GPT bootdisk on a non-EFI system

[Sheratan]

A server just came to my house. IBM x3250 M4. My friend ask me to install CentOS 6 64-bit. But after create the partition with CentOS default scheme:

/500 boot
/4000 swap
/ the rest of it

A warning appeared:

You are using a GPT bootdisk on a non-EFI system. This may not work, depending on you BIOS's support for booting from GPT disks

It's a 286102 MB (300GB roughly) Strange isn't?

Any help will be appreciated.

 

[TPerry]

Install Debian?

Make sure the server bios is updated to the latest version.

 

[Floren]

@Sheratan, don't use the default partitioning, is very bad. Instead, create 2 physical partitions, one for /boot and one for LV's. Example of proper partitioning:

# pvs
  PV         VG    Fmt  Attr PSize   PFree
  /dev/md1   vg_os lvm2 a--  930.88g 807.88g
# vgs
  VG    #PV #LV #SN Attr   VSize   VFree
  vg_os   1   6   0 wz--n- 930.88g 807.88g
# lvs
  LV      VG    Attr       LSize  Pool Origin Data%  Move Log Cpy%Sync Convert
  lv_home vg_os -wi-ao---- 10.00g
  lv_opt  vg_os -wi-ao---- 10.00g
  lv_root vg_os -wi-ao---- 10.00g
  lv_swap vg_os -wi-ao----  8.00g
  lv_tmp  vg_os -wi-ao----  5.00g
  lv_var  vg_os -wi-ao---- 80.00g
# df -ah
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/vg_os-lv_root
                      9.9G  1.6G  7.8G  18% /
proc                     0     0     0    - /proc
sysfs                    0     0     0    - /sys
devpts                   0     0     0    - /dev/pts
tmpfs                 3.8G     0  3.8G   0% /dev/shm
/dev/md0              496M  123M  348M  27% /boot
/dev/mapper/vg_os-lv_home
                      9.9G  200M  9.2G   3% /home
/dev/mapper/vg_os-lv_opt
                      9.9G  151M  9.2G   2% /opt
/dev/mapper/vg_os-lv_tmp
                      5.0G  139M  4.6G   3% /tmp
/dev/mapper/vg_os-lv_var
                       79G  2.0G   73G   3% /var

If you need more detailed help, feel free to ask your questions.

Install Debian?

Make sure the server bios is updated to the latest version.

Nothing to do with it. And a NO for Debian.

 

[Sheratan]

LVM Volume Groups
> VolGroup 285100
--- LogVol01 281100   /        ext4
--- LogVol00 4000              swap

Hard Drives
> sda
--- sda1     1000     /boot    ext4
--- sda2     285101   VolGroup physical volume (LVM)

This is good? Still show warning...

 

[TPerry]

@Sheratan, don't use the default partitioning, is very bad. Instead, create 2 physical partitions, one for /boot and one for LV's.

Nothing to do with it. And a NO for Debian.

Apparently it has been seen before and the suggestion was to update the bios.... and if it was "very bad" then I wouldn't think it would be the default for an install - or at least to a reasonable person it wouldn't be.
Having to set "custom partitions" up is a little ass-backwards for an easy installation experience. Granted, most people installing a server would be familiar with it, but not everyone is. I did notice on my last install of a test VPS that the graphical install (which BTW, required at least a 1.5GB memory footprint for the VPS) gave several options.

Choosing the first option should be enough for a user to utilize without having to customize their layout.

Did I happen to mention that the graphical install appears to be a memory hog... unlike Debian's.

 

[Floren]

@Tracy Perry, Create Custom Layout (last option on your screenshot) is the way to go, trust me I talk from over 15 years of dealing with it.
Let me give you the perfect example: Say you partitioned the swap to 8GB with your default configuration. What will you do if you need to add more RAM and double the swap size in 6 months? You are screwed. Yes you can tell me that you could add a swap file but this is an atrocious fix and has performance issues.

The proper way is to build your LV's and increase their size as you need it. Period.
My example is self explanatory, even if I have a 1TB vg_os volume group, I only use 80GB to /var. If I need to increase the LV size, it can be done on the fly with no down time. Increasing the swap partition is also a breeze, using the same technique. What better solution than this you need?

 

[TPerry]

@Tracy Perry, Create Custom Layout (last option on your screenshot) is the way to go, trust me I talk from over 15 years of dealing with it.
Let me give you the perfect example: Say you partitioned the swap to 8GB with your default configuration. What will you do if you need to add more RAM and double the swap size in 6 months? You are screwed. Yes you can tell me that you could add a swap file but this is an atrocious fix and has performance issues.

The proper way is to build your LV's and increase their size as you need it. Period.
My example is self explanatory, even if I have a 1TB vg_os volume group, I only use 80GB to /var. If I need to increase the LV size, it can be done on the fly with no down time. What better solution than this you need?

[root@testb home]# pvs
  PV         VG       Fmt  Attr PSize  PFree
  /dev/sda2  vg_testb lvm2 a--  79.51g    0

Filesystem                   1K-blocks   Used Available Use% Mounted on
/dev/mapper/vg_testb-lv_root  51606140 866400  48118300   2% /
tmpfs                           961188      0    961188   0% /dev/shm
/dev/sda1                       495844  32680    437564   7% /boot
/dev/mapper/vg_testb-lv_home  26391624 176096  24874908   1% /home

I assumed that the LV in lv_root referred to Logical Volume... as in LVM. Does it not?
BTW, this was just a down and dirty quick install to look at the options.

