LinuxQuestions.org
Welcome to the most active Linux Forum on the web.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Server
User Name
Password
Linux - Server This forum is for the discussion of Linux Software used in a server related context.

Notices

Reply
 
Search this Thread
Old 06-29-2008, 08:14 AM   #1
=dn
LQ Newbie
 
Registered: Dec 2005
Location: LON
Distribution: SuSE 10.0
Posts: 12

Rep: Reputation: 0
Virtual disk allocation advice requested


I'm sick at home and in consolation am building myself a Xen VM test-bed
server - but have not used Xen before, nor LVM. I'll appreciate competent
advice about organising and allocating disk space, please.

Using a single large HDD initially, I thought:
a) primary partition, <1GB, ext3, /boot
b) LVM logical volume(s) for Xen's Dom0
c) multiple logical volumes, one for each Xen DomU
d) NFS shared space (both for network and between DomUs)
e) Samba shared space (somewhat optional because have other such spaces)
- that latter revealing that I have an heterogeneous network

Queries:
1 would it make better sense to put all of the Dom0 onto the primary
partition or even a separate extended partition?

2 for Dom0 I thought something like:
2GB, swap, /swap
5GB, reiser, /var
2GB, reiser, /root (rootuser)
10GB, ext3, /
but is it as necessary to break things out in a Dom0 situation?

3 I thought to use LVM logical volumes for the DomUs for the inherent
extensibility, eg one domain will be used to build an email server, and
if the project is successful I would add another HDD; but would it be
somehow better to use extended partitions?

4 I haven't figured out where/when/how one allocates space within a
DomU. Does/should one separate out space allocated to logs, the root
user, etc, as we were advised in 'the good old days' or has such gone by
the board/become irrelevant in the brave new virtual world?

5 will NFS 'play nicely' in an LVM logical volume or should it be an
extended partition?

6 similarly will Samba go into an LVM logical volume or should it be an
extended partition?

7 if I set up a DomU temporarily, eg to test some software/project, and
subsequently discontinue it, should I also remove the partition/virtual
disk allocated within LVM and then build space anew before creating some
future DomU, or can/should one simply recycle the nominated logical volume?

Any and all advice (or reference to reading materials) will be much
appreciated!
Regards,
=dn
 
Old 06-30-2008, 12:32 AM   #2
format C:
Member
 
Registered: Aug 2006
Location: IOWA
Distribution: Source Mage and Debian
Posts: 34

Rep: Reputation: 15
Don't know much about Xen, but I can help with some of the issues.
1: No clue, but I avoid LVM, as it messes up fs journaling, which can lead to all sorts of fun issues such as data corruption and file loss. Here is some info on it. Plus LVM has a performance hit, I've not benchmarked it, but you can "feel" it during disk intensive operations.
2: Don't know, how you partition your fs all depends on your usage. I usually do a 100MB /boot, 2x the RAM for swap, 10GB-25GB for / and the rest for /home.
3: See #1
5/6: These are network protocols are are file system agnostic. They don't care how your disk is partitioned as long as the files are accessible. You could do an NFS share of a SMB share from a Windows machine mounted on your system.

Hope that helps a bit
 
Old 06-30-2008, 05:28 AM   #3
=dn
LQ Newbie
 
Registered: Dec 2005
Location: LON
Distribution: SuSE 10.0
Posts: 12

Original Poster
Rep: Reputation: 0
Sadly not much help: Xen's disk virtualisation involves something of a performance hit, and sparse files are NOT the answer. However I'll be watching the performance issues for the same reasons as stated!

Having so many partitions, as advised, multipled across so many VMs, seems to me that we run out of partitions before too long, hence the thoughts about LVM...

I have since noted that paravirtualisation (which I didn't include earlier) apparently contra-indicates the use of journalled file systems in certain situations (SuSE documentation).

Regards,
=dn
 
Old 06-30-2008, 09:54 AM   #4
format C:
Member
 
Registered: Aug 2006
Location: IOWA
Distribution: Source Mage and Debian
Posts: 34

Rep: Reputation: 15
An extended partition allows for either 127 or 255 logical disks inside it, can't remember the exact number, so you should be okay with that.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
C advice requested freeindy Programming 4 07-19-2007 05:19 AM
Advice requested for Linux installation (more interesting than it sounds!) Napalm Llama Linux - General 20 06-29-2006 06:49 PM
Presentation on Linux - advice requested pattyz Linux - General 2 03-16-2006 08:38 AM
Partition advice requested bamatmac Linux - Newbie 1 12-30-2005 01:28 PM
LAMP advice requested thorn168 *BSD 2 04-19-2005 12:04 AM


All times are GMT -5. The time now is 01:39 AM.

Main Menu
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration