LSI SAS2008 mps driver preferred firmware version

[Freddie Cash]

On Mon, Nov 16, 2015 at 12:57 PM, Slawa Olhovchenkov <slw at zxy.spb.ru> wrote:

> On Mon, Nov 16, 2015 at 11:40:12AM -0800, Freddie Cash wrote:
>
> > On Mon, Nov 16, 2015 at 11:36 AM, Kevin Oberman <rkoberman at gmail.com>
> wrote:
> > > As already mentioned, unless you are using zfs, use gpart to label you
> file
> > > systems/disks. Then use the /dev/gpt/LABEL as the mount device in
> fstab.
> > >
> >
> > ​Even if you are using ZFS, labelling the drives with the location of the
> > disk in the system (enclosure, column, row, whatever) makes things so
> much
> > easier to work with when there are disk-related issues.
> >
> > Just create a single partition that covers the whole disk, label it, and
> > use the label to create the vdevs in the pool.​
>
> Bad idea.
> Re-placed disk in different bay don't relabel automaticly.
>

​Did the original disk get labelled automatically?  No, you had to do that
when you first started using it.  So, why would you expect a replaced disk
to get labelled automatically?

Offline the dead/dying disk.
Physically remove the disk.
Insert the new disk.
Partition / label the new disk.
"zfs replace" using the new label to get it into the pool.​


> Other issuse where disk placed in bay some remotely hands in data
> center -- I am relay don't know how disk distributed by bays.
>

​You label the disks as they are added to the system the first time.  That
way, you always know where each disk is located, and you only deal with the
labels.

Then, when you need to replace a disk (or ask someone in a remote location
to replace it) it's a simple matter:  the label on the disk itself tells
you where the disk is physically located.  And it doesn't change if the
controller decides to change the direction it enumerates devices.

Which is easier to tell someone in a remote location:
  Replace disk enc0a6 (meaning enclosure 0, column A, row 6)?
or
  Replace the disk called da36?​
​or
  Find the disk with serial number XXXXXXXX?
or
  Replace the disk where the light is (hopefully) flashing (but I can't
tell you which enclosure, front or back, or anything else like that)?

The first one lets you know exactly where the disk is located physically.

The second one just tells you the name of the device as determined by the
OS, but doesn't tell you anything about where it is located.  And it can
change with a kernel update, driver update, or firmware update!

The third requires you to pull every disk in turn to read the serial number
off the drive itself.

In order for the second or third option to work, you'd have to write down
the device names and/or serial numbers and stick that onto the drive bay
itself.​


> Best way for identify disk -- uses enclouse services.
>

​Only if your enclosure services are actually working (or even enabled).
I've yet to work on a box where that actually works (we custom-build our
storage boxes using OTS hardware).

Best way, IMO, is to use the physical location of the device as the actual
device name itself.  That way, there's never any ambiguity at the physical
layer, the driver layer, the OS layer, or the ZFS pool layer.​


> I have many sites with ZFS on whole disk and some sites with ZFS on
> GPT partition. ZFS on GPT more heavy for administration.
>

​It's 1 extra step:  partition the drive, supplying the location of the
drive as the label for the partition.

Everything else works exactly the same.

I used to do everything with whole drives and no labels.  Did that for
about a month, until 2 separate drives on separate controllers died (in a
24-bay setup) and I couldn't figure out where they were located as a BIOS
upgrade changed which controller loaded first.  And then I had to work on a
server that someone else configured with direct-attach bays (24 cables)
that were connected almost at random.

Then I used glabel(8) to label the entire disk, and things were much
better.  But that didn't always play well with 4K drives, and replacing
drives that were the same size didn't always work as the number of sectors
in each disk was different (ZFS plays better with this now).

Then I started to GPT partition things, and life has been so much simpler.
All the partitions are aligned to 1 MB, and I can manually set the size of
the partition to work around different physical sector counts.  All the
partitions are labelled using the physical location of the disk (originally
just row/column naming like a spreadsheet, but now I'm adding enclosure
name as well as we expand to multiple enclosures per system).  It's so much
simpler now, ESPECIALLY when I have to get someone to do something
remotely.  :)

​Everyone has their own way to manage things.  I just haven't seen any
better setup than labelling the drives themselves using their physical
location.​

-- 
Freddie Cash
fjwcash at gmail.com