VMware: Cannot extend virtual hard drive in vSphere UI, greyed out size - how to solve it and increase physical volume in Linux VM

Written by - 0 comments

Published on - Listed in VMWare Virtualization Linux

On a VM, running on VMware vSphere 6.7 and ESXi 6.7, the possibility to extend the virtual hard disk was greyed out:

VMware vsphere UI extend virtual hard disk greyed out

I checked with a couple of other systems and it was possible on all of them. What would be the difference between this particular VM and the others?

The snapshot, of course!

After some minutes of trying to spot a configuration, which would prevent online resizing, the reason was finally found: There was an snapshot on this VM!

Mr. T is telling you: Its the snapshot you fool!

Unfortunately in the new web-based vSphere user interface, an active snapshot cannot be seen as fast as in the earlier vSphere days (VMware Infrastructure and vSphere GUI). To check if a virtual machine still holds a snapshot, the "Actions" drop down menu needs to be opened, followed by the "Snapshots" entry to then finally click on "Manage Snapshots".

Vsphere UI: How to find snapshots

And here, finally, the snapshot can be deleted:

Vsphere UI: Show active snapshots

Back to online resizing

Once the snapshot was deleted, the virtual hard disks could be (online) resized again:

Online resizing in the VM (Linux)

Once the virtual hard disk was extended (not shrunk!), the virtual hard drive can be extended within the operating system (here CentOS Linux), without downtime, too! This was already explained in an older article (Dynamically increase physical volume (PV) in an LVM setup on a VM) but for the sake of completeness of this article, here's the info again.

First the correct drive needs to be identified:

[root@vm ~]# pvs
  PV         VG         Fmt  Attr PSize   PFree
  /dev/sda5  vgsystem   lvm2 a--    6.00g 4.00m
  /dev/sdb   vgdb       lvm2 a--  <60.00g    0
  /dev/sdc   vgtmp      lvm2 a--  <30.00g    0
  /dev/sdd   vgapp      lvm2 a--  <10.00g    0
  /dev/sde   vgdbbackup lvm2 a--  <50.00g    0 

In vSphere UI the 5th hard drive had an original size of 50GB and as there is only one physical volume with that size (SDE) the drive is identified!

Note: The order of hard drives in vSphere UI does not forcibly match the order in the OS, watch out!

We can now tell the Kernel to rescan this particular drive (sde). To do this, the exact scsi device path needs to be found first:

[root@vm ~]# ll /sys/block/sde/device
lrwxrwxrwx 1 root root 0 Dec 11 08:13 /sys/block/sde/device -> ../../../0:0:4:0

And then the Kernel is told to rescan this path:

[root@vm ~]# echo 1 > /sys/class/scsi_device/0\:0\:4\:0/device/rescan

With fdisk, the new size can already be seen:

[root@vm ~]# fdisk -l /dev/sde

Disk /dev/sde: 69.8 GB, 69793218560 bytes, 136314880 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Resize the PV:

[root@vm ~]# pvresize /dev/sde
  Physical volume "/dev/sde" changed
  1 physical volume(s) resized or updated / 0 physical volume(s) not resized

And voilĂ , the new space is available in the VG:

[root@vm ~]# vgs
  VG         #PV #LV #SN Attr   VSize   VFree
  vgapp        1   1   0 wz--n- <10.00g     0
  vgdb         1   1   0 wz--n- <60.00g     0
  vgdbbackup   1   1   0 wz--n- <65.00g 15.00g
  vgsystem     1   2   0 wz--n-   6.00g  4.00m
  vgtmp        1   1   0 wz--n- <30.00g     0 

Add a comment

Show form to leave a comment

Comments (newest first)

No comments yet.

RSS feed

Blog Tags:

  AWS   Android   Ansible   Apache   Apple   Atlassian   BSD   Backup   Bash   Bluecoat   CMS   Chef   Cloud   Coding   Consul   Containers   CouchDB   DB   DNS   Database   Databases   Docker   ELK   Elasticsearch   Filebeat   FreeBSD   Galera   Git   GlusterFS   Grafana   Graphics   HAProxy   HTML   Hacks   Hardware   Icinga   Influx   Internet   Java   KVM   Kibana   Kodi   Kubernetes   LVM   LXC   Linux   Logstash   Mac   Macintosh   Mail   MariaDB   Minio   MongoDB   Monitoring   Multimedia   MySQL   NFS   Nagios   Network   Nginx   OSSEC   OTRS   Office   PGSQL   PHP   Perl   Personal   PostgreSQL   Postgres   PowerDNS   Proxmox   Proxy   Python   Rancher   Rant   Redis   Roundcube   SSL   Samba   Seafile   Security   Shell   SmartOS   Solaris   Surveillance   Systemd   TLS   Tomcat   Ubuntu   Unix   VMWare   VMware   Varnish   Virtualization   Windows   Wireless   Wordpress   Wyse   ZFS   Zoneminder