Building clusters with UmVirt Linux From Scratch

Configuring simultaneous ULFS RAW disk image PXE-booting

Prepearing second ULFS raw image

go to /sources/iscsi directory
just copy ulfs.img to ulfs2.img
using kpartx tool from multipath-utils package create mapper device for partitions in ulfs2.img
```
kpartx -av ulfs2.img
```
create temporary mount point
```
mkdir /mnt/tmp
```
mount first partition to temporary directory
```
mount /dev/mapper/loop0p1 /mnt/tmp
```

open /mnt/tmp/boot/grub/grub.cfg file and replace netroot=iscsi:192.168.180.254::::iqn.2025-08.com.umvirt.nas:ulfs to netroot=iscsi:192.168.180.254::::iqn.2025-08.com.umvirt.nas:ulfs2:

menuentry "Umvirt Linux From Scratch 0.2.3 iSCSI " {
        linux   /boot/vmlinuz root=/dev/sda1 netroot=iscsi:192.168.180.254::::iqn.2025-08.com.umvirt.nas:ulfs2  \
                ip=dhcp ro  console=ttyS0 console=tty0
        initrd /boot/initramfs-6.13.4.img
}

also it's good idea to edit host name in /mnt/tmp/etc/hostname file to "ulfs-pxeclient2:" for example.
unmount partition from temporary directory
```
umount /mnt/tmp
```
delete mapper device for ulfs2.img
```
kpartx -dv ulfs2.img
```

Configuring PXE server

iPXE

Create file ulfs2 in /srv/tftp folder

    #!ipxe
    set initiator-iqn iqn.2016-04.com.open-iscsi:67637ebdf4a9
    sanhook --drive 0x80  iscsi:192.168.180.254:6:3260:0:iqn.2025-08.com.umvirt.nas:ulfs2
    sanboot --drive 0x80

Kea

Open kea config file "kea-dhcp4.conf".

In subne4 edit object reservations

"reservations": [
        {
            "hostname": "pxeclient1",
            "hw-address": "52:54:00:f1:13:66",
            "ip-address": "192.168.180.21",
            "boot-file-name": "ulfs"
        },
        {
            "hostname": "pxeclient2",
            "hw-address": "52:54:00:6d:f4:48",
            "ip-address": "192.168.180.22",
            "boot-file-name": "ulfs2"
        }

check config with
```
kea-dhcp4 -t /etc/kea/kea-dhcp4.conf
```
restart service
```
systemctl restart kea-dhcp4-server
```

iSCSI target configuration

open targetcli.

create link to file

cd backstores/fileio
create ulfs2 /sources/iscsi/ulfs2.img

create portal

cd /iscsi
create iqn.2025-08.com.umvirt.nas:ulfs2

create LUN

cd /iscsi/iqn.2025-08.com.umvirt.nas:ulfs2/tpg1/luns
create /backstores/fileio/ulfs2

create acl

cd ../acls
create iqn.2016-04.com.open-iscsi:67637ebdf4a9

disable authentication

cd /iscsi/iqn.2025-08.com.umvirt.nas:ulfs2/tpg1/acls/iqn.2016-04.com.open-iscsi:67637ebdf4a9
set attribute authentication=0

save
```
cd /
saveconfig
```
exit
```
exit
```

Check PXE clients booting

Just launch clients. Boot images should be assigned according to MAC addresses correctly.