[CentOS] safest way to grow a LV under VMware ESXi5.5

[m.roth at 5-cent.us]

Boris Epstein wrote:
> On Fri, Oct 30, 2015 at 12:57 PM, <m.roth at 5-cent.us> wrote:
>
>> Boris Epstein wrote:
> >
>> > In your view, what is the most reliable and safe way to increase an LV
>> > housing the root filesystem of a Centos 6 VM. I am thinking either
>> > growing the virtual HD virtual device, or creating a new device and
>> >  adding it as a PV to the VM, or perhaps migrating the whole FS
>> > to a new virtual disk.
>> >
>> > Any input on how best to proceed would be appreciated.
>> >
>> Dumb question: why do you need a larger root filesystem?
>>
>> First, how big is root? And if this is for stuff under, say, /var/www,
>> I'd make a separate logical drive/partition, and mount that, rsync
>> everything from /var/www to that, then shut down the web, and
>> remount the new filesystem on /var/www.
>>
>> Root, itself, doesn't need to be huge. We're using 500G, and seriously
>> considering making it 125G in the future, with data, or web stuff, is on
>> a separate partition, so when there's a sudden explosion of data, / is
>> safe.
>
> Well, we are talking much smaller scale here (only about 30 GB at
> present, planning to roughly double it).
<snip>
Ok, that *is* small. I'd worry about a logfile suddenly growing massively,
and freezing your system. (Yes, it has happened here, and then there was
the time a summer student ran something, wouldn't be back until Monday...
and got a 20G logfile, which blew out the NFS-mounted home directory fs,
on which a number of other people resided... including *me*, and his
manager, and our division head....)

       mark