asked on

EMC CX SAN IO Performance issues

Hello EE,

I need expert advise fast. We are rolling out Microsoft Dynamics and it is currently on an EMC CX 4120 and performance is slow

Read Rand IOPS       Read Rand MBps       Write Rand IOPS       Write Rand MBps       Read Seq IOPS       Read Seq MBps       Write Seq IOPS       Write Seq MBps
CX SQL Data (RAID5)       2856.28       22.31       786.57       6.14       16742.91       130.8       561.69       4.38
CX SQL Log (RAID 1+0)       1726.54       13.48       763.36       5.96       18085.56       141.29       3561.35       27.82
VNX SSD RAID5 (TEST01)       22036.2       172.15       13235.9       103.4       19576.9       152.94       15733.4       122.91
VNX RAID5 (BUILD01)       61369.34       479.44       100.53       0.78       66381       518.6       10759.17       84.05

We’re being asked to dramatically increase SQL IO performance by the end of this week. And adding 6TB of RAM, and trading in/buying a new SAN isn’t an option. Intra-business day downtime for SQL is an option. The SSD (have 5) seem to be performing, suggestions?

Thanks!

Duncan Meyers

These are absolutely amazing performance numbers for a CX4-120 (assuming your numbers are accurate)
This one in particular is HUGE:

VNX RAID5 (BUILD01) Read IOPS: 61369.34 Read MB/s: 479.44

If you really are pushing that sort of I/O through a CX4-120 then pat yourself on the back.

Can you post response times for
CX SQL Data (RAID5)
CX SQL Log (RAID 1+0)
VNX SSD RAID5 (TEST01)
VNX RAID5 (BUILD01)
please?
Ideally, can you use Unisphere Analyzer?
Also, please check Storage Processor CPU utilisation.

bergquistcompany

ASKER

Is the CX a lower performing unit then the VNX 5300? I am concerned in the IOPS between the 2? CX seems extremely slow?

I can run the Unisphere Analyzer, but don't know how to read it without EMC support.

Here is the CX report wizard statistics

Read Cache State Enabled both SP
Write Cache State Disabled both SP
Mirrored Write Cache Enabled both SP
Free Memory 66MB
Read Cache Size 529 MB
Write Cache Size 3 MB
Cache Page Size 4 kb
Lower 60% Watermark
High 80% Watermark
HA Cache Valut Disabled
Opt Raid 3 memory 0MB

Duncan Meyers

>Is the CX a lower performing unit then the VNX 5300? I am concerned in the IOPS between the 2? CX seems extremely slow?
Well, yes. The VNX is a generation newer and significantly faster. However, the perofrmance numbers are meaningless without response times in mS and understanding how the array is configured and how many drives are in the LUNs. A CX4-120 is theoretically capable of more than 20,000 IOPS with enough disks and configured for performance, so it's still pretty capable

bergquistcompany

ASKER

No, the CX should be able to do what the VNX does and the VNX is a 1Mb iSCSI and the CX 4Mb fiber which I think would impact as well. I hear your thoughts is there a better way to measure?

ASKER CERTIFIED SOLUTION

Duncan Meyers

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

Duncan Meyers

Strewth. That was a long post. :-)

bergquistcompany

ASKER

Great post thanks!