[linux-lvm] lvdisplay disagrees with df for resized LV

[linux-lvm] lvdisplay disagrees with df for resized LV

[Andy Cowling]

I'm just starting out using LVM under SuSE 7.0. I created a logical
volume which was initially 30Gb but I then resized it to 90Gb (using
lvresize) spanning 3 physical volumes each of 30Gb.

Now, lvdisplay/vgdisplay shows the LV/VG size as 90Gb, but df still
lists the file system as 30Gb.

How can I get df to recognise the addtional space ?

Thanks in advance
-- 
Andy Cowling
Red Eye International
http://www.redeye.com/

root@lynx:/opt/oracle > df -h /lv01
Filesystem            Size  Used Avail Use% Mounted on
/dev/vg01/lv01         30G   17G   13G  58% /lv01

root@lynx:/opt/oracle > lvdisplay  /dev/vg01/lv01
--- Logical volume ---
LV Name               /dev/vg01/lv01
VG Name               vg01
LV Write Access       read/write
LV Status             available
LV #                  1
# open                1
LV Size               90 GB
Current LE            23040
Allocated LE          23040
Allocation            next free
Read ahead sectors    128
Block device          58:0

root@lynx:/opt/oracle > vgdisplay  vg01          
--- Volume group ---
VG Name               vg01
VG Access             read/write
VG Status             available/resizable
VG #                  0
MAX LV                256
Cur LV                1
Open LV               1
MAX LV Size           255.99 GB
Max PV                256
Cur PV                3
Act PV                3
VG Size               90.01 GB
PE Size               4 MB
Total PE              23043
Alloc PE / Size       23040 / 90 GB
Free  PE / Size       3 / 12 MB

root@lynx:/opt/oracle > pvdisplay /dev/sdc5
--- Physical volume ---
PV Name               /dev/sdc5
VG Name               vg01
PV Size               30.01 GB / NOT usable 1.85 MB [LVM: 260 KB]
PV#                   3
PV Status             available
Allocatable           yes
Cur LV                1
PE Size (KByte)       4096
Total PE              7681
Free PE               3
Allocated PE          7678


root@lynx:/opt/oracle > pvdisplay /dev/sdd5
--- Physical volume ---
PV Name               /dev/sdd5
VG Name               vg01
PV Size               30.01 GB / NOT usable 1.85 MB [LVM: 260 KB]
PV#                   2
PV Status             available
Allocatable           yes (but full)
Cur LV                1
PE Size (KByte)       4096
Total PE              7681
Free PE               0
Allocated PE          7681


root@lynx:/opt/oracle > pvdisplay /dev/sde5
--- Physical volume ---
PV Name               /dev/sde5
VG Name               vg01
PV Size               30.01 GB / NOT usable 1.85 MB [LVM: 260 KB]
PV#                   1
PV Status             available
Allocatable           yes (but full)
Cur LV                1
PE Size (KByte)       4096
Total PE              7681
Free PE               0
Allocated PE          7681

Re: [linux-lvm] lvdisplay disagrees with df for resized LV

[Eric M. Hopper]

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On Wed, Oct 11, 2000 at 01:25:50PM +0100, Andy Cowling wrote:
> I'm just starting out using LVM under SuSE 7.0. I created a logical
> volume which was initially 30Gb but I then resized it to 90Gb (using
> lvresize) spanning 3 physical volumes each of 30Gb.
> 
> Now, lvdisplay/vgdisplay shows the LV/VG size as 90Gb, but df still
> lists the file system as 30Gb.
> 
> How can I get df to recognise the addtional space ?

	I'm assume the filesystem is an ext2 filesystem.  If it is, then
you need to find an ext2 resizing utility.  resize2fs is one such
utility.  I'm not sure where to find them on the web, but they
definitely exist.

	In general, the filesystem can only be resized when it's
offline.  The filesystem resizing utility updates all the filesystem
data structures to reflect the new size, and creates new data structures
in the new space.  df bases it's output on what the filesystem says
about the size, not the block device itself.

	It might be that SUSE came with a resizing utility.  I'd
actually rather expect it if they also packaged LVM.

