Unsolved
This post is more than 5 years old
242 Posts
0
2002
October 24th, 2014 15:00
Can we carve Luns with large size or small size ???
We have a request to create 5TB Lun on CX4/VMAX. Is it best practise to create luns with bigger size.
No Events found!
dynamox
9 Legend
•
20.4K Posts
0
October 24th, 2014 20:00
what is this LUN for ?
Anonymous User
242 Posts
0
October 26th, 2014 19:00
This Lun is for SQL databases.
dynamox
9 Legend
•
20.4K Posts
0
October 26th, 2014 19:00
review Microsoft best practices for SQL layout, you don't want one drive. You want at least one drive for logs and one for database files.
Anonymous User
242 Posts
0
October 26th, 2014 19:00
That's right.
For every drive they are requesting more than 1.5TB.
They are ready to change those Luns to small sizes. But not sure whether bigger or smaller size will be a best practice
Anonymous User
242 Posts
0
October 26th, 2014 19:00
This is on clarion we have unbound SAS drives.
For some database Luns are Raid 10 & some are Raid 5.
They are requesting for 5tb Lun.
I am thinking small chucks will be good for performance and sizes.
Roger_Wu
4 Operator
•
4K Posts
0
October 26th, 2014 19:00
What's your requirement? Performance or storage efficiency?
I think disk types, RAID types, traditional LUN (metaLUN) or Pool LUN are more important than LUN size...
You can take a look at http://www.emc.com/collateral/hardware/white-papers/h5773-clariion-best-practices-performance-availability-wp.pdf
dynamox
9 Legend
•
20.4K Posts
1
October 26th, 2014 20:00
design for performance first, then capacity. Make sure LUNs you create will meet their I/O requirements. There is not as much tweaking you can do on VMAX as opposed to Clariion with traditional raid groups.
kelleg
4.5K Posts
1
October 27th, 2014 13:00
With databases you usually have three types of LUNs:
1. database - this typically is configured using a Raid 5 LUN
2. Temp and Logs - these are usually configured using Raid 10
You want to separate the database files from the Temp and Logs in different raid groups.
I've attached a SQL document - this is for the VNX, but the general rules for the different types of raid groups apply to the CX4 - see page 25, Table 7. Caution, do not enable FAST Cache on the LUNs used for the Logs and Temp (or on the Pools containing these LUNs if you're using Pools).
Also, the CX4 uses Fibre Channel disks, the VNX uses SAS disks.
glen
1 Attachment
docu51361_White-Paper_-Enhancing-the-Performance-and-Protection-of-Microsoft-SQL-Server-2012.pdf
Anonymous User
242 Posts
0
October 27th, 2014 13:00
Thank You for the white paper document. I will go through it and revert back if any question.
Is there any reason that we should not enable fast cache on Temp and Logs Lun Pools.
kelleg
4.5K Posts
1
October 27th, 2014 14:00
The IO pattern for Logs and Temp do not work well with SSD drives. But for database files, FAST cache is very useful.
Please see the two Knowledgebase articles below for additional information.
https://support.emc.com/kb/84362 CLARiiON and VNX: Where do I find information about FAST Cache?
https://support.emc.com/kb/73184 FAST Cache configuration best practices
glen
Anonymous User
242 Posts
0
November 7th, 2014 08:00
I have created Luns as per SQL Database best practice.
Thanks a lot for you help. Documents which you forwarded are very helpful.