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Connecting a NAS to Linux via iSCSI

If your vCloud server and NAS storage are on separate machines, the most reliable way to connect them is iSCSI.

iSCSI allows the NAS to present a disk over the network, and Linux sees it as a local block device (like /dev/sdb). This is ideal for video storage because it usually performs better than SMB/NFS for large sequential writes.

Architecture

+-------------------+        iSCSI        +-------------------+
|   vCloud Server   | <-----------------> |        NAS        |
| Ubuntu Server     |                     | Synology/TrueNAS  |
| 192.168.1.10      |                     | 192.168.1.20      |
+-------------------+                     +-------------------+

Step 1 — Prepare the NAS

You need to configure the NAS and create an iSCSI LUN. To do this, refer to the user manual for your NAS server.

Step 2 — Install iSCSI Client on Ubuntu

On the vCloud server:

sudo apt update
sudo apt install open-iscsi -y

Enable the service:

sudo systemctl enable --now iscsid

Step 3 — Discover the NAS Target

Replace 192.168.1.20 with your NAS IP.

sudo iscsiadm -m discovery -t sendtargets -p 192.168.1.20

You should see something like:

192.168.1.20:3260,1 iqn.2026-07.local.synology:vcloud-storage

Step 4 — Configure Authentication (if CHAP is enabled)

Edit the node configuration:

sudo nano /etc/iscsi/iscsid.conf

Find and set:

node.session.auth.authmethod = CHAP
node.session.auth.username = vcloud
node.session.auth.password = StrongPassword123

Save the file.

Restart the service:

sudo systemctl restart iscsid

Step 5 — Log In to the iSCSI Target

sudo iscsiadm -m node --login

Expected output:

Login to [iface: default, target: iqn.2026-07.local.synology:vcloud-storage, portal: 192.168.1.20,3260] successful.

Step 6 — Verify the New Disk

List disks:

lsblk

Example:

sda    1.8T
├─sda1
└─sda2
sdb   10.0T

The iSCSI disk is usually sdb.

Step 7 — Create a Filesystem

⚠️ This will erase the iSCSI disk.

sudo mkfs.ext4 /dev/sdb

Step 8 — Create a Mount Point

sudo mkdir -p /mnt/vcloud-storage

Step 9 — Mount the Disk

sudo mount /dev/sdb /mnt/vcloud-storage

Check:

df -h

Example:

/dev/sdb        9.8T   24K  9.3T   1% /mnt/vcloud-storage

Step 10 — Make the Mount Persistent

Get the UUID:

sudo blkid /dev/sdb

Example:

/dev/sdb: UUID="a1b2c3d4-e5f6-7890-abcd-1234567890ef"

Edit /etc/fstab:

sudo nano /etc/fstab

Add:

UUID=a1b2c3d4-e5f6-7890-abcd-1234567890ef /mnt/vcloud-storage ext4 _netdev,nofail 0 2

Test:

sudo umount /mnt/vcloud-storage
sudo mount -a

If there are no errors, the configuration is correct.

Step 11 — Ensure iSCSI Reconnects After Reboot

Enable automatic login:

sudo iscsiadm -m node --op update -n node.startup -v automatic

Check:

sudo iscsiadm -m node

Useful Commands

Check iSCSI sessions

sudo iscsiadm -m session

Log out

sudo iscsiadm -m node --logout

Rediscover targets

sudo iscsiadm -m discovery -t sendtargets -p 192.168.1.20
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