Based on that, I would not bother setting up a cache partition on the VMAX. If the data is active, it will be in cache anyway.
There is a feature in Symmetrix that allows you to setup cache partitions and put devices into them, without actually enforcing the limits. This along with DCP partition stats can give you insight into how much cache a group of volumes is using without impacting performance. You could do this on the DMX4, as long as you are running at least 5772 code or higher.
I also am generally against isolating things from one another unless there is a really good reason. You will get the best performance from the Symm if you don't isolate disks, cache, engines, etc from one another. However there are some very strong cases for isolation, such as backup to disks where the disks are SATA and RAID6. That is a perfect case for DCP.
1st question is why you want to put this application in a partition in the first place. The answer may help to figure out the size.
Is the application already running on the Symm? If so, and if you don't already have DCP running, you could use analysis mode to see how much cache it is using.
If the DCP is already enabled, you could put those LUNs into a flexible partition ( min =0 target = x max =100 time = 300 ) and see how much it uses.
This application already runs on a Symmetrix DMX4, thick provisioned and with dedicated diskgroup (dedicated hdd)
We need to migrate it in a "very shared" environment (a thin provisioned VMAX) so that we thought about a simple way to assure a medium-high level of performance.
Quincy561
1.3K Posts
0
December 22nd, 2011 05:00
Based on that, I would not bother setting up a cache partition on the VMAX. If the data is active, it will be in cache anyway.
There is a feature in Symmetrix that allows you to setup cache partitions and put devices into them, without actually enforcing the limits. This along with DCP partition stats can give you insight into how much cache a group of volumes is using without impacting performance. You could do this on the DMX4, as long as you are running at least 5772 code or higher.
I also am generally against isolating things from one another unless there is a really good reason. You will get the best performance from the Symm if you don't isolate disks, cache, engines, etc from one another. However there are some very strong cases for isolation, such as backup to disks where the disks are SATA and RAID6. That is a perfect case for DCP.
Quincy561
1.3K Posts
1
December 22nd, 2011 04:00
1st question is why you want to put this application in a partition in the first place. The answer may help to figure out the size.
Is the application already running on the Symm? If so, and if you don't already have DCP running, you could use analysis mode to see how much cache it is using.
If the DCP is already enabled, you could put those LUNs into a flexible partition ( min =0 target = x max =100 time = 300 ) and see how much it uses.
Ninja73
8 Posts
0
December 22nd, 2011 05:00
Many thanks
Ninja73
8 Posts
0
December 22nd, 2011 05:00
Hi Quincy56,
This application already runs on a Symmetrix DMX4, thick provisioned and with dedicated diskgroup (dedicated hdd)
We need to migrate it in a "very shared" environment (a thin provisioned VMAX) so that we thought about a simple way to assure a medium-high level of performance.
What do you mean for "analisys mode"?
Quincy561
1.3K Posts
0
December 22nd, 2011 06:00
Good luck, let us know if you have any other questions.