====== Nach Festplatten scannen ======

> In Linux, it’s a bit tricky since there is no direct ioscan available. First, you need to get currently available disk details using fdisk command as below :

<code bash>
# fdisk -l |egrep '^Disk' |egrep -v 'dm-'|grep -v identifier
Disk /dev/sda: 74.1 GB, 74088185856 bytes
Disk /dev/sdb: 107.4 GB, 107374182400 bytes
Disk /dev/sdd: 2147 MB, 2147483648 bytes
Disk /dev/sde: 2147 MB, 2147483648 bytes
Disk /dev/sdc: 2147 MB, 2147483648 bytes
</code>

> Keep this list handy to compare with the list after scan.

> **Scan SCSI disks**

> Now, if you have connected disks via SCSI then you need to scan SCSI hosts on the server. Check the current list of hosts on the server as below :

<code bash>
# ls /sys/class/scsi_host/
host0  host1  host2  host3
</code>

> Now, you have 4 hosts on this server (in the example above). You need to scan all these 4 hosts in order to scan new disks attached to them. This can be done by writing - - - in their respective scan files. See below commands:

<code bash>
echo "- - -" > /sys/class/scsi_host/host0/scan
echo "- - -" > /sys/class/scsi_host/host1/scan
echo "- - -" > /sys/class/scsi_host/host2/scan
echo "- - -" > /sys/class/scsi_host/host3/scan
</code>

> This completes your scan on SCSI hosts on the server. Now you can again run fdisk command we saw previously and compare the new output with the old one. You will see a new disk being added to the system and its respective device name too.

> **Scan FC LUNs:**

> If you have connected disks via FC then you need to scan FC hosts on the server. Check the current list of hosts on the server as below :

<code bash>
# ls /sys/class/fc_host
host0  host1
</code>

> Now there are 2 FC hosts on the server. Again we need to scan them by writing 1 to their respective issue_lip file along with scan steps from above.

<code bash>
# echo "1" > /sys/class/fc_host/host0/issue_lip
# echo "- - -" > /sys/class/scsi_host/host0/scan
# echo "1" > /sys/class/fc_host/host1/issue_lip
# echo "- - -" > /sys/class/scsi_host/host1/scan
</code>

> This will scan your FC HBA for new visible disks. Once the command completes (check syslog for completion event), you can use fdisk command to list disks. Compare the output with ‘before scan’ output and get new disk names!

[[https://kerneltalks.com/disk-management/howto-scan-new-lun-disk-linux-hpux/|Quelle]]

{{tag>[Linux Festplatte HDD Scan]}}