Backup and snapshot location in linux partitions

[king_slavcho]

Hello everybody,

I wanted to ask you some things about the security gateways (we use checkpoint 6400) and i wanted to make a snapshot but i encountered an error that there was not enough space on the disk in order to make a snapshot..

Than i started to investigate how the partitions are done into RHEL and how to space is being made for the snapshot and found out that when a snapshot is being created a new partition is being made with the name of the snapshot.

Can someone explain me where does the space come from to create the new partition? Is there any free space in the LVM mapper and the partition is being created from it or?

I can see that the backup is done in the /var/log partition which is inside the LVM mapper which for me is ok and I understand it.

But the thing is that I can not understand where does the space come from for the snapshot partition.

Also I would like to understand the partitions from these commands because they differ very much:

With "fdisk -l" i see:

# Start End Size Type Name
1 34 614433 300M EFI System
Partition 1 does not start on physical sector boundary.
2 614434 66272088 31.3G Linux swap
Partition 2 does not start on physical sector boundary.
3 66272089 468862094 192G Linux LVM
Partition 3 does not start on physical sector boundary.

With "parted

Number Start End Size File system Name Flags
1 17.4kB 315MB 315MB ext3 boot
2 315MB 33.9GB 33.6GB linux-swap(v1)
3 33.9GB 240GB 206GB lvm

With "df -h" i can see what is inside the LVM mapper i guess which is:

Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_splat-lv_current 32G 12G 21G 36% /
/dev/sda1 291M 102M 174M 37% /boot
tmpfs 7.7G 6.7M 7.7G 1% /dev/shm
/dev/mapper/vg_splat-lv_log 72G 18G 55G 25% /var/log

Why the LVM mapper differs when i use parted and fdisk?

If the command "df -h" shows what is inside the LVM mapper why than the total space shown with "df -h" is 112G and with the other command 204G and 192G? Where the other 80G? Please help me understand this..

Also i would like to know what partition in the LVM mapper i have to increase in order to have enough space to make a snapshot? Is there any particular partition or just the free space in the LVM mapper?

Thank you very much

[G_W_Albrecht]

There is free space on HD kept for snapshots. LVM does not show partitions but logical volumes, see sk95566: Managing partition sizes via LVM manager on Gaia OS

[king_slavcho]

So according to this in order to make snapshot i have to make more free space on the HDD?