[Info-vax] HSZ70 drive replacement question

[sapienzaf]

On Sep 28, 5:08 pm, Rich Jordan <jor... at ccs4vms.com> wrote:
> I don't have access to a test system, and haven't touched an HSZ since
> working on an HSZ40 10 years ago; I have HSZ40 docs and the CLI and
> service manual for the HSZ70 being reviewed now.  The units are dual
> HSZ70s in dual-redundant config, HSOF V73Z-0.
>
> Is there a 'best practices' or how-to doc for drive replacement?  The
> manuals seem to be somewhat conflicting (with the years between them
> unsurprising).  Two drive mirrorset with drives on separate channels.
> We want to replace a drive throwing occasional errors with a new unit,
> without involving the spareset drives.
>
> One manual (the HSZ40) says to quiesce the channel the drive is on
> using the button; replace the drive within 30-40 seconds and the
> controller will bring the new drive into the mirrorset and copy to it.
>
> Another says to use the CLI to reduce the mirrorset by removing the
> bad drive (but doesn't reduce automatically bring in a spareset
> drive?) then pull and replace the drive, then re-add the drive to the
> mirrorset.
>
> So what would be the proper method of doing this drive replacement?
> When it happens we'll have solid backups and full access to the HSZ
> consoles.
>
> Thanks
>
> Rich

Off the top of my head, syntax might not be right ...

Step 1:
HSZ> SET MIRROR <whatever> NOPOLICY

This tells the controller not to automatically spare in a drive.

Step 2:
HSZ> REDUCE <disk whatever>

Removes the bad disk from the mirror set.

Step 3:
Replace the bad disk with a good one.  I prefer quiescing the channel
by pushing the little button and waiting for the lights to start
flashing.  They are hot-swappable, though.

Step 4:
HSZ> SET MIRROR <whatever> REPLACE=<disk whatever>

That puts the good disk back into the mirror set and begins copying.

Step 5:
HSZ> SET MIRROR <whatever> POLICY=<pick BEST_PERFORMANCE or BEST_FIT>

This tells the controller to allow auto-sparing on that mirror set
again.