Have fun (if at all possible),
-- 
The best we can hope for concerning the people at large is that they
be properly armed.  -- Alexander Hamilton
-- Eric Hopper (hopper@omnifarious.mn.org http://www.omnifarious.org/~hopper) --

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Re: [linux-lvm] lvdisplay disagrees with df for resized LV

[Andy Cowling]

Thanks to all for your help. I'm using reiserfs and on SuSE 7.0, the
resize utility was hidden away in /sbin/resize_reiserfs.

I have resized the file system to 90G successfully but, there always a
but isn't there :-), df now reports a total of 88Gb.

Out of interest is this due to rounding or reisfer/LVM housekeeping ?

# umount /lv01
# resize_reiserfs -s90000M /dev/vg01/lv01
ReiserFS report:
blocksize             4096
block count           23040000 (7864320)
free blocks           18466724 (3291508)
bitmap block count    704 (240)

Syncing..done
# mount /lv01
# df -h /lv01
Filesystem            Size  Used Avail Use% Mounted on
/dev/vg01/lv01         88G   17G   70G  20% /lv01

PS. In case you're wondering what I did to deserve such a high-powered
workstation, this m/c is a 4 proc, 2Gb RAM Dell PowerEdge 6400 server
running an Oracle 8 data warehouse.

Re: [linux-lvm] lvdisplay disagrees with df for resized LV

[Eric M. Hopper]

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On Wed, Oct 11, 2000 at 05:28:22PM +0100, Andy Cowling wrote:
> Thanks to all for your help. I'm using reiserfs and on SuSE 7.0, the
> resize utility was hidden away in /sbin/resize_reiserfs.
> 
> I have resized the file system to 90G successfully but, there always a
> but isn't there :-), df now reports a total of 88Gb.
> 
> Out of interest is this due to rounding or reisfer/LVM housekeeping ?

	It's due to Resierfs housekeeping.  That represents a 2.2%
overhead, for filesystem housekeeping, which isn't too bad.  I'm a
little surprised it's that large.  I wouldn't be if it were ext2, and
would actually expect it to be more, but it's certainly within the realm
of reasonableness.

Have fun (if at all possible),
-- 
The best we can hope for concerning the people at large is that they
be properly armed.  -- Alexander Hamilton
-- Eric Hopper (hopper@omnifarious.mn.org http://www.omnifarious.org/~hopper) --

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Re: [linux-lvm] lvdisplay disagrees with df for resized LV

[Charles Duffy]

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On Wed, Oct 11, 2000 at 05:28:22PM +0100, Andy Cowling wrote:
> Thanks to all for your help. I'm using reiserfs and on SuSE 7.0, the
> resize utility was hidden away in /sbin/resize_reiserfs.
> 
> I have resized the file system to 90G successfully but, there always a
> but isn't there :-), df now reports a total of 88Gb.
> 
> Out of interest is this due to rounding or reisfer/LVM housekeeping ?

FYI, reiserfs can also be resized online (at least, the current
2.4-beta versions) w/ a command like the following:

mount -o remount,resize=[NEWSIZE] filesystem

I can't speak authoritatively about the missing 2G, but you can
compare the LVM's allocated size (use vgdisplay to see how many PEs
are allocated and what their size is) to the size of the filesystem
reported by debugreiserfs.

Also note that some earlier versions of reiserfs had some issues which
resulted in inaccurate results from du; however, I don't know of any
issues offhand which affected df's results.

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Re: [linux-lvm] lvdisplay disagrees with df for resized LV

[Brian Poole]

> I have resized the file system to 90G successfully but, there always a
> but isn't there :-), df now reports a total of 88Gb.
>
> Out of interest is this due to rounding or reisfer/LVM housekeeping ?

Neither, this is actually a misperception of what a Gb really is. A Gb is
_not_ 1000Mb, despite what harddrive manufacturers will gladly tell you,
it is 1024Mb, and a Mb is really 1024Kb, and so on.

Taking a look at your particular case, 90,000 Mb divided by 1024 (not
1000, so it isn't 90) to get Gbs is 87.89G, which is indeed exactly what
you have, no?


