HPE Storage Users Group

A Storage Administrator Community




Post new topic Reply to topic  [ 4 posts ] 
Author Message
 Post subject: Space reclaim on shared space in CPG
PostPosted: Fri Jun 28, 2019 11:29 pm 
User avatar

Joined: Wed Aug 26, 2015 5:32 am
Posts: 3
Hi folks,

we are implementing a new all-flash 3PAR 8400.

For test purposes we deleted all volumes of a CPG except one, to check if the space reclaim process of the shared space (dedup) is working.

Unfortunately the amount of data in the shared space remained exactly the same, even after a "compact cpg". The shared space of the CPG is now mutch bigger then the last volume on it. Is there a option which we miss?

If not, how do you deal with this issue? For example, after some time you have big appliactions with good dedup-results which are going to be replaced. If the shