partition strategy
Hi,
This is my first post, so please bear with me.
I have 2 free disk areas 230G and 231G. I hoping to take advantage of RAID-0.
Is it better to create 3 partitions 2 x230G + 1G - create a striped LV over the first 2, then add the third to the volume group, then extend the LV over to the new 1G extension (since LVM2 allows extending striped lv-s). And if so, does the non-striped area get used as a last resort (after the striped area is completely full)?
OR
Is it better to create 2 paritions 230G and 231G, put both in a vg, create a striped lv and lvm will take care of striping to the 230G mark, then writing linearly afterwards.
TIA for any advice.
Best,
Arshavir
Quoted 12 lines · Arshavir Grigorian
Hi,
This is my first post, so please bear with me.
I have 2 free disk areas 230G and 231G. I hoping to take advantage of RAID-0.
Is it better to create 3 partitions 2 x230G + 1G - create a striped LV over the first 2, then add the third to the volume group, then extend the LV over to the new 1G extension (since LVM2 allows extending striped lv-s). And if so, does the non-striped area get used as a last resort (after the striped area is completely full)?
OR
Is it better to create 2 paritions 230G and 231G, put both in a vg, create a striped lv and lvm will take care of striping to the 230G mark, then writing linearly afterwards.
Quoted 8 lines
TIA for any advice.
Best,
Arshavir
Hi,
I mailed the above message about a week ago and there have not been any reponses.
I am wondering whether there is a development list where I might have a better chance of getting an answer to my question (the HOWTO page did not mention any dev lists, so I am not sure). Many thanks.
Arshavir
Quoted 8 lines · Arshavir Grigorian
Quoted 5 lines · Arshavir Grigorian
Is it better to create 3 partitions 2 x230G + 1G - create a striped LV over the first 2, then add the third to the volume group, then extend the LV over to the new 1G extension (since LVM2 allows extending striped lv-s). And if so, does the non-striped area get used as a last resort (after the striped area is completely full)?
I don't have the expertise to know for sure but that makes sense to me. I would just make 3 partitions -- you can always just save the 1GB partition for something else -- swap or a backup partition.
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Stephen
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Donna Smallin, "Unclutter Your Home"Quoted 3 lines · Arshavir Grigorian
Quoted 3 lines
Is it better to create 3 partitions 2 x230G + 1G
OR
Is it better to create 2 paritions 230G and 231G, put both in a vg,
The VG contains the same space in both cases so do the simplest ie the first option. In both cases you'll need to run lvcreate for 460G followed by lvextend for 1G.
Alasdair
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Quoted 8 lines · Alasdair G Kergon
Quoted 4 lines · Arshavir Grigorian
Quoted 4 lines
Is it better to create 3 partitions 2 x230G + 1G OR
Is it better to create 2 paritions 230G and 231G, put both in a vg,
Quoted 7 lines
The VG contains the same space in both cases so do the simplest ie the first option. In both cases you'll need to run lvcreate for 460G followed by lvextend for 1G.
Alasdair
Thanks for the response.
For some reason even the first option does not work.
I created 3 partitions, added the 2 same sized ones to a vg, created a striped lv, then extended the vg to include the third small partition. After this I tried extending the lv to the new partition, but got the error below. Could you, please tell me what I am doing wrong? TIA.
Arshavir
casals:~# vgdisplay --- Volume group --- VG Name vg00 System ID Format lvm2 Metadata Areas 2 Metadata Sequence No 2 VG Access read/write VG Status resizable MAX LV 0 Cur LV 0 Open LV 0 Max PV 0 Cur PV 2 Act PV 2 VG Size 463.60 GB PE Size 4.00 MB Total PE 118682 Alloc PE / Size 0 / 0 Free PE / Size 118682 / 463.60 GB VG UUID PyRda0-g9mC-LxrH-txvE-CKb6-jP6T-Ou103y
casals:~# lvcreate -i 2 -I 8 -l 118682 vg00
casals:~# vgextend vg00 /dev/hdc3 Volume group "vg00" successfully extended
casals:~# vgdisplay --- Volume group --- VG Name vg00 System ID Format lvm2 Metadata Areas 3 Metadata Sequence No 4 VG Access read/write VG Status resizable MAX LV 0 Cur LV 1 Open LV 0 Max PV 0 Cur PV 3 Act PV 3 VG Size 464.12 GB PE Size 4.00 MB Total PE 118816 Alloc PE / Size 118682 / 463.60 GB Free PE / Size 134 / 536.00 MB VG UUID PyRda0-g9mC-LxrH-txvE-CKb6-jP6T-Ou103y
casals:~# lvextend -l +134 /dev/vg00/lvol0 /dev/hdc3 Using stripesize of last segment 8KB Extending logical volume lvol0 to 464.12 GB Insufficient allocatable extents suitable for parallel use for logical volume lvol0: 118816 required
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Quoted 2 lines
Is it better to create 3 partitions 2 x230G + 1G
Is it better to create 2 paritions 230G and 231G, put both in a vg,ie the first option.
I meant the second option:-)
Quoted 6 lines
Could you, please tell me what I am doing wrong? TIA.
casals:~# lvextend -l +134 /dev/vg00/lvol0 /dev/hdc3 Using stripesize of last segment 8KB Insufficient allocatable extents suitable for parallel use for logical volume lvol0: 118816 required
If you don't specify the stripe settings, lvextend uses whatever the last segment of the LV you're extending uses i.e. 2 stripes in this case. So you need to specify -i1 to add a new segment with just one stripe.
Alasdair
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Quoted 25 lines · Alasdair G Kergon
Quoted 9 lines
Quoted 9 lines
Quoted 3 lines
Quoted 3 lines
Is it better to create 3 partitions 2 x230G + 1G Is it better to create 2 paritions 230G and 231G, put both in a vg,
ie the first option.
I meant the second option:-)
Quoted 11 lines
Could you, please tell me what I am doing wrong? TIA.
casals:~# lvextend -l +134 /dev/vg00/lvol0 /dev/hdc3 Using stripesize of last segment 8KB Insufficient allocatable extents suitable for parallel use for logical volume lvol0: 118816 required
Quoted 7 lines
If you don't specify the stripe settings, lvextend uses whatever
the last segment of the LV you're extending uses i.e. 2 stripes in this case. So you need to specify -i1 to add a new segment with just one stripe.Alasdair
Many thanks. It all makes sense now.
The way I got it working is just creating 2 partititions, getting the number of extends from the smaller partition, creating a striped lv with that paritition count, then extending it to the remaining the extents as with a single stripe.
Arshavir