Greetings,
I have a FAS3040 running 7.2.4 that is used primarily for LUNs over FCP. I balance most of the filesystems across four LUNs in two volumes groups spread across both controllers. I would like to add additional space, but was wondering if there were best practices in terms of buying two shelves at a time (like some other vendor's models) or if a single shelf is okay. Since I spread the space across both controllers, is it okay to distribute the disks on a single shelf to both controllers? Will this affect RGs or performance in any way?
TIA,
Daniel
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We added two DS14 shelves (seperately about 6 months apart) and allocated the disks in each shelf to different controllers so what you're asking is perfectly OK to do - add disks to whichever controller you like and theres no requirement to add shelves in pairs.
Cheers, Raj.
On Wed, Jul 9, 2008 at 5:52 AM, Daniel Keisling daniel.keisling@austin.ppdi.com wrote:
Greetings,
I have a FAS3040 running 7.2.4 that is used primarily for LUNs over FCP. I balance most of the filesystems across four LUNs in two volumes groups spread across both controllers. I would like to add additional space, but was wondering if there were best practices in terms of buying two shelves at a time (like some other vendor's models) or if a single shelf is okay. Since I spread the space across both controllers, is it okay to distribute the disks on a single shelf to both controllers? Will this affect RGs or performance in any way?
TIA, Daniel
This email transmission and any documents, files or previous email messages attached to it may contain information that is confidential or legally privileged. If you are not the intended recipient or a person responsible for delivering this transmission to the intended recipient, you are hereby notified that you must not read this transmission and that any disclosure, copying, printing, distribution or use of this transmission is strictly prohibited. If you have received this transmission in error, please immediately notify the sender by telephone or return email and delete the original transmission and its attachments without reading or saving in any manner.
Hi Daniel,
On Tue, Jul 8, 2008 at 7:52 PM, Daniel Keisling < daniel.keisling@austin.ppdi.com> wrote:
Greetings,
I have a FAS3040 running 7.2.4 that is used primarily for LUNs over FCP. I balance most of the filesystems across four LUNs in two volumes groups spread across both controllers. I would like to add additional space, but was wondering if there were best practices in terms of buying two shelves at a time (like some other vendor's models) or if a single shelf is okay. Since I spread the space across both controllers, is it okay to distribute the disks on a single shelf to both controllers? Will this affect RGs or performance in any way?
The only best practice that I can think of that may apply here for a clustered configuration, is to always add more than 3 disks to a rg at one time, to prevent hotspots in your raid and thus performance loss.
Also, if you are running a configuration with syncmirror (such as a metrocluster), your configuration may be a bit more complex and you would have to split the disks not only over the heads, but also over the pools. In this configuration adding a single shelf usually results in low net space being added, since the disks are split 4 ways, resulting in 3 - 4 disks per rg, so I would recommend to add at least two shelves when expanding a metrocluster.
HTH & HAND
Nils.
-
Daniel Keisling -
Nils Vogels -
Raj Patel