Hello,
>I agree with Simon.
>
>When you are talking about a couple of Terabytes, most Raid Arrays
effectively
>have their own LVM built in.
First of all, thanks to all for your responses.
Now, the storage solution I am talking about (unfortunately I'm not allowed
to be specific here, for the moment) is, what you called a high-end one,
and has some kind of LVM of it's own but from what I understood, it cannot
simply grow an existing logical volume. It has an internal RAID 5 and I've
been told that "it could have been done but it's not for the reason of
security". I can see some point in this, they want to maintain data
integrity (the way the device works internally is quite complex). So, what
happens is that when I want to "enlarge" the volume, I get (physically, in
the OS) a new device, like /dev/sdc. And now I'm on my own to grow a
filesystem, so I need to use software LVM..
>Generally, software LVM is just needed for 2 features:
>
>Snapshots: This is available in many Raid systems, but it can be a fairly
>expensive option, so many people prefer software snapshots. Since XFS
does not
>to my knowledge directly support snapshots, one is left to consider a
software
>LVM vs. paying for the hardware option.
As you say, this is a fairly expensive option :) But unfortunately, LVM1 is
deadlocking with xfs_freeze - anyone has any EVMS experience?
>Mirroring between Raid Arrays: Some truly paranoid people use LVM to
mirror 2
>standalone Raid Arrays to together. This is pretty rare because it is
very
>expensive to do. I doubt you are planning on doing this.
Yes, I won't do that.
Marek Les
Seznam.cz
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