Unsolved
This post is more than 5 years old
29 Posts
0
3298
October 22nd, 2016 00:00
PS6610 with RAID 6 Accelerated
Hi,
we have recently deployed a PS6610 Array with 14 ssd drives and 70 NLSAS drives. Our understanding is that auto tiering will occur within the same enclosure on the different HDD types.
All is working fine but we would like to know were the data is residing, i.e percentage on SDD and percentage on NL-SAS, and possibly the hot volumes and cold volumes.
I have looked through group manager but I do not seem to be able to find this information.
Am I missing something or do I need to use other tools to view this information,
We would also like to prioritize SSD access to some volumes. is this possible?
accelerated
No Events found!
BriFar
29 Posts
0
October 24th, 2016 01:00
Hi,
Thank you for the reply. I accept that it cannot be set and I am sure DELL/Equallogic have their reasons.
I do not mean to be rude but understand why would the array move hot blocks to the SDD when, as you say, it would be faster to read from the NL-SAS Drives.
If the volume is tuned properly, from within the OS/hypervisor/VM and SAN, SSDs should provide higher IOPS than the NL-SAS. In fact the array will migrate the hot blocks to SSD for this purpose.
For clarity, I would want a volume to reside or prioritize placement on SSDs for systems that run a batch process once a week and would not want the storage to be the bottleneck.
In some hybrid systems you can allocate a percentage of read/write SSD cache to a volume which would help in the above.
Brian
BriFar
29 Posts
0
October 25th, 2016 07:00
Hi Donald,
I know what you are saying and I appreciate it. The argument, of wasting fast resource for idle data, also holds when you have multiple enclosures in the storage pool with different RAID sets and you assign a volume a preferred RAID set which is the fastest in the pool.
In that manner you can see how blocks are spread across the storage pool members which is good. Just thought I could see the same because I thought the same auto tiering mechanism existed.
Sometimes what looks like wasted resources to us would be resources reserved for when they are really needed for the customer. Yes they might increase the cost but could be operationally cheaper.
The main purpose of the thread was to understand better how the enclosure works and what visibility I have on the GUI.
Thank you for your responses.