Shawn Everett wrote:
On Sunday 14 October 2007, Michael Kress wrote:
I can mount them and work with them, no prob. Now I'd like to have my 25
files of 4GB file size each coherently mounted as one 100G drive. Is
this possible? Must be something like Raid 0.
TIA Michael
You might try something like this:
http://osdir.com/ml/linux.lvm.general/2003-10/msg00096.html
Personally I think it's a bad idea. :)
Shawn
Hi, I dont't like it either, but I have to adopt to the given facts. :-(
Your proposed method seems to be yet elegant.
Anyways, I got a problem with it.
This is what I do:
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dd if=/dev/zero of=fake-disk-1.img bs=1M count=10
dd if=/dev/zero of=fake-disk-2.img bs=1M count=10
losetup /dev/loop0 fake-disk-1.img
losetup /dev/loop1 fake-disk-2.img
pvcreate /dev/loop0
pvcreate /dev/loop1
vgcreate /dev/vgtest /dev/loop0 /dev/loop1
root@x05:/root [0] > vgs
VG #PV #LV #SN Attr VSize VFree
vgtest 2 0 0 wz--n- 16.00M 16.00M
lvcreate --size=16M --name=lvtest /dev/vgtest
mkfs /dev/vgtest/lvtest
mkdir /mnt/lvtest
mount /dev/vgtest/lvtest /mnt/lvtest/
root@x05:/root [0] > df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 3.0G 2.4G 617M 80% /
none 256M 0 256M 0% /dev/shm
/dev/mapper/vgtest-lvtest
16M 140K 15M 1% /mnt/lvtest
umount /mnt/lvtest/
shutdown -r now
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So far so good.
After reboot I found this:
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root@x05:/root [0] > lvs
No volume groups found
root@x05:/root [0] > vgs
No volume groups found
root@x05:/root [0] > pvs
(no output)
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So I tried to recover the 2 files: I had to 'losetup' the files again,
but pvcreate hangs here:
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root@x05:/root [0] > pvcreate /dev/loop0
Can't initialize physical volume "/dev/loop0" of volume group "vgtest"
without -ff
root@x05:/root [5] >
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So I did:
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root@x05:/root [5] > pvcreate -ff /dev/loop0
Really INITIALIZE physical volume "/dev/loop0" of volume group "vgtest"
[y/n]? y
WARNING: Forcing physical volume creation on /dev/loop0 of volume
group "vgtest"
Physical volume "/dev/loop0" successfully created
root@x05:/root [0] > pvcreate -ff /dev/loop1
Couldn't find device with uuid 'Z4Dr2Q-CBeM-QDHP-26d2-O1GV-DgZh-C7Z6pK'.
Couldn't find all physical volumes for volume group vgtest.
Couldn't find device with uuid 'Z4Dr2Q-CBeM-QDHP-26d2-O1GV-DgZh-C7Z6pK'.
Couldn't find all physical volumes for volume group vgtest.
get_pv_from_vg_by_id: vg_read failed to read VG vgtest
Physical volume "/dev/loop1" successfully created
root@x05:/root [0] > vgcreate /dev/vgtest /dev/loop0 /dev/loop1
Volume group "vgtest" successfully created
root@x05:/root [0] > lvcreate --size=16M --name=lvtest /dev/vgtest
Logical volume "lvtest" created
root@x05:/root [0] > mount /dev/vgtest/lvtest /mnt/lvtest/
mount: you must specify the filesystem type
root@x05:/root [32] > fsck /dev/vgtest/lvtest
fsck 1.35 (28-Feb-2004)
e2fsck 1.35 (28-Feb-2004)
Couldn't find ext2 superblock, trying backup blocks...
Resize inode not valid. Recreate<y>? yes
/dev/vgtest/lvtest was not cleanly unmounted, check forced.
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
Free blocks count wrong for group #0 (7854, counted=7855).
Fix<y>? yes
Free blocks count wrong (15722, counted=15723).
Fix<y>? yes
/dev/vgtest/lvtest: ***** FILE SYSTEM WAS MODIFIED *****
/dev/vgtest/lvtest: 11/4096 files (0.0% non-contiguous), 661/16384 blocks
root@x05:/root [1] > mount /dev/vgtest/lvtest /mnt/lvtest/
root@x05:/root [0] >
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Ok, this works, but I can't rely on such a file system. Any idea on how
I could get back the original logical volume lvtest without the indeed
ugly file system check and without endangering the data contained in the lv?
TIA
Michael
--
Michael Kress, kress@xxxxxxxxxxx
http://www.michael-kress.de / http://kress.net
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