Re: [PLUG] Your recommendations

[Matthew Rosewarne <mrosewarne@inoutbox.com>]

On Saturday 15 November 2008, Ugarit Ebla wrote:
> Do I first make each partition a RAID then LVM or the other way around?

GRUB 2 method:
Make one partition on each drive in the array that spans the entire drive:
	/dev/hd[abcd]1:	750GB (whole drive)

Add those partitions to your RAID array:
	/dev/hda1 --\
	/dev/hdb1 -\ \
               -----> /dev/md0
	/dev/hdc1 -/ /
	/dev/hdd1 --/

Format /dev/md0 as a physical volume, then create a volume group and add 
/dev/md0 to it.
	/dev/md0 --> /dev/vg_foo (no need to name it vg*, but it's a good habit)

Carve your volume group into logical volumes as you please.



GRUB "Legacy" method:
Make a small (maybe ~100M) /boot partition on each drive, then a second 
partition that takes up the rest of the space.
	/dev/hd[abcd]1: 100ish MB
	/dev/hd[abcd]2: 750ish GB (whole drive - 100ish MB)

Make the small partitions to a RAID 1 array:
	/dev/hda1 --\
	/dev/hdb1 -\ \
               -----> /dev/md0
	/dev/hdc1 -/ /
	/dev/hdd1 --/

Format /dev/md0 as ext3 and set its mount point as /boot.  I'd also recommend 
labelling it "boot".

Make your main RAID array out of the large partitions:
	/dev/hda2 --\
	/dev/hdb2 -\ \
               -----> /dev/md1
	/dev/hdc2 -/ /
	/dev/hdd2 --/

Format /dev/md1 as a physical volume, then create a volume group and add 
/dev/md1 to it.
	/dev/md1 --> /dev/vg_foo (no need to name it vg*, but it's a good habit)

Carve your volume group into logical volumes as you please.

At the bootloader stage, I believe the installer is smart enough to know what 
to do when asked to install GRUB to a RAID-1 device.  If instead I just made 
that up, you'll need to install manually as described here: 
http://grub.enbug.org/MirroringRAID

> I was thinking of this partition table:
>
>
> /       30 GB
/ need only be about 10G for now.  Add more later if you require.

> /boot    1 GB
/boot is unnecessary with GRUB 2, and on a separate partition with GRUB 
Legacy.  Even then, 100MB should be more than enough.

> /var   100 GB
> /home  100 GB
That's mighty big.  Just give it the minimum it needs, add a few GB for elbow 
room, then grow it later if you need more space.

> /tmp     5 GB
You might want to consider mounting /tmp as a tmpfs, which resides in RAM (or 
more probably in swap).  That means it'll be fast when programs throw numerous 
temporary files around, and also be cleared on reboot automatically.  Make 
sure to add whatever space you would be using for /tmp to swap.  5GB seems a 
bit high, but I don't know what your programs tend to put in there.

> swap    10 GB
If you find your machine using more than a gig or two of swap at absoleute 
peak load, you need more RAM.  If you find your machine resorting to swap 
under normal circumstances, you need more RAM.  Also, if your bicycle has a 
gun rack, you may be a redneck.

Attachment: signature.asc
Description: This is a digitally signed message part.

___________________________________________________________________________
Philadelphia Linux Users Group         --        http://www.phillylinux.org
Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce
General Discussion  --   http://lists.phillylinux.org/mailman/listinfo/plug