linux-admin.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: urgrue <urgrue@bulbous.org>
To: kalinix <calin.kalinix.cosma@gmail.com>, linux-admin@vger.kernel.org
Subject: Re: Expand a raid volume
Date: Sat, 20 May 2006 23:02:07 +0300	[thread overview]
Message-ID: <446F75BF.3020904@bulbous.org> (raw)
In-Reply-To: <1148124928.18694.13.camel@mobilelinux>

 >> So from what I've read so far, there is no way to do an on-line
 >> expansion of the filesystem, I have to destroy the current
 >> filesystem, create it a new and restore the data. Not what I had
 >> hoped for when I bought a RAID card that does on-line expansion!

RAID creates a disk, on which you have partitions, on which you have 
filesystems. Until we get ZFS ported to linux (hopefully someday!), 
these are all different things entirely and have to be individually resized.
Download parted. It will resize your partitions and filesystems too. It 
has some limitations but it might be just what you need.

>> I was under the impression that LVM was a software RAID system and I 
>> wanted to use hardware RAID, did I get that wrong too?

LVM is not RAID. LVM has some RAIDish abilities (like mirroring) but 
LVM's main purpose is to allow flexible management of disks.
In other words, LVM allows you to make a "virtual" disk out of many 
physical disks.
Of course this sounds like RAID (adding disks to an array, etc) but 
essentially these are two different things designed for two different 
purposes, they just have some overlap. LVM shows up as a partition, 
which simplifies things. With RAID you will generally need to separately 
resize the array, the partition, and finally the filesystem.
Its generally a good idea to use LVM on servers, unless you know for 
sure your storage needs are going to remain quite static.

>> The plan is to slowly increase the available size on this server so I 
>> want to swap the 174GB SCSI disks for 300GB ones. 
>>
>> Should I recreate the whole system from scratch and use LVM?

Thats probably not necessary.
Your RAID card might allow you to replace the smaller disks and then 
expand them after the data has been rebuilt.
But overall switching to LVM is probably a good idea. I personally would 
  add the larger disks in a new array (you can do this one by one if you 
lack the space to add them all at once) and then create an LVM on top of 
that. Then you can migrate the data from the old array to the new one.



      reply	other threads:[~2006-05-20 20:02 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-05-16 17:43 Expand a raid volume Dermot Paikkos
     [not found] ` <1147803062.6153.7.camel@callahan_lt.tessco.com>
2006-05-16 18:24   ` Tom Callahan
2006-05-17 11:31     ` Dermot Paikkos
2006-05-20 11:35       ` kalinix
2006-05-20 20:02         ` urgrue [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=446F75BF.3020904@bulbous.org \
    --to=urgrue@bulbous.org \
    --cc=calin.kalinix.cosma@gmail.com \
    --cc=linux-admin@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).