-b

Re: [linux-lvm] lvdisplay disagrees with df for resized LV

[Andreas Dilger]

Eric M. Hopper writes:
> On Wed, Oct 11, 2000 at 01:25:50PM +0100, Andy Cowling wrote:
> > I'm just starting out using LVM under SuSE 7.0. I created a logical
> > volume which was initially 30Gb but I then resized it to 90Gb (using
> > lvresize) spanning 3 physical volumes each of 30Gb.
> >
> > Now, lvdisplay/vgdisplay shows the LV/VG size as 90Gb, but df still
> > lists the file system as 30Gb.
> >
> > How can I get df to recognise the addtional space ?
> 
> 	I'm assume the filesystem is an ext2 filesystem.  If it is, then
> you need to find an ext2 resizing utility.  resize2fs is one such
> utility.  I'm not sure where to find them on the web, but they
> definitely exist.

You can get ext2 resizing tools from ext2resize.sourceforge.net.  There
is also the resize2fs tool included with e2fsprogs 1.19.

> 	In general, the filesystem can only be resized when it's
> offline.  The filesystem resizing utility updates all the filesystem
> data structures to reflect the new size, and creates new data structures
> in the new space.

With the ext2online kernel patch and user-space tool, you can do online
(mounted) ext2 resizes.

Cheers, Andreas

Re: [linux-lvm] lvdisplay disagrees with df for resized LV

[Les Hazelton]

Andy,

The size of the LV and the size of the filesystem are two different
things.  I have always found that after increasing the size of the LV I
still needed to resize the filesystem. Depending on what filesystem you
are using, look at /sbin/resize_reiserfs or /usr/sbin/ext2resize.  That
should provide the result you are looking for.

Andy Cowling wrote:
> 
> I'm just starting out using LVM under SuSE 7.0. I created a logical
> volume which was initially 30Gb but I then resized it to 90Gb (using
> lvresize) spanning 3 physical volumes each of 30Gb.
> 
> Now, lvdisplay/vgdisplay shows the LV/VG size as 90Gb, but df still
> lists the file system as 30Gb.
> 
> How can I get df to recognise the addtional space ?
> 
> Thanks in advance
> --
> Andy Cowling
> Red Eye International
> http://www.redeye.com/
> 
> root@lynx:/opt/oracle > df -h /lv01
> Filesystem            Size  Used Avail Use% Mounted on
> /dev/vg01/lv01         30G   17G   13G  58% /lv01
> 
> root@lynx:/opt/oracle > lvdisplay  /dev/vg01/lv01
> --- Logical volume ---
> LV Name               /dev/vg01/lv01
> VG Name               vg01
> LV Write Access       read/write
> LV Status             available
> LV #                  1
> # open                1
> LV Size               90 GB
> Current LE            23040
> Allocated LE          23040
> Allocation            next free
> Read ahead sectors    128
> Block device          58:0
> 
> root@lynx:/opt/oracle > vgdisplay  vg01
> --- Volume group ---
> VG Name               vg01
> VG Access             read/write
> VG Status             available/resizable
> VG #                  0
> MAX LV                256
> Cur LV                1
> Open LV               1
> MAX LV Size           255.99 GB
> Max PV                256
> Cur PV                3
> Act PV                3
> VG Size               90.01 GB
> PE Size               4 MB
> Total PE              23043
> Alloc PE / Size       23040 / 90 GB
> Free  PE / Size       3 / 12 MB
> 
> root@lynx:/opt/oracle > pvdisplay /dev/sdc5
> --- Physical volume ---
> PV Name               /dev/sdc5
> VG Name               vg01
> PV Size               30.01 GB / NOT usable 1.85 MB [LVM: 260 KB]
> PV#                   3
> PV Status             available
> Allocatable           yes
> Cur LV                1
> PE Size (KByte)       4096
> Total PE              7681
> Free PE               3
> Allocated PE          7678
> 
> root@lynx:/opt/oracle > pvdisplay /dev/sdd5
> --- Physical volume ---
> PV Name               /dev/sdd5
> VG Name               vg01
> PV Size               30.01 GB / NOT usable 1.85 MB [LVM: 260 KB]
> PV#                   2
> PV Status             available
> Allocatable           yes (but full)
> Cur LV                1
> PE Size (KByte)       4096
> Total PE              7681
> Free PE               0
> Allocated PE          7681
> 
> root@lynx:/opt/oracle > pvdisplay /dev/sde5
> --- Physical volume ---
> PV Name               /dev/sde5
> VG Name               vg01
> PV Size               30.01 GB / NOT usable 1.85 MB [LVM: 260 KB]
> PV#                   1
> PV Status             available
> Allocatable           yes (but full)
> Cur LV                1
> PE Size (KByte)       4096
> Total PE              7681
> Free PE               0
> Allocated PE          7681

-- 

Good Journey, longevity and prosperity to all

Les Hazelton

RE: [linux-lvm] lvdisplay disagrees with df for resized LV

[Rochelle Lakey]

Hello Andy,

My guess would be that you have to resize the filesystem as well.
Hope that helps.

