CentOS - Feb 2011 - CentOS Digest, Vol 73, Issue 3

On 02/03/2011 09:00 AM, Lamar Owen wrote:
> ------------------------------
>
> On Wednesday, February 02, 2011 08:04:43 pm Les Mikesell wrote:
>> >  I think there are ways that drives can fail that would make them
not be detected
>> >  at all - and for an autodetected raid member in a system that has
been rebooted,
>> >  not leave much evidence of where it was when it worked.  If your
slots are all
>> >  full you may still be able to figure it out but it might be a
good idea to save
>> >  a copy of the listing when you know everything is working.
> I'll echo this advice.
>
> I guess I'm spoiled to my EMC arrays, which light a yellow LED on the
DAE and on the individual drive, as well as telling you which backend bus, which
enclosure, and which drive in that enclosure.  And the EMC-custom firmware is
paranoid about errors.
>
> But my personal box is a used SuperMicro dual Xeon I got at the depth of
the recession in December 2009, and paid a song and half a dance for it.  It had
the six bay hotswap SCSI, and I replaced it with the six bay hotswap SATA, put
in a used (and cheap) 3Ware 9500S controller, and have a RAID5 of four 250GB
drives for the boot and root volumes, and an MD RAID1 pair of 750GB drives for
/home.  The Supermicro motherboard didn't have SATA ports, but I got a
64-bit PCI-X dual internal SATA/dual eSATA low-profile board with the
low-profile bracket to fit the 2U case.  Total cost<$500.
>
Less than $500 for a Supermicro box?  Holy crap, Batman!

I'm using one of their motherboards (X8DAL-3) in a home-brew 
configuration, which has turned out to be somewhat less expensive than a 
factory-built Supermicro, but still not cheap.  I'll say one thing for 
them ... they do make really nice stuff, with little extras the 
commodity makers like Asus or Gigabit don't include.  Well worth the 
extra dollars.  This box just screams, so it should handle KVM very 
nicely if I organize the arrays properly ... anyone with RAID-60 advice 
please chime in.

I took Les' advice and built a connection map of the 15 drives.  The 
Disk Utility GUI turned out to be useful once I determined the SATA 
breakout cable order and labelled each with its PHY number.  Knowing 
that lets me use the GUI to clearly identify a failed drive, which shows 
up as a PHY#.  I'm normally a command-line kinda guy but this utility is 
something I really like on RHEL-6.  I hope it's the same on CentOS-6.

I'll organize the disk arrays with this trial version of RHEL, on the 
assumption that CentOS-6 simply picks them up as-built.

Chuck

On 2/3/2011 12:38 PM, Chuck Munro wrote:
>
> Less than $500 for a Supermicro box?  Holy crap, Batman!
>
> I'm using one of their motherboards (X8DAL-3) in a home-brew
> configuration, which has turned out to be somewhat less expensive than a
> factory-built Supermicro, but still not cheap.  I'll say one thing for
> them ... they do make really nice stuff, with little extras the
> commodity makers like Asus or Gigabit don't include.  Well worth the
> extra dollars.  This box just screams, so it should handle KVM very
> nicely if I organize the arrays properly ... anyone with RAID-60 advice
> please chime in.
>
> I took Les' advice and built a connection map of the 15 drives.  The
> Disk Utility GUI turned out to be useful once I determined the SATA
> breakout cable order and labelled each with its PHY number.  Knowing
> that lets me use the GUI to clearly identify a failed drive, which shows
> up as a PHY#.  I'm normally a command-line kinda guy but this utility
is
> something I really like on RHEL-6.  I hope it's the same on CentOS-6.
If you are building your own stuff, I kind of like trayless hot-swap 
sata bays.  And if you care more about size and power than speed and 
capacity, you can get them for laptop size drives too.

-- 
   Les Mikesell
    lesmikesell at gmail.com

On Thursday, February 03, 2011 01:38:35 pm Chuck Munro
wrote:
> On 02/03/2011 09:00 AM, Lamar Owen wrote:
> > But my personal box is a used SuperMicro dual Xeon I got at the depth
of the recession in December 2009
> Less than $500 for a Supermicro box?  Holy crap, Batman!
Hey, first let me thank you for trimming the rest of the digest out in your
reply; that's good stuff.

Next, this is an older Supermicro board, P4DP6, and older 32-bit-only
Xeon's, 2.8GHz.  But it has 4GB of ECC RAM, and the nice 2U Supermicro rack
chassis with the six bay trayless drive array.  And, again, the total package,
except for the drives, which I already had on hand, was less than $500, and that
included the 3ware controller and the SiI SATA-2 low profile 64-bit PCI-X board.
> I took Les' advice and built a connection map of the 15 drives.  The 
> Disk Utility GUI turned out to be useful once I determined the SATA 
> breakout cable order and labelled each with its PHY number.  Knowing 
> that lets me use the GUI to clearly identify a failed drive, which shows 
> up as a PHY#.  I'm normally a command-line kinda guy but this utility
is
> something I really like on RHEL-6.  I hope it's the same on CentOS-6.
Should be.  As far as I know this is the same palimpsest that's in Fedora;
not sure of which version is in EL6, though.  It does pretty good, even gives
you a benchmarking utility, partitioning, formatting, SMART utilities, etc, all
in one place.

It works reasonably well over an ssh X tunnel, too, and is one reason my
standard install now includes at least the X libraries, even on a server.  There
are other reasons to have a remote GUI on a server, even if you disable the
display/desktop manager and GUI login.  I use ssh tunneled konqueror a lot, for
instance.  When you need to do large batches, CLI works best, but for just
drilling down into filesystems I do like konqueror, from either KDE3 or KDE4,
doesn't really matter that much to me.  And it's reasonably fast even
over DSL.

And my main server management station runs ssh tunneled gkrellm instances from
critical servers; it's easy to tell at a glance if something has happened to
a server, and it makes for a pretty display in the datacenter during tours, too.