Hey guys,
My experience with logical volume managers (lvms) is limited. I've often added drives and extended them at work using cloud VMs, but beyond that I've never had to resize, remove or really "manage" them (just delete VM when I'm done with it
)
I have a home server running CentOS 6. I set up an LVM when I first built it but as a less-informed Linuxer at the time and just want to see what you guys think of the setup and if it should be changed. I'm looking into it more now as I just bought a 4 TB HDD I want to add.
Current Disks:
/dev/sda - 64 GB SSD - assigned to lv_root (supposedly for /, but also has boot sector)
/dev/sdb - 2 TB HDD - assigned to lv_home (supposedly for /home)
Adding a 4 TB HDD to extend /home dirs.
My VG/PV/LV and df -h output is below:
vgdisplay:
pvdisplay:
lvdisplay:
df -h:
I wanted to check a few things:
1. I've heard its not a good idea to set up an LVM for disks at different r/w speeds. Is it a better idea not to have SSD and HDDs on the same LVM?
2. Ideally I want root (/) on the SSD and /home on the HDDs. According to df -h that looks like it is correct, but can I trust df -h with an LVM? Since I wouldn't think they are directly 'mounted'.
3. I also noticed there is a swap logical volume but can't really tell what disk it was created with. Is there a command to check?
4. I'm thinking of upgrading the OS to Centos 7 since 6 is quickly reaching EOL, maybe even doing a fresh install so I can use disk encryption. Is there a good way or resource anyone has on the best way to "break up" an LVM? I'd be worried of file corruption on files that extend to multiple physical disks but maybe this isn't a problem since each disk is part of its own logical volume?
Sorry in advance for the barrage of info and questions. Really also just looking for general advice on if and how others have set up LVMs, particularly with different disk types.
Thanks!
Mike
My experience with logical volume managers (lvms) is limited. I've often added drives and extended them at work using cloud VMs, but beyond that I've never had to resize, remove or really "manage" them (just delete VM when I'm done with it
) I have a home server running CentOS 6. I set up an LVM when I first built it but as a less-informed Linuxer at the time and just want to see what you guys think of the setup and if it should be changed. I'm looking into it more now as I just bought a 4 TB HDD I want to add.
Current Disks:
/dev/sda - 64 GB SSD - assigned to lv_root (supposedly for /, but also has boot sector)
/dev/sdb - 2 TB HDD - assigned to lv_home (supposedly for /home)
Adding a 4 TB HDD to extend /home dirs.
My VG/PV/LV and df -h output is below:
vgdisplay:
Code:
--- Volume group ---
VG Name vg_charlie
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 7
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 3
Open LV 3
Max PV 0
Cur PV 2
Act PV 2
VG Size 1.88 TiB
PE Size 4.00 MiB
Total PE 492070
Alloc PE / Size 491923 / 1.88 TiB
Free PE / Size 147 / 588.00 MiB
VG UUID 89FdWQ-xFkj-oTLQ-r93N-SR5N-oCk1-a04klFpvdisplay:
Code:
[root@charlie: /dev/vg_charlie]# pvdisplay
--- Physical volume ---
PV Name /dev/sda2
VG Name vg_charlie
PV Size 59.14 GiB / not usable 4.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 15138
Free PE 0
Allocated PE 15138
PV UUID XvQPeA-IZCU-Bz4o-Ok1d-JtZn-vjYr-mIDGy6
--- Physical volume ---
PV Name /dev/sdb
VG Name vg_charlie
PV Size 1.82 TiB / not usable 1.09 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 476932
Free PE 147
Allocated PE 476785
PV UUID bxJTA5-h0Me-ahUK-EP7H-Hxvk-U0YG-Yc8lDIlvdisplay:
Code:
[root@charlie: /dev/vg_charlie]# lvdisplay
--- Logical volume ---
LV Path /dev/vg_charlie/lv_root
LV Name lv_root
VG Name vg_charlie
LV UUID GizFrC-I1Lw-3hjF-iUMd-bvWc-Ez09-0DYyn6
LV Write Access read/write
LV Creation host, time charlie, 2014-07-29 17:56:22 -0400
LV Status available
# open 1
LV Size 48.45 GiB
Current LE 12402
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
--- Logical volume ---
LV Path /dev/vg_charlie/lv_home
LV Name lv_home
VG Name vg_charlie
LV UUID 4dJHsn-dDLn-ya4q-0IFC-1nRK-s2yi-ulUUpc
LV Write Access read/write
LV Creation host, time charlie, 2014-07-29 17:56:43 -0400
LV Status available
# open 1
LV Size 1.82 TiB
Current LE 477995
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:2
--- Logical volume ---
LV Path /dev/vg_charlie/lv_swap
LV Name lv_swap
VG Name vg_charlie
LV UUID njaAy6-ef9w-t9pi-dFxF-tNH8-Ja4b-Qyhi2e
LV Write Access read/write
LV Creation host, time charlie, 2014-07-29 17:56:46 -0400
LV Status available
# open 1
LV Size 5.96 GiB
Current LE 1526
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1df -h:
Code:
[root@charlie: /dev/vg_charlie]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_charlie-lv_root
48G 5.1G 41G 12% /
tmpfs 3.8G 164K 3.8G 1% /dev/shm
/dev/sda1 477M 169M 283M 38% /boot
/dev/mapper/vg_charlie-lv_home
1.8T 1.5T 262G 86% /homeI wanted to check a few things:
1. I've heard its not a good idea to set up an LVM for disks at different r/w speeds. Is it a better idea not to have SSD and HDDs on the same LVM?
2. Ideally I want root (/) on the SSD and /home on the HDDs. According to df -h that looks like it is correct, but can I trust df -h with an LVM? Since I wouldn't think they are directly 'mounted'.
3. I also noticed there is a swap logical volume but can't really tell what disk it was created with. Is there a command to check?
4. I'm thinking of upgrading the OS to Centos 7 since 6 is quickly reaching EOL, maybe even doing a fresh install so I can use disk encryption. Is there a good way or resource anyone has on the best way to "break up" an LVM? I'd be worried of file corruption on files that extend to multiple physical disks but maybe this isn't a problem since each disk is part of its own logical volume?
Sorry in advance for the barrage of info and questions
. Really also just looking for general advice on if and how others have set up LVMs, particularly with different disk types.Thanks!
Mike
