[CentOS] Rescan harddisk size without rebooting

Bryan J. Smith thebs413 at earthlink.net
Sun Nov 13 15:07:06 UTC 2005

On Sat, 2005-11-12 at 22:28 -0600, Aleksandar Milivojevic wrote:
> If you do "fdisk /dev/sdb", does it show you correct (new) size?  Fdisk 
> should query device directly (and not relay on cached copy of partition 
> table in kernel).

On Sun, 2005-11-13 at 07:58 -0500, William L. Maltby wrote:
> A faster method is
>     sfdisk -l [/dev/xxxx]   # If no device specification, lists all
> and then
>     sfdisk -R /dev/xxx
> will load the disk parameters to the OS without reboot.

In both cases, assuming nothing on the disk is in use.  That's the
problem, you typically have to take down their PVs for LVM first.

> However, not being familiar with LVM, I don't know if this causes a
> problem or if you just then follow the other directions given by
> Aleksander.

LVM can rescan partitions.  The big problem here isn't LVM, it's the
fact that the kernel doesn't like to load low-level disk changes.

> I have also used this for automated configuration. But that was without
> LVM being involved.
Bryan J. Smith     b.j.smith at ieee.org     http://thebs413.blogspot.com
The best things in life are NOT free - which is why life is easiest if
you save all the bills until you can share them with the perfect woman

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