Rafik's questions

During the installation of my centos stream 8 OS I gave /var a size of 10GB thinking it would be more than enough, but after I started using docker I found of that it takes too much space on the /var partition as it is shown by the df command:

[root@compute-07 ~]# df -h
Filesystem           Size  Used Avail Use% Mounted on
devtmpfs              28G     0   28G   0% /dev
tmpfs                 28G     0   28G   0% /dev/shm
tmpfs                 28G  179M   28G   1% /run
tmpfs                 28G     0   28G   0% /sys/fs/cgroup
/dev/mapper/cs-root  371G  8.2G  363G   3% /
/dev/mapper/cs-home  100G  2.0G   98G   2% /home
/dev/mapper/cs-var    10G  9.0G  1.1G  90% /var
/dev/sda2            2.0G  412M  1.6G  21% /boot
/dev/sda1            2.0G  7.3M  2.0G   1% /boot/efi
/dev/mapper/cs-tmp    10G  105M  9.9G   2% /tmp
tmpfs                5.5G   16K  5.5G   1% /run/user/42
overlay               10G  9.0G  1.1G  90% 

/var/lib/docker/overlay2/77f74478297ca61595f0003d35c7323ec627adb44d94cef92c2b4a3c97319a66/merged
overlay               10G  9.0G  1.1G  90% /var/lib/docker/overlay2/5eeb399ce4a3c0d8065d63123985269a359fa66f4d20a8486326e466a48a0128/merged
overlay               10G  9.0G  1.1G  90% /var/lib/docker/overlay2/08d42ca66e3a5974bc305b502bca2aa4d22aa7ddcab6ea14c6af300b3abb3a70/merged
overlay               10G  9.0G  1.1G  90% /var/lib/docker/overlay2/1a45cb32b127fdf8f5c1483385139a865fdc69260ec20f3dcd4c56ad6890f909/merged
overlay               10G  9.0G  1.1G  90% /var/lib/docker/overlay2/ebb9af8edee824a4013dcd526e33e22272283bdee508fd43208fade557def728/merged
overlay               10G  9.0G  1.1G  90% /var/lib/docker/overlay2/41d55822108d04c85f348dc134fe6929b0e67f6b3bd7e0af147633bfd3a252c1/merged
overlay               10G  9.0G  1.1G  90% /var/lib/docker/overlay2/5cf3e8e06e9b4c2e6ed65164d91aed19f63d55e91524d6563e9f16b6709d29be/merged
overlay               10G  9.0G  1.1G  90% /var/lib/docker/overlay2/1d1eda94e68596b00d0cabcc75a7c91999a1c845ebd02c733bb9f00ac66a26f0/merged
overlay               10G  9.0G  1.1G  90% /var/lib/docker/overlay2/bc9e9a28c6761ad89a9457110642156ebd2b4d77de841f2a3ac9ffbaa90e4b63/merged

tmpfs                5.5G     0  5.5G   0% /run/user/0

This is the output of lsblk command, as /var is in a separate parition then / and /home I couldn't find a way to resize it or create another partition then link it to /var

[root@compute-07 ~]# lsblk
NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda           8:0    0 558.4G  0 disk 
├─sda1        8:1    0     2G  0 part /boot/efi
├─sda2        8:2    0     2G  0 part /boot
└─sda3        8:3    0 554.4G  0 part 
  ├─cs-root 253:0    0 370.4G  0 lvm  /
  ├─cs-swap 253:1    0    64G  0 lvm  [SWAP]
  ├─cs-tmp  253:2    0    10G  0 lvm  /tmp
  ├─cs-home 253:3    0   100G  0 lvm  /home
  └─cs-var  253:4    0    10G  0 lvm  /var
sr0          11:0    1  1024M  0 rom  

Is there any way I could resize this partition without having to lose any data.

I'm trying to use SR-IOV with openstack, and in order to check if the NIC available on my servers support this technolony I did the following:

(venv) [root@controller share]#  lshw -c network -businfo
Bus info          Device      Class          Description
========================================================
pci@0000:02:00.0  eno3        network        NetXtreme BCM5720 Gigabit Ethernet PCIe
pci@0000:02:00.1  eno4        network        NetXtreme BCM5720 Gigabit Ethernet PCIe
pci@0000:01:00.0  eno1        network        NetXtreme BCM5720 Gigabit Ethernet PCIe
pci@0000:01:00.1  eno2        network        NetXtreme BCM5720 Gigabit Ethernet PCIe
pci@0000:05:00.0              network        MT27500 Family [ConnectX-3]

and then :

(venv) [root@controller share]# lspci -vs 0000:02:00.0
02:00.0 Ethernet controller: Broadcom Inc. and subsidiaries NetXtreme BCM5720 Gigabit Ethernet PCIe
    DeviceName: NIC3
    Subsystem: Dell Device 1f5b
    Flags: bus master, fast devsel, latency 0, IRQ 51, NUMA node 0
    Memory at d58a0000 (64-bit, prefetchable) [size=64K]
    Memory at d58b0000 (64-bit, prefetchable) [size=64K]
    Memory at d58c0000 (64-bit, prefetchable) [size=64K]
    Expansion ROM at d8000000 [disabled] [size=256K]
    Capabilities: [48] Power Management version 3
    Capabilities: [50] Vital Product Data
    Capabilities: [58] MSI: Enable- Count=1/8 Maskable- 64bit+
    Capabilities: [a0] MSI-X: Enable+ Count=17 Masked-
    Capabilities: [ac] Express Endpoint, MSI 00
    Capabilities: [100] Advanced Error Reporting
    Capabilities: [13c] Device Serial Number 00-00-c8-1f-66-e0-30-22
    Capabilities: [150] Power Budgeting <?>
    Capabilities: [160] Virtual Channel
    Kernel driver in use: tg3
    Kernel modules: tg3

According to Redhat documentation sr-iov capable devices should have the following output with lspci -vs command :

    Capabilities: [160 v1] Single Root I/O Virtualization (SR-IOV)

But in my case I have :

    Capabilities: [160] Virtual Channel

and after searching about this result, I couldn't find any link between virtual channel and SR-IOV , does that mean the NIC on my servers do not support Single Root I/O Virtualization ?

In Openstack, is it possible to create compute nodes with no hard drives and use PXE in order to boot the host's system and therefore launch instances with no local drive which is needed to boot the VM's image.

If not what's the minimum storage needed to be given to hosts in order to get fully functional system.