Rochelle Lakey

-----Original Message-----
From: Andy Cowling [mailto:andy@redeye.com]
Sent: Wednesday, October 11, 2000 5:26 AM
To: linux-lvm@msede.com
Cc: Dan Garcia
Subject: [linux-lvm] lvdisplay disagrees with df for resized LV


I'm just starting out using LVM under SuSE 7.0. I created a logical
volume which was initially 30Gb but I then resized it to 90Gb (using
lvresize) spanning 3 physical volumes each of 30Gb.

Now, lvdisplay/vgdisplay shows the LV/VG size as 90Gb, but df still
lists the file system as 30Gb.

How can I get df to recognise the addtional space ?

Thanks in advance
-- 
Andy Cowling
Red Eye International
http://www.redeye.com/

root@lynx:/opt/oracle > df -h /lv01
Filesystem            Size  Used Avail Use% Mounted on
/dev/vg01/lv01         30G   17G   13G  58% /lv01

root@lynx:/opt/oracle > lvdisplay  /dev/vg01/lv01
--- Logical volume ---
LV Name               /dev/vg01/lv01
VG Name               vg01
LV Write Access       read/write
LV Status             available
LV #                  1
# open                1
LV Size               90 GB
Current LE            23040
Allocated LE          23040
Allocation            next free
Read ahead sectors    128
Block device          58:0

root@lynx:/opt/oracle > vgdisplay  vg01          
--- Volume group ---
VG Name               vg01
VG Access             read/write
VG Status             available/resizable
VG #                  0
MAX LV                256
Cur LV                1
Open LV               1
MAX LV Size           255.99 GB
Max PV                256
Cur PV                3
Act PV                3
VG Size               90.01 GB
PE Size               4 MB
Total PE              23043
Alloc PE / Size       23040 / 90 GB
Free  PE / Size       3 / 12 MB

root@lynx:/opt/oracle > pvdisplay /dev/sdc5
--- Physical volume ---
PV Name               /dev/sdc5
VG Name               vg01
PV Size               30.01 GB / NOT usable 1.85 MB [LVM: 260 KB]
PV#                   3
PV Status             available
Allocatable           yes
Cur LV                1
PE Size (KByte)       4096
Total PE              7681
Free PE               3
Allocated PE          7678


root@lynx:/opt/oracle > pvdisplay /dev/sdd5
--- Physical volume ---
PV Name               /dev/sdd5
VG Name               vg01
PV Size               30.01 GB / NOT usable 1.85 MB [LVM: 260 KB]
PV#                   2
PV Status             available
Allocatable           yes (but full)
Cur LV                1
PE Size (KByte)       4096
Total PE              7681
Free PE               0
Allocated PE          7681


root@lynx:/opt/oracle > pvdisplay /dev/sde5
--- Physical volume ---
PV Name               /dev/sde5
VG Name               vg01
PV Size               30.01 GB / NOT usable 1.85 MB [LVM: 260 KB]
PV#                   1
PV Status             available
Allocatable           yes (but full)
Cur LV                1
PE Size (KByte)       4096
Total PE              7681
Free PE               0
Allocated PE          7681

Re: [linux-lvm] lvdisplay disagrees with df for resized LV

[Holger Grothe]

Hello,
> 
> I have resized the file system to 90G successfully but, there always a
> but isn't there :-), df now reports a total of 88Gb.
> 
> Out of interest is this due to rounding or reisfer/LVM housekeeping ?
> 
neither nor :-).

> # umount /lv01
> # resize_reiserfs -s90000M /dev/vg01/lv01

resize_reiserfs did what you said. But 90000MB is not equal to 90GB
The standard power for the transfer K->M->G is 1024 (most tools) and 
not 1000 (==> 92160MB = 90 GB).

Compare the difference of 'df -h' ("real GB") and 'df -H' ("marketing GB").

Regards, Holger
--
Holger Grothe  (Email: grothe@mathematik.tu-darmstadt.de)
Fachbereich Mathematik, TU Darmstadt