implemented in > the current tools. > > > > 2009/10/24, Lou Arnold : > > Hahaha. Brem, you and I think alike. If you can do it let me know. I > don't > > think people can think of a way to keep the system on-line and yet > dismount > > root so that LVM commands can work on it. If you can make it work, I'll > buy > > you a virtual beer. > > Regards, > > Lou. > > > > On Sat, Oct 24, 2009 at 10:04 AM, brem belguebli > > wrote: > > > >> It's non sense arguing that LVM is not intended for root due to the > >> fact that you cannot shrink it (growing online is operational and > >> works fine). > >> > >> This is the only thing that is not allowed, though technically could > >> it be possible. > >> > >> > >> > >> 2009/10/24, Lou Arnold : > >> > Haha, Yes, it would have been nice for someone to have told me about > >> LVM and > >> > root. It would have saved literally days of time. But my work is > >> > experimental and never with production system. In any case, now I know > >> > better. > >> > > >> > As for the LiveCD suggestion, I did not intend to discount it. I had > in > >> fact > >> > tried it several times, but with some success. It probably just a > >> > matter > >> of > >> > finger problems for the failures. But I truly expected a graceful > >> > dismantling process without the need of shutting down the system. > >> > > >> > This was in fact a good experience. When you have to dig into things > to > >> > understand why something works or doesn't work, you are always luckier > >> than > >> > if things go perfectly right from the beginning. > >> > > >> > Thanks to everyone for your help. > >> > Lou. > >> > > >> > > >> > > >> > On Fri, Oct 23, 2009 at 5:06 PM, Brian McCullough > >> wrote: > >> > > >> >> On Fri, Oct 23, 2009 at 01:41:23PM -0700, Lou Arnold wrote: > >> >> > Ryan, Thanks for your suggestion. I know it works, but I had hoped > to > >> >> have a > >> >> > solution that didn't stop the whole system while I fixed it. > >> >> > > >> >> > To Drew: > >> >> > I think you were quite right when you spoke about planning the file > >> >> system. > >> >> > I've come to realize that my question is somewhat naive. One simply > >> >> doesn't > >> >> > do what I wanted to exactly because there is no easy way to > dismantle > >> >> > it. > >> >> It > >> >> > would be better to partition off some part of the OS drive and add > >> that > >> >> to a > >> >> > new volume group (or a new logical volume group) and mount that > under > >> >> > "/mnt", and then add whatever partitions on new drives to that > >> >> > logical > >> >> > volume. That logical volume could be dismounted and worked on, > >> >> > whereas > >> >> > whatever is under root cannot be worked on easily. > >> >> > >> >> > >> >> Lou, > >> >> > >> >> I'm surprised that you haven't yet been told that one of the first > >> >> rules > >> >> of > >> >> LVM is "don't use it for root!" Actually, I don't really hold with > >> that, > >> >> but it is MUCH more important to plan what you are doing when you do > >> have > >> >> an > >> >> LVM root partition. As you have found, you can not manipulate an LVM > >> >> partition while it is mounted. ( I know, there are ways for certain > >> types > >> >> of > >> >> filesystems, but in general, the rule holds. ) That is especially > true > >> >> when > >> >> the partition that you want to manipulate is root ( / ). > >> >> > >> >> My general practice is to set up the following list of Logical > Volumes > >> >> ( > >> >> the minimum which serves for most general purpose machines ): root, > >> swap, > >> >> home, usr, var. I generally allocate somewhere around 1G for the > root > >> >> partition. The others are sized appropriately for the environment. > >> That > >> >> usually leaves me a lot of free space on modern drives for "data" > >> >> space. > >> >> > >> >> The recommendation that you should find a LiveCD at this point is > >> probably > >> >> one that you should respect. Playing with mounted filesystems, > >> >> particularly > >> >> root, can rapidly lead you down a very nasty path. > >> >> > >> >> > >> >> Brian > >> >> > >> >> _______________________________________________ > >> >> linux-lvm mailing list > >> >> linux-lvm@redhat.com > >> >> https://www.redhat.com/mailman/listinfo/linux-lvm > >> >> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ > >> >> > >> > > >> > >> _______________________________________________ > >> linux-lvm mailing list > >> linux-lvm@redhat.com > >> https://www.redhat.com/mailman/listinfo/linux-lvm > >> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ > >> > > > > _______________________________________________ > linux-lvm mailing list > linux-lvm@redhat.com > https://www.redhat.com/mailman/listinfo/linux-lvm > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ > --001636c926cd6f98280476b4e8e7 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
Brem,
I agree. I thought it should be possible. Perhaps someone else can try= it and let us know in a future blog. I just don't have enough experien= ce to take it farther.
=A0
Regards,
Lou.
=A0
On Sat, Oct 24, 2009 at 1:54 PM, brem belguebli = <brem.belg= uebli@gmail.com> wrote:
Hi Lou,

Who is talking ab= out unmounting root ?

I'm just saying shrinking should be possib= le online as long as some
conditions are met (FS usage less than X %, reduced fragmentation ...)
<= br>Of course, this kind of procedure requiring a max of caution because
= of the high risk of data loss, I'm not sure it'll get implemented i= n
the current tools.



