begin  quoting DJA as of Mon, Dec 10, 2007 at 11:20:16PM -0800:
> Carl Lowenstein wrote:
> >On Dec 10, 2007 5:14 PM, SJS <[EMAIL PROTECTED]> wrote:
[snip]
> >>>>So... without LVM, it's simple. I pull the CDROM, drop in the disk,
> >>>>partition, format, mount, and play with tar or rsync, modify fstab,
> >>>>pull the old disk, move the new disk, reconnect the CDROM, and bob's
> >>>>your uncle.
> 
> Yep, that's the way I commonly do it if I want to replace an existing 
> physical drive with another (presumably larger) one.

It's the baseline approach. One would hope that with LVM, it would be
easier.

> >>>>With LVM, is it even simpler?
> 
> Well, for me in these types of upgrades, fiddling with the hardware 
> rather than learning esoteric software has always been the more 
> expedient path.

One would think, well, hope, that the software would make the task
easier.  The pvmove command does seem to help a lot -- and if you had
hot-swappable devices (fireware, fiber-channel, etc.) then you could
upgrade a disk and never touch your uptime.

> >>>Yes. But you have to have empty space beforehand to allocate. Or you
> >>>have to do some gyrations to shrink a filesystem that has excess space
> >>>in order to reallocate it to the filesystem that needs it. Answers at
> >>><http://www.tldp.org/HOWTO/LVM-HOWTO/index.html>
> >>Specifically,
> 
> New hard drives are so cheap (and older spare ones usually abundant, if 
> needed) that I figure "Why bother with those kind of gymnastics?". I 
> just move the physical drive's contents to another of the needed size 
> and be done with it. It's not like I won't be able to use that old drive 
> (someone always needs more room in their hand-me-down system).

You're a CB's friend.

> >>...although it seems to require my changing where the CD-ROM drive
> >>connects into the IDE chain(s).  I would not consider this a _good_
> >>solution to the single most common disk-space problem I've ever had.
> 
> I guess I don't follow - you need the CD-ROM to run a Live-CD? If I am 
> moving data to another physical drive, the CD-ROM drive temporarily 
> gives up a needed connector on the data cable, to which it is returned 
> after the copy-swap process. I don't remember having problems just 
> copying data to another drive from a running system. If necessary, I'll 
> back it up to my file server as the intermediate medium.

All of the LVM examples I looked at mounted disks by location. e.g.,
"/dev/hda1".  Swapping disks around would interfere with that.

Presumably, disk labels could help here, but none of the examples I
looked at did it that way, nor did I see that question in the FAQ.
Maybe I just missed it.

If you're not using LVM, there's no problem at all. The new drive can
just drop in and replace the old drive.

[snip]
> That's THREE disks, right (Spare #1, Spare #2, and Disk-to-be-replaced)?

Indeed.

> Why bother with Spare #2? Just copy the data to Spare #1 (really a 
> replacement disk), swap disks, and  be done with it?

Can you tell LVM that /dev/hdb1 is now /dev/hda1 without losing
information?

[snip]
> As I usually do, if needed. If the computer can handle the new drive 
> being physically connected (i.e. has spare data and power connectors) 

Power is simple -- get a splitter, or use the CDROM's power. So long as
the power supply can handle the additional load, that is.

> then I don't need an intermediate medium. The new drive does not really 
> have to be bolted in - I just use an old anti-static shipping envelope 
> to insulate the drive while it's temporarily connected and lying 
> somewhere inside or outside the box.

I put the screws in the bottom, which gives the drive little feet that
keep the circuit board from touching anything.

>                                      Of course, with a laptop, it's 
> obviously a bit trickier.

Always.  But do laptops really last long enough to make it worthwhile
to replace the drive?

> Usually the intermediate medium is my fileserver. Not fast, but now that 
> my LAN is all Gigabit, fast enough for a home system. If needed, I just 
> run it overnight, and log the copy or rsync output to a file somewhere 
> so I can check to see if everything copied okay.

Heh. There ya go.

-- 
Waiting for the introduction of AoE to the topic.
Stewart Stremler


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