Evicting Disks from 3PAR Array (dismisspd)

[3padm]

Hi,

We have an F400 array and wish to complely evict 4 failed disks from the NL disk group. Are there a set of commands we can run to 'spin down' the disks and have them completly out of the array ?

Here is the output from 'showpd -c' on the failed disks.

3PAR-001 cli% showpd -c 13 22 28 40
                             ------- Normal Chunklets -------- ---- Spare Chunklets ----
                             - Used - -------- Unused -------- - Used - ---- Unused ----
Id CagePos Type State  Total OK  Fail Free Uninit Unavail Fail OK  Fail Free Uninit Fail
13 1:1:0       NL   failed  3724  0     0    0      0    3318  297  0     0    0     0  109
22 1:13:0    NL   failed  3724  0     0    0   1460       0 2159  0     0    0     0  105
28 2:5:0       NL   failed  3724  0     0    0   1461       0 2156  0     0    0     0  107
40 3:5:0      NL   failed   3724  0     0    0      0    3610    6  0     0    0     0  108
----------------------------------------------------------------------------------------
 4 total               14896  0     0    0   2921    6928 4618  0     0    0 

Thanks

[Dennis Handly]

>We have an F400 array and wish to completely evict 4 failed disks from the NL disk group.

I was going to suggest you look at this topic for instructions on how to do servicemag but I see it's yours:

http://h30499.www3.hp.com/t5/Storage-Area-Networks-SAN/Adding-new-disks-to-3PAR-System/m-p/6164679

So what's the current status and how come you weren't able to replace the disks?

Have you talked to Support yet?

Basically the command to remove a PD is dismisspd.  But in practice it is not obvious what you need to do first.

1) You have to permanently move off the used chunklets

2) You have to remove the spares on the PD. (easy and quick)

[3padm]

Hi,

Long story but It looks like the array looks at the caddys WWN rather than the disks so when we replace the disk - by putting it in the same caddy, the array does not care and still shows the caddys wwn thinking its the same old broken disk. We did have support on this array but it expired so we need to do it the long way. Have many other 3Pars but this one is only for Dev/Backups but still need to get it in a stable state.

So in the short term we thougth we'd evict the 4 failed disks and change the sparing algorithum from 'minimum' to 'default' but the array doesnt like to change this policy since it is already in an unstable state.

So what would be the commands to get say disk 3:5:0 out cleanly? 

Thanks

[Torsten.]

>> Long story but It looks like the array looks at the caddys WWN rather than the disks



We discussed this in your other thread already!


There is NO "caddy WWN"!

I still guess you used unsupported disk as a replacement.

Such replacement may even fail if the system firmware is too old to recognize newer disk firmware.

[Dennis Handly]

>but It looks like the array looks at the caddy's WWN

Did you ever provide the "showcage -d" output that I requested?  (While the new disk was inserted?)

>We did have support on this array but it expired so we need to do it the long way.

Hopefully you'll reconsider.  There may be something wrong with the loop to that magazine.

All the cases I put in an unsupported disk, showed the new WWN, serial, vendor and model.

> change the sparing algorithm from 'minimum' to 'default'

What command are you using to change it?

 >So what would be the commands to get say disk 3:5:0 out cleanly?

I'll have to check my notes for step 1).  2) is just removespare.
 

>There is NO "caddy WWN"!

Especially not in an F class.  For T and V, there is a bridge to enable SAS drives but I wasn't aware it had a WWN?

>Such replacement may even fail if the system software is too old

3.1.2 should be new enough.  But there is MU2.

[Torsten.]

Now I understand what you are trying to tell.

The disk chassis has a fibre channel interface, but all the SSD, SATA and SAS disks used in the array have not.

They have an adapter to "translate" to fibre channel and this has a WWN.

Consider to see this adapter as part of the disk!

You exchanged the disk only, you kept the adapter, right? This is your "caddy WWN".

From the system point of view there is still the same old disk, because there is still the same adapter with the same WWN.

You need an original spare part including caddy, adapter and disk.

I already sent you the part numbers.

Otherwise you may try a "dissmisspd", maybe this may help to remove the disk without replacement.

Another option could be to "unfail" the disk - you need to discuss this with 3par support.

[Dennis Handly]

>They have an adapter to "translate" to fibre channel and this has a WWN.

Well for SAS in T and V, it's called a bridge.  :-)  And it's part of the magazine.

>You exchanged the disk only, you kept the adapter, right? This is your "caddy WWN".

Using the bridge, you see one of the 4 WWNs from the SAS disk.

>you may try a "dismisspd", maybe this may help to remove the disk without replacement.

You'll quickly find it's easier said than done.  :-)

[Torsten.]

>> You'll quickly find it's easier said than done. :-)

For the system the data from the bad disk is still spared, not in a final position.

The bad disks are still bad, missing.

In other words, data still belongs to the bad disk.

The data needs to be moved permanently, not only spared.

I added the suggestion again to discuss this with 3par support.

But I think they will suggest to use an "original" spare part ... try to call them anyway.

[Dennis Handly]

>So what would be the commands to get say disk 3:5:0 out cleanly?

>Id CagePos Type State  Total OK  Fail Free Uninit Unavail Fail OK  Fail Free Uninit Fail

>40 3:5:0        NL    failed    3724  0      0        0      0             3610    6      0     0        0        0     108

This is PD 40.

(Swapping my original ordering)

1) To remove the spares from PD 40:

    removespare 40:a

2) To move the chunklets permanently off of PD 40, you need to first find them:

   showpdch -mov -from 40

Please provide the output of the showpdch command so I can make sure my script first works.

(This may be a big list, so you should attach as a .txt file.)

Also, you can now try the "dismisspd 40" to see what errors you get.

[Dennis Handly]

>I added the suggestion again to discuss this with 3par support.

Exactly.

>But I think they will suggest to use an "original" spare part ... try to call them anyway.

One suggestion is to try to add that disk in a new slot to just see if the system recognizes it.

(But don't do anything else besides "showpd -i".)

This isolates any problems with servicemag or the old slot/loop.