ryan80
asked on
how to tell if a server boots from SAN
I have a Fedora server that I believe boots from a SAN. However how can I tell for sure if this is the case from the server itself. how would I go about doing this? here is some information about the drives.
fdisk -l
Disk /dev/sda: 250.0 GB, 250000000000 bytes
255 heads, 63 sectors/track, 30394 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 30394 244035382+ 8e Linux LVM
mount
/dev/mapper/VolGroup00-Log Vol00 on / type ext3 (rw)
lvdisplay
--- Logical volume ---
LV Name /dev/VolGroup00/LogVol00
VG Name VolGroup00
LV UUID fs7sUC-4KNe-Zz54-YozX-GDux -PQpC-vBhY KY
LV Write Access read/write
LV Status available
# open 1
LV Size 225.00 GB
Current LE 7200
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
--- Logical volume ---
LV Name /dev/VolGroup00/LogVol01
VG Name VolGroup00
LV UUID lZ4XP1-ZdON-vZCW-lxxv-pjyK -Tinq-mbM1 Bv
LV Write Access read/write
LV Status available
# open 1
LV Size 7.69 GB
Current LE 246
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1
pvdisplay
--- Physical volume ---
PV Name /dev/sda2
VG Name VolGroup00
PV Size 232.73 GB / not usable 11.80 MB
Allocatable yes
PE Size (KByte) 32768
Total PE 7447
Free PE 1
Allocated PE 7446
PV UUID jeXX7v-k7Ll-DoP7-ZJ6M-S0Ad -z41X-ukgS hr
fdisk -l
Disk /dev/sda: 250.0 GB, 250000000000 bytes
255 heads, 63 sectors/track, 30394 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 30394 244035382+ 8e Linux LVM
mount
/dev/mapper/VolGroup00-Log
lvdisplay
--- Logical volume ---
LV Name /dev/VolGroup00/LogVol00
VG Name VolGroup00
LV UUID fs7sUC-4KNe-Zz54-YozX-GDux
LV Write Access read/write
LV Status available
# open 1
LV Size 225.00 GB
Current LE 7200
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
--- Logical volume ---
LV Name /dev/VolGroup00/LogVol01
VG Name VolGroup00
LV UUID lZ4XP1-ZdON-vZCW-lxxv-pjyK
LV Write Access read/write
LV Status available
# open 1
LV Size 7.69 GB
Current LE 246
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1
pvdisplay
--- Physical volume ---
PV Name /dev/sda2
VG Name VolGroup00
PV Size 232.73 GB / not usable 11.80 MB
Allocatable yes
PE Size (KByte) 32768
Total PE 7447
Free PE 1
Allocated PE 7446
PV UUID jeXX7v-k7Ll-DoP7-ZJ6M-S0Ad
From what I can see, I don't see any SAN.
All what I see is logical volume. It is probably booting from /dev/sda2 which contains your logical volume.
All what I see is logical volume. It is probably booting from /dev/sda2 which contains your logical volume.
If you look carefully, your physical volume is based entirely on your /dev/sda2, which is your SCSI drive, and is local to your computer. Your volume group is based entirely on this physical volume, nothing else.
ASKER
df -hT /boot
Filesystem Type Size Used Avail Use% Mounted on
/dev/sda1 ext3 99M 15M 80M 16% /boot
Filesystem Type Size Used Avail Use% Mounted on
/dev/sda1 ext3 99M 15M 80M 16% /boot
ASKER
There is a system in place here, Cobbler, that is used for making PXE boot configs.
I see the IP address of this server in the Cobbler system, but there is no mac address configured which I thought would be neccesary for PXE boot to work.
Now if a system uses PXE boot, does that mean that the OS will be located on the network? or can it be used just to install an OS onto the local drive(s)?
I see the IP address of this server in the Cobbler system, but there is no mac address configured which I thought would be neccesary for PXE boot to work.
Now if a system uses PXE boot, does that mean that the OS will be located on the network? or can it be used just to install an OS onto the local drive(s)?
So your system is getting booted from /dev/sda1, which is local to your system and is the correct way to do it. We don't recommend putting /boot even on the LVM. It is a bad practice but still very senior admins do it.
Yes, that is the idea behind the PXE boot. You can install your systems over the network. So there are numerous technologies that run behind the scene. What kind of OS is it?
For stage1 boot phase, tftp is used using PXE, and for stage 2 boot, ftp, nfs, http may be used.
For stage1 boot phase, tftp is used using PXE, and for stage 2 boot, ftp, nfs, http may be used.
ASKER
It is Fedora 9
For Fedora, I believe you should be using PXE and then Kickstart mechanism. This part is different for all OSs. Redhat family goes by kickstart which is very powerful mechanism for doing a custom install.
This should answer all your questions. Anything else?
This should answer all your questions. Anything else?
ASKER
Sorry I thought I had posted another post. Last one.
Is an sda always local? How do you actually tell that something is a network drive (whether nfs, fixer channel, iscsi)?
Is an sda always local? How do you actually tell that something is a network drive (whether nfs, fixer channel, iscsi)?
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ASKER
Thanks, that is what I thought.
the SAN is using fibre channel and there is a multi path driver that is installed to reach it. The device path shows as
/dev/mapper/mpath0p1
Thanks for your patience with walking me through this. i really appreciate it and have a much better grasp on this now.
the SAN is using fibre channel and there is a multi path driver that is installed to reach it. The device path shows as
/dev/mapper/mpath0p1
Thanks for your patience with walking me through this. i really appreciate it and have a much better grasp on this now.
df -hT /boot
I am interested to know where the /boot is located. That is where it boots from, at least the second stage of its booting. The first stage always takes place from the first 570 or sectors of the local drive