 

[Floren]

I assumed that the LV in lv_root referred to Logical Volume... as in LVM. Does it not?

Yes.

BTW, this was just a down and dirty quick install to look at the options.

Please make me a favor and get rid of that crazy partitioning you posted above. Have a good read on Red Hat documentation site to understand the importance of proper partitioning, you will see what I mean. I'm really surprised that you did not set your partitioning like in my previous example.

Edit: I mean your logic is good, you just have to do a deeper partitioning and preserve the free space.
Don't allocate the entire free space to /, is crazy.

 

[TPerry]

@Tracy Perry, please make me a favor and get rid of that crazy partitioning you posted above. Have a good read on Red Hat documentation site to understand the importance of proper partitioning, you will see what I mean. I'm really surprised that you did not set your partitioning like in my previous example.

Edit: I mean your logic is good, you just have to do a deeper partitioning.

Honestly.... since I have no real desire to delve into centOS to that depth since I never plan on using it.
And as I said, that is a down and dirty quick test install using the default centOS option (which you would expect to be more optimized if it's so bad).
And, I am going to be upfront and say that Debian isn't much better on their default either if you choose everything in the / partition. For the VPS's I set up I don't really worry that much about shoving everything into separate partions. It's a simple matter of allocating more space on the VM front end, quick boot to GParted and resize. LVM would probably be "simpler" but I've never had any problem with GParted other than the fact their is a few minutes of down time.

On a dedicated server LVM would be more important - but most of the VM interfaces for VPS's that I have experienced use GParted or something similar (if they don't already have it automated like DO).
I guess now I need to set up a VPS with Debian and LVM.

 

[Floren]

The partitioning logic I explained above is for any Linux OS, not just Red Hat. Is common practice to keep as much space as possible free and allocate it WHEN you need it, to the LV you need it.

 

[TPerry]

The partitioning logic I explained above is for any Linux OS, not just Red Hat. Is common practice to keep as much space as possible free and allocate it WHEN you need it, to the LV you need it.

But not everybody uses LVM.
and out of curiosity I did hit Redhat's site

9.15.5.1. x86, AMD64, and Intel 64 systems
We recommend that you create the following partitions for x86, AMD64, and Intel 64 systems:
A swap partition
A /boot partition
A / partition
A home partition

Further in it does go into more detail for special needs.
From reading it looks also like it's needed for the fact that you can't upgrade the distribution in place? I can see the need then for separate partitions since you wouldn't want to wipe certain areas on a distro upgrade (which I don't have to worry about as I can do a distro upgrade in place).

The only thing that isn't done in the default centOS install is the home partition - and for me I never keep anything in home that I need to share.

 

[TPerry]

Edit: I mean your logic is good, you just have to do a deeper partitioning and preserve the free space.
Don't allocate the entire free space to /, is crazy.

For my needs (configuring it as a VPS) it's not really. I'm not really sure (have to do some playing/research - same thing) using an LVM on the VPS and allocating more drive space and see how it works. Probably the same way, and if so I'll more than likely start using LVM instead of the old way of doing it. On the VPS's we aren't talking TBs of drive capacity but usually a few hundred GB at the most.

 

[Floren]

All VM's I create at work have a standard 60GB vistual disk. Yet, I partition them as I mentioned earlier, always. The Red Hat documentation is there just to give you VERY basic guidelines. I explained very clearly why you SHOULD partition properly your disks from the start, that is valid for ANY Linux OS. Google is your friend to delve deeper, or we can engage on a deeper talk on my forums.

 

[Sheratan]

So some guys said I need to put IBM Server Guide CD's first before installing any OS... and I don't have one.

But IBM provide the ISO in their website, so I'm downloading that right now. Let's see what can I do.

 

[WSWD]

Let me give you the perfect example: Say you partitioned the swap to 8GB with your default configuration. What will you do if you need to add more RAM and double the swap size in 6 months?

Absolutely nothing, because the swap:RAM ratio is a 100% a ridiculous myth, that fly-by-night "system admins" have been propagating for years. Absolutely no reason to raise the swap space simply because you add more RAM. The myth originated with Sun OS4, and is just that...a complete myth.

If you find that you're using tons of swap and need to expand the partition, just add more RAM. It's cheap enough...

 

[Floren]

@Sheratan, I never heard of that and I installed several times Red Hat on IBM machines. Where did you read this?
@WSWD, I always did that and kept the swap to 8GB... but isn't nice to be able to properly increase the swap size the easy way if you want to? You know exactly what I mean and I'm sure you agree 100% with the partitioning scheme logic I posted earlier.

 

[WSWD]

@WSWD, I always did that and kept the swap to 8GB... but isn't nice to be able to properly increase the swap size the easy way if you want to? You know exactly what I mean and I'm sure you agree 100% with the partitioning scheme logic I posted earlier.

For what reason? You shouldn't be using tons of swap in the first place. If you're using more than 8GB of swap, it's time to add more RAM.

 

[Floren]

@WSWD, I was talking about the overall partitioning scheme, we already closed the swap chapter when you posted your good argument.

 

[TPerry]

I think (for me now) GParted is quicker.

 

[Sheratan]

@Sheratan, I never heard of that and I installed several times Red Hat on IBM machines. Where did you read this?

It's for Windows only, something about RAID configuration and extra drivers.

I'm stuck. No where to go. After installing Centos with LVM, I see only "Boot Failed" after restart.

Going to bios and changing the disk into non-EPT, the GPT bootdisk error (as above) is gone but guess what I got:



What a nice little floppy!