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Dedupe and compression on all flash 8200
https://3parug.com/viewtopic.php?f=18&t=3482		 Page 1 of 1
Author:  adamdb [ Wed Oct 14, 2020 4:42 am ]
Post subject:  Dedupe and compression on all flash 8200
Hi all,
I have a customer with an 8200 (single unit with 16x 1.92tb ssd drives). Currently all data resides in a single raid 6 cpg (6+2). With a mix of VV types. About 40% of the vols are thin/dedupe and the remainder simply thin. The thin/dedupe are serving VDI infrastructure over VMWARE and the remainder just vanilla vmware estate. So nothing fancy. So they have around 19tb useable.

I am debating whether to enable dedupe for all volumes given it's primarily windows 2012 and 2016 estate.. and perhaps even compression on some of them.

CPU use on the array is low right now (10-15%) so there is headroom from a CPU point of view to enable compression and make some further space savings. I know compression is a double hit in terms of impact as both reads and writes need to dealt with.

I did do a dry run against the thin only vols and seems like we'd see some nice savings.


2020-10-13 10:44:32 GMT Started checkvv space estimation started with option -dedup_compr_dryrun

2020-10-13 19:41:49 GMT Finished checkvv space estimation process finished

-(User Data)- -(Compression)- -------(Dedup)------- -(DataReduce)-

Id Name Size(MB) Size(MB) Ratio Size(MB) Ratio Size(MB) Ratio
2 INF_DS01 900210 600140 1.50 -- -- 600140 1.50
5 INF_DS02 1190341 868863 1.37 -- -- 868863 1.37
14 INF_DS03 1995738 1797962 1.11 -- -- 1797962 1.11
15 INF_DS04 3383867 2892195 1.17 -- -- 2892195 1.17
16 INF_DS05 1546583 1247245 1.24 -- -- 1247245 1.24
-----------------------------------------------------------------------------
5 total 9016741 7451853 1.21 6261626 1.44 5367108 1.68

I have another customer (also on an 8200) running with 32x3.84tb but using compression and dedupe (sometimes both) across the board and CPU sits at around 50%. No noticeable performance problems but SSMC does warn about saturation periodically. But this customer do leverage the array quite hard.

Anyway just seeking opinions...

thanks.
Author:  MammaGutt [ Wed Oct 14, 2020 6:29 am ]
Post subject:  Re: Dedupe and compression on all flash 8200
What 3PAR OS version (and DDS version)?

My general thought is "what is the customer looking for?"

If performance is the number one priority, then everything goes thin.
If they are at a point where they think they might run out of capacity before the system has reached the end of its lifecycle and cost is a factor, then go data reduction (dedupe or deco).

If the customers previous storage array was a small system with 30-40x 10k/15k drives, then you can probably do whatever you want with the 3PAR and it will never perform less :)

Just keep in mind. Any data reduction technology requires you to have a little bit more head room in the system as it will have to do more cleanup in the background. If you're running out of capacity and need to take steps to free capacity, you usually need both more capacity and more time (resulting in even more capacity) than if you were doing simple thin (of full) volumes.
Author:  adamdb [ Wed Oct 14, 2020 8:35 am ]
Post subject:  Re: Dedupe and compression on all flash 8200
MammaGutt wrote:
What 3PAR OS version (and DDS version)?

My general thought is "what is the customer looking for?"

If performance is the number one priority, then everything goes thin.
If they are at a point where they think they might run out of capacity before the system has reached the end of its lifecycle and cost is a factor, then go data reduction (dedupe or deco).

If the customers previous storage array was a small system with 30-40x 10k/15k drives, then you can probably do whatever you want with the 3PAR and it will never perform less :)

Just keep in mind. Any data reduction technology requires you to have a little bit more head room in the system as it will have to do more cleanup in the background. If you're running out of capacity and need to take steps to free capacity, you usually need both more capacity and more time (resulting in even more capacity) than if you were doing simple thin (of full) volumes.



Customer is on 3.3.1 MU3 with patches going to MU5 with whatever latest patches are. Cost will be a factor so I am thinking it's better to think about data reduction of vols when the system has plenty of headroom (just under 70% used right now) rather than trying to do it when they are in more dire straits and running low!
I doubt they'd notice any performance difference as it's only providing storage to 8 x DL360's over 10GB ISCSI. Average 24 saturation figure is 9%.


thanks.
Author:  MammaGutt [ Wed Oct 14, 2020 9:26 am ]
Post subject:  Re: Dedupe and compression on all flash 8200
Average saturation is a dangerous number. If the system is at 100% for 2 hours and pretty much idle for the rest of the day, you could have 9% saturation :)

Also, in many environments it's backup at night that puts the most load onto the system :)

I would get it up to MU5 pretty soon as MU3 goes inactive any day now (was Nov 1st?)


Did you check for compression? In many cases I see compression providing equal or better reduction than dedupe. Compression is usually good or non-existing.

Just remember to follow best practice with Vmware. Thick Eager Zero for VMFS5, thin (and VM hardware version 11 or above) with VMFS6 that supports automatic unmap. VMFS6 might provide more savings than dedupe if you have a dynamic environment and use vmware snapshots for backup.
Author:  cali [ Sat Oct 24, 2020 1:58 pm ]
Post subject:  Re: Dedupe and compression on all flash 8200
adamdb wrote:
I am debating whether to enable dedupe for all volumes given it's primarily windows 2012 and 2016 estate.. and perhaps even compression on some of them.

Anyway just seeking opinions...

thanks.


Keep in mind, that dedup is mostly done by the ASIC and need only low CPU.
Compression is a high CPU intense task.

I use always dedup and no compression.
Compression is good for Databases, but they have small Volumes and need high performance.

Cali
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