2009/10/24, Lou Arnold <larnolda1@gmail.com>:
> Hahaha. Brem, you= and I think alike. If you can do it let me know. I don't
> think= people can think of a way to keep the system on-line and yet dismount
> root so that LVM commands can work on it. If you can make it work, I&#= 39;ll buy
> you a virtual beer.
> Regards,
> Lou.
>=
> On Sat, Oct 24, 2009 at 10:04 AM, brem belguebli
> <brem.belguebli@gmail.com>wrot= e:
>
>> It's non sense arguing that LVM is not intended for ro= ot due to the
>> fact that you cannot shrink it =A0(growing online= is operational and
>> works fine).
>>
>> This i= s the only thing that is not allowed, though technically could
>> it be possible.
>>
>>
>>
>> 20= 09/10/24, Lou Arnold <larnolda1@g= mail.com>:
>> =A0> Haha, Yes, it would have been nice fo= r someone to have told me about
>> LVM and
>> > root. It would have saved literally days = of time. But my work is
>> > experimental and never with produc= tion system. In any case, now I know
>> > better.
>> &= gt;
>> > As for the LiveCD suggestion, I did not intend to discount it= . I had in
>> fact
>> > tried it several times, but wi= th =A0some success. It probably just a
>> > matter
>> = of
>> > finger problems for the failures. But I truly expected a grac= eful
>> > dismantling process without the need of shutting down= the system.
>> >
>> > This was in fact a good expe= rience. When you have to dig into things to
>> > understand why something works or doesn't work, you are a= lways luckier
>> than
>> > if things go perfectly righ= t from the beginning.
>> >
>> > Thanks to everyone = for your help.
>> > Lou.
>> >
>> >
>> >
&g= t;> > On Fri, Oct 23, 2009 at 5:06 PM, Brian McCullough <bdmc@bdmcc-us.com>
>> wrote:<= br> >> >
>> >> On Fri, Oct 23, 2009 at 01:41:23PM -0700= , Lou Arnold wrote:
>> >> > Ryan, Thanks for your suggest= ion. I know it works, but I had hoped to
>> >> have a
>> >> > solution that didn't stop the whole system while= I fixed it.
>> >> >
>> >> > To Drew:>> >> > I think you were quite right when you spoke about = planning the file
>> >> system.
>> >> > I've come to realiz= e that my question is somewhat naive. One simply
>> >> doesn= 't
>> >> > do what I wanted to exactly because there = is no easy way to dismantle
>> >> > it.
>> >> It
>> >> >= ; would be better to partition off some part of the OS drive and add
>= ;> that
>> >> to a
>> >> > new volume g= roup (or a new logical volume group) and mount that under
>> >> > "/mnt", and then add whatever partitions o= n new drives to that
>> >> > logical
>> >>= > volume. That logical volume could be dismounted and worked on,
>> >> > whereas
>> >> > whatever is under = root cannot be worked on easily.
>> >>
>> >><= br>>> >> Lou,
>> >>
>> >> I'm= surprised that you haven't yet been told that one of the first
>> >> rules
>> >> of
>> >> LVM is= "don't use it for root!" =A0Actually, I don't really hol= d with
>> that,
>> >> but it is MUCH more important= to plan what you are doing when you do
>> have
>> >> an
>> >> LVM root partiti= on. =A0As you have found, you can not manipulate an LVM
>> >>= ; partition while it is mounted. ( I know, there are ways for certain
>> types
>> >> of
>> >> filesystems, bu= t in general, the rule holds. ) =A0That is especially true
>> >= > when
>> >> the partition that you want to manipulate is= root ( / ).
>> >>
>> >> My general practice is to set up the= following list of Logical Volumes
>> >> (
>> >&= gt; the minimum which serves for most general purpose machines ): root,
>> swap,
>> >> home, usr, var. =A0I generally allocate= somewhere around 1G for the root
>> >> partition. =A0The ot= hers are sized appropriately for the environment.
>> =A0That
&g= t;> >> usually leaves me a lot of free space on modern drives for = "data"
>> >> space.
>> >>
>> >> The reco= mmendation that you should find a LiveCD at this point is
>> proba= bly
>> >> one that you should respect. =A0Playing with mount= ed filesystems,
>> >> particularly
>> >> root, can rapidly lead = you down a very nasty path.
>> >>
>> >>
&g= t;> >> Brian
>> >>
>> >> ___________= ____________________________________
>> >> linux-lvm mailing list
>> >> linux-lvm@redhat.com
>> >> https://www.redhat.com/mailman/listinfo/linux-lvm
>> >> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>&g= t; >>
>> >
>>
>> ______________________= _________________________
>> linux-lvm mailing list
>> linux-lvm@redhat.com
>> https://www.redhat.com/m= ailman/listinfo/linux-lvm
>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>
>= ;

_______________________________________________
linux-lvm maili= ng list
linux-lvm@redhat.com
ht= tps://www.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO = at http://tl= dp.org/HOWTO/LVM-HOWTO/

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