Category: SCSI Stuff

admin | July 1, 2020

How to add a new SCSI LUN while server is Live

REDHAT/CENTOS:

In order to get wwn ids from a server:

• cat /sys/class/scsi_host/host0/device/fc_host\:host0/port_name

• cat /sys/class/scsi_host/host1/device/fc_host\:host1/port_name

Or:

• systool -av -cfc_host | grep port_name | awk ‘{ print $3 }’ | cut -d\” -f 2 | cut -dx -f 2

1.To add a new SAN LUN while live:

Run this to find the new disks after you have added them to your VM

• rescan-scsi-bus.sh

Note: rescan-scsi-bus.sh is part of the sg3-utils package

2.Check that it has been found, will be mpath(something)

• multipath –l

# That’s it, unless you want to fix the name from mpath(something) to something else

1.Change the shortcut name

• vi /etc/multipath_bindings

2.Remove the default mpath device autogenerated

• multipath –f mpath(something)

# Go into the multipath consolde and re add the multipath device with your new shortcut name (nickdsk2 in this case)

• multipathd –k

• add map nickdsk2

Note: Not going to lie, sometimes you could do all this and still need a reboot, majority of the time this should work. But what do i know…haha

admin July 1, 2020 Centos, Diskstuff, Linux, SCSI StuffNo Comments »

admin | June 17, 2020

How to increase disk size on virtual scsi drive using gpart

1.Login to VMware vSphere Client and shutdown server VM guest.

2.Select VM Guest server and click “Edit virtual machine settings”. Virtual Machine Properties window will appear. Under “Hardware”, click Hard Disk 2 (which is /data partition) and edit provision size to 200 GB as shown in below screenshot.
Power ON VM guest after editing disk size.

vsphere

3.Take VM snapshot of VM guest.

4.Log on to VM Guest using SSH client, like PuTTy, with “root” user.

5.List the SCSI devices using command – cat /proc/scsi/scsi

6.Run following command to see the name of the partition
ls -d /sys/block/sd*/device/scsi_device/* |awk -F ‘[/]’ ‘{print $4,”- SCSI”,$7}’

7.Run following commands to confirm the size of the SCSI disk for which you have increased size in step 4 has been updated by the following steps

1.echo 1 > /sys/class/scsi_device/2\:0\:1\:0/device/rescan

2.fdisk -l | grep Disk

3.df -h

8.Stop cron and services using commands
service crond stop

9.Unmount “/data” partition using command — umount /data
Note: If you observe “Device is busy” error then make sure that your current session is not in /data partition.

10.Perform following steps to grow added disk space of /data partition based on partition type

For GPT partition type

In this case parted -l command will give below for “sdb” disk partition
*****************************************************
Model: VMware Virtual disk (scsi)
Disk /dev/sdb: 215GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Number Start End Size File system Name Flags
1 1049kB 215GB 215GB ext4 Linux LVM lvm
*****************************************************