Re: [PLUG] CentOS 5 on >2TB disks

[Gordon Dexter <gordon@texasdex.com>]

Have you considered making a hybrid MBR?  This means you have both a GPT and an MBR partition table.  The GPT is in a different location so tools designed for MBR don't interfere with it.  Normally when you have a GPT the MBR is initialized to contain one partition, spanning the entire disk, of type 0xEE (GPT).  But there are tools designed to copy the layouts of the first four partitions from the GPT to the MBR so that older tools can still work.  I'm not sure what effect this has on how the kernel reads the partition table on >2TB disks, but it's worth looking into.

--Gordon

On Fri, Oct 8, 2010 at 7:13 AM, Doug Stewart <zamoose@gmail.com> wrote:

Why not map an LVM on top for everything with a single non-LVM partition cut for /boot at ~100MB?

--
Doug Stewart

On Oct 8, 2010, at 1:23 AM, JP Vossen <jp@jpsdomain.org> wrote:

> I have a case where I need to have LOTS of space in some servers.  Right now we're using Dell PE R710's with 6x 1TB drives like:
>    1+1 RAID1 mirror = ~1TB
>    4x  RAID5 = ~3TB
>
> The 1+1 mirror is a total waste, since all it has is the OS and some apps.  I'd much rather use all 6 drives in RAID5 for ~5TB.
>
> But if I do that, the boot device is >2TB and so the stock grub1 will barf.  And grub2 doesn't seem to be in the repos, and it's still a bit unclear to me if it can boot >2TB.  (I *think* it can, but...)  I'm not sure I really think grub2 is mature enough for critical production, but it it's the only game in town...
>
> I'm also not sure if there are any kernel issues with this.  Right now I'm using the stock CentOS kernel, but at some point I want to move to a custom, monolithic kernel.
>
> Throwing different hardware at the problem is a possibility.  The R710's are maxed out for drives, and I'm don't think there's a CF-Card or other option to stick the OS on so it's less than 2TB.  We're looking into R510's or something that can have more drives, so we might get smaller OS drives internally and leave the externally accessible ones for a big RAID.  But sooner or later I'm gonna need to deal with this on the R710s too.
>
> Is anyone booting Linux (esp. CentOS) on a boot device larger than 2TB?  Grub2 for CentOS?  Clues?
>
> Thanks,
> JP
> ----------------------------|:::======|-------------------------------
> JP Vossen, CISSP            |:::======|      http://bashcookbook.com/
> My Account, My Opinions     |=========|      http://www.jpsdomain.org/
> ----------------------------|=========|-------------------------------
> "Microsoft Tax" = the additional hardware & yearly fees for the add-on
> software required to protect Windows from its own poorly designed and
> implemented self, while the overhead incidentally flattens Moore's Law.
> ___________________________________________________________________________
> 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
___________________________________________________________________________
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

___________________________________________________________________________
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