Hello Toasters,
We have a FAS3170 HA pair with some SATA disk shelves (AT-FCX) attached to the end of a chain where none of the disks are in use (all are spares, all have ownership assigned). We are running ONTAP 8.0.1.
The chain is singly attached to both controllers, i.e., the shelf "A" modules are chained to a single FC adapter on one controller and the shelf "B" modules are chained to a single FC adapter on the other controller.
The shelves we want to remove are at the far end of the chain. Essentially we want to undo the result of a hot shelf add without downtime.
Is it possible to hot remove these shelves? Would it help to "un-own" the disks first?
I suppose this could be done using CF takeover/giveback but that might be too disruptive.
Steve Losen scl@virginia.edu phone: 434-924-0640
University of Virginia ITC Unix Support
AFAIK there is no official way to do this without downtime.
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Steve Losen Sent: 02 June 2011 14:03 To: toasters@mathworks.com Subject: Hot remove disk shelves?
Hello Toasters,
We have a FAS3170 HA pair with some SATA disk shelves (AT-FCX) attached to the end of a chain where none of the disks are in use (all are spares, all have ownership assigned). We are running ONTAP 8.0.1.
The chain is singly attached to both controllers, i.e., the shelf "A" modules are chained to a single FC adapter on one controller and the shelf "B" modules are chained to a single FC adapter on the other controller.
The shelves we want to remove are at the far end of the chain. Essentially we want to undo the result of a hot shelf add without downtime.
Is it possible to hot remove these shelves? Would it help to "un-own" the disks first?
I suppose this could be done using CF takeover/giveback but that might be too disruptive.
Steve Losen scl@virginia.edu phone: 434-924-0640
University of Virginia ITC Unix Support
To report this email as spam click https://www.mailcontrol.com/sr/wQw0zmjPoHdJTZGyOCrrhg== .
Member of the CSR plc group of companies. CSR plc registered in England and Wales, registered number 4187346, registered office Churchill House, Cambridge Business Park, Cowley Road, Cambridge, CB4 0WZ, United Kingdom More information can be found at www.csr.com. Follow CSR on Twitter at http://twitter.com/CSR_PLC and read our blog at www.csr.com/blog
I've seen people do this without problems, but I've not had to do it yet myself. Having the disks unassigned is a good idea since you'll want them unowned when you add them to other heads. If you can afford to do it while in takeover mode that probably couldn't hurt.
Let us know how it goes. I'm under the impression this works, but is unsupported from netapp eng still.
-Blake
On Thu, Jun 2, 2011 at 6:03 AM, Steve Losen scl@sasha.acc.virginia.edu wrote:
Hello Toasters,
We have a FAS3170 HA pair with some SATA disk shelves (AT-FCX) attached to the end of a chain where none of the disks are in use (all are spares, all have ownership assigned). We are running ONTAP 8.0.1.
The chain is singly attached to both controllers, i.e., the shelf "A" modules are chained to a single FC adapter on one controller and the shelf "B" modules are chained to a single FC adapter on the other controller.
The shelves we want to remove are at the far end of the chain. Essentially we want to undo the result of a hot shelf add without downtime.
Is it possible to hot remove these shelves? Would it help to "un-own" the disks first?
I suppose this could be done using CF takeover/giveback but that might be too disruptive.
Steve Losen scl@virginia.edu phone: 434-924-0640
University of Virginia ITC Unix Support
It may appear to work at first, but you'll have a panic and crash eventually. It might last a week or two, but you'll eventually have problems.
If you move quick and you have your FC/NFS timeouts set right, you can shut down, decable the shelves, and turn it back on before hosts will notice. I've done that myself more than a few times.
-----Original Message----- From: Blake Golliher [mailto:thelastman@gmail.com] Sent: Thursday, June 02, 2011 3:07 PM To: Steve Losen Cc: toasters@mathworks.com Subject: Re: Hot remove disk shelves?
I've seen people do this without problems, but I've not had to do it yet myself. Having the disks unassigned is a good idea since you'll want them unowned when you add them to other heads. If you can afford to do it while in takeover mode that probably couldn't hurt.
Let us know how it goes. I'm under the impression this works, but is unsupported from netapp eng still.
-Blake
On Thu, Jun 2, 2011 at 6:03 AM, Steve Losen scl@sasha.acc.virginia.edu wrote:
Hello Toasters,
We have a FAS3170 HA pair with some SATA disk shelves (AT-FCX) attached to the end of a chain where none of the disks are in use (all are spares, all have ownership assigned). We are running ONTAP 8.0.1.
The chain is singly attached to both controllers, i.e., the shelf "A" modules are chained to a single FC adapter on one controller and the shelf "B" modules are chained to a single FC adapter on the other controller.
The shelves we want to remove are at the far end of the chain. Essentially we want to undo the result of a hot shelf add without downtime.
Is it possible to hot remove these shelves? Would it help to "un-own" the disks first?
I suppose this could be done using CF takeover/giveback but that might be too disruptive.
Steve Losen scl@virginia.edu phone: 434-924-0640
University of Virginia ITC Unix Support
On 2011 Jun 2, at 16:45 , Steiner, Jeffrey wrote:
It may appear to work at first, but you'll have a panic and crash eventually. It might last a week or two, but you'll eventually have problems.
I accidentally removed a shelf full of unowned disks once from a production machine, and that worked without a (technical) problem. It is however unsupported by netapp, so I got mildly grilled by my coworkers for putting a production filer in danger.
In this case, the shelf I removed was the only one on that loop. That might make things slightly "better", but I don't know for sure.
You definitely want to unown the disks first, regardless of whether you power down or not.
Note that takeover isn't going to help. At least not in the normal takeover situation. Both partners see the same disks, so the one that's still up still sees a shelf disappearing.
Powering down seems to me like your only (supported) option.
If you move quick and you have your FC/NFS timeouts set right, you can shut down, decable the shelves, and turn it back on before hosts will notice. I've done that myself more than a few times.
-----Original Message----- From: Blake Golliher [mailto:thelastman@gmail.com] Sent: Thursday, June 02, 2011 3:07 PM To: Steve Losen Cc: toasters@mathworks.com Subject: Re: Hot remove disk shelves?
I've seen people do this without problems, but I've not had to do it yet myself. Having the disks unassigned is a good idea since you'll want them unowned when you add them to other heads. If you can afford to do it while in takeover mode that probably couldn't hurt.
Let us know how it goes. I'm under the impression this works, but is unsupported from netapp eng still.
-Blake
On Thu, Jun 2, 2011 at 6:03 AM, Steve Losen scl@sasha.acc.virginia.edu wrote:
Hello Toasters,
We have a FAS3170 HA pair with some SATA disk shelves (AT-FCX) attached to the end of a chain where none of the disks are in use (all are spares, all have ownership assigned). We are running ONTAP 8.0.1.
The chain is singly attached to both controllers, i.e., the shelf "A" modules are chained to a single FC adapter on one controller and the shelf "B" modules are chained to a single FC adapter on the other controller.
The shelves we want to remove are at the far end of the chain. Essentially we want to undo the result of a hot shelf add without downtime.
Is it possible to hot remove these shelves? Would it help to "un-own" the disks first?
I suppose this could be done using CF takeover/giveback but that might be too disruptive.
Steve Losen scl@virginia.edu phone: 434-924-0640
University of Virginia ITC Unix Support
-
Blake Golliher -
Darren Sykes -
Jan-Pieter Cornet -
Steiner, Jeffrey -
Steve Losen