[wplug] Install Resolution

[Bryan J. Smith]

On Thu, 2007-07-26 at 13:34 -0700, n schembr wrote:
> I would  use  separate  drive for the root file system.  I've  never
> liked  having  boot disk with a striped down environment.
> I like having a spare disk that I can swap in place of a failed root.

On Thu, 2007-07-26 at 16:37 -0400, Michael H. Semcheski wrote:
> This is a 1u server, with space for exactly 4 drives, and we need all
> 4 drives.  If I was going to have a seperate boot drive, it would need
> either 3 drives, or larger drives, or less space in the array.

Just FYI ... you _could_ ...
1)  Remove 1 disk from the RAID-5 array
2)  Either add 1 disk as a JBOD, or connect the SATA to mainboard
3)  Mount the [degraded] RAID-5 array read-only
4)  Copy over the core "system" filesystems (/, /tmp, /var, etc...)

I don't know if #2 will work as JBOD, the 3Ware intelligence won't like
you taking it out of the array.  So it's best to just use a standalone
disk connected to the mainboard array as your "backup" that you can
throw in (along with switching the cable).

[ SIDE NOTE:  In a 3U chassis, I throw in a 5x1" SATA chassis, so I can
have a "spare" drive for connecting to the mainboard SATA and exactly
that "recovery" option. ]

On Thu, 2007-07-26 at 13:34 -0700, n schembr wrote:
> I have used rsync to copy from sda1 to sdb1.   Since all active /
> open file  will be on the array, it is a very fast and clean sync.

That and a quick sed on the /boot/grub.conf to install a MBR to the
spare drive so it's ready-to-boot.

On Thu, 2007-07-26 at 16:37 -0400, Michael H. Semcheski wrote:
> Perhaps down the road, all the boot drives will be flash based.
> Should be quicker, less likely to fail, and not likely to hit the 2TB
> limit soon!

CompactFlash and USB uses ATA emulation so they have bigger issues at
128GiB (137GB) for LBA 28-bit.

On Thu, 2007-07-26 at 14:04 -0700, n schembr wrote:
> You could use a usb device as a backup root file system if the RAID
> fails.  Have  usb-drive set as the second boot device.

It's always very nice to have this!  In general, you want to be able to
_boot_ into a "recovery" mode _ASAP_.  I consider that a "common sense"
disaster recovery fundamental (aimed at those who don't want to spend
much):  
http://thebs413.blogspot.com/2007/03/common-sense-disaster-recovery.html  

Mindi Boot (from Mondo Rescue) is a also good boot disk creator.

On Thu, 2007-07-26 at 14:04 -0700, n schembr wrote:
> Using the concepts from Voyage Linux,http://linux.voyage.hk/, a USB
> Drive might make a good root..  This will not have the raid support
> you need out of the box but...

That's what Mindi Boot is designed for ensuring.  ;)


-- 
Bryan J. Smith         Professional, Technical Annoyance
mailto:b.j.smith at ieee.org   http://thebs413.blogspot.com
--------------------------------------------------------
        Fission Power:  An Inconvenient Solution