Linux growing partitions on the fly with blockdev(1)
One thing I wished that Linux could do was to dynamically grow a partition online. This is something I was accustom to in HP-UX, AIX and even Solaris. It’s a pretty common operation to do in an enterprise environment with SAN LUNs. Lets say I have a web server running Apache on Linux. The htdocs dir sits on a dedicated SAN LUN and is slowly filling up. This server is a production box. Everything is using LVM. Before we can expand the FS, LV, or even the VG we need to grow the physical parition that the VG lives on. We expand the physical LUN size on the SAN, and fdisk the partition in Linux but linux still does not see the updated partition table size (without a reboot) – this is not good!
However, do not fear! I come across the very command to address this problem: blockdev –rereadpt /dev/sdX
Sigh… I wish I came across this command years ago!
