Lab
A Cloud Guru

Troubleshooting File System Issues

**Warning**: This lab represents a significantly broken environment and goes well beyond simple troubleshooting. In this lab, you must resolve any issues preventing the content mounted at `/storage` from being accessed. *This course is not approved or sponsored by Red Hat.*

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Path Info

Level

Advanced

Duration

4h 0m

Published

Apr 04, 2019

Challenge

Verify the iSCSI target configuration and status.
On Server1 (10.0.1.10)

Verify the target service is running:
```
systemctl status target
```
Start and enable the target service:
```
systemctl start target && systemctl enable target
```
Verify the process is listening on port 3260:
```
ss -ltnp | grep 3260
```
Check if the firewall is permitting traffic over 3260/tcp:
```
firewall-cmd --list-all
```
Permit incoming traffic over port 3260/tcp:
```
firewall-cmd --permanent --add-port=3260/tcp
```
Reload the firewall:
```
firewall-cmd --reload
```
View the iSCSI target configuration:
```
targetcli
```
```
/> ls
```

Challenge

Verify the iSCSI initiator configuration and status.

On Server2 (10.0.1.11)

View any existing node entires:

iscsiadm -m node

Verify the initiator name matches the ACL from the target:

cat /etc/iscsi/initiatorname.iscsi

Change the name to match the target:

InitiatorName=iqn.1994-05.com.redhat:c1cd6e78d22

Verify security settings match those of target:

less /etc/iscsi/iscsid.conf

#node.session.auth.authmethod = CHAP
...
#node.session.auth.username = username
#node.session.auth.password = password

Restart the iscsid service to pick up the change:

systemctl restart iscsid

Discover iSCSI targets from 10.0.1.10:

iscsiadm -m discovery -t sendtargets -p 10.0.1.10

iscsiadm -m node -T iqn.2003-01.org.linux-iscsi.ip-10-0-1-10.x8664:sn.a3776832068c -l

Enable the iscsid service to permit connection upon reboot:

systemctl enable iscsid

Challenge

Resolve disk encryption.
Review the contents of /etc/crypttab and /etc/fstab:
```
cat /etc/crypttab
```
```
cat /etc/fstab
```
Attempt to manually open the volume using the key referenced in /etc/crypttab:
```
cryptsetup luksOpen /dev/mapper/vg_1-lv_1 luks-vg_1-lv_1 --key-file /root/passphrase.key
```
View the volume key slots:
```
cryptsetup luksDump /dev/mapper/vg_1-lv_1
```
Restore the LUKS header:
```
cryptsetup luksHeaderRestore /dev/mapper/vg_1-lv_1 --header-backup-file /root/vg_1-lv_1.header
```
Open the volume manually:
```
cryptsetup luksOpen /dev/mapper/vg_1-lv_1 luks-vg_1-lv_1 --key-file /root/passphrase.key
```
View the entries in /dev/mapper:
```
ll /dev/mapper
```
Attempt to mount /storage:
```
mount /storage
```
View the file system label:
```
blkid
```
The volume appears to be a swap format, however the entry in /etc/fstab suggests it's an XFS file system. Repair the file system:
```
xfs_repair /dev/mapper/luks-vg_1-lv_1
```
Mount /storage:
```
mount /storage
```
View the contents of /storage:
```
ll /storage
```

Author

A Cloud Guru

The Cloud Content team comprises subject matter experts hyper focused on services offered by the leading cloud vendors (AWS, GCP, and Azure), as well as cloud-related technologies such as Linux and DevOps. The team is thrilled to share their knowledge to help you build modern tech solutions from the ground up, secure and optimize your environments, and so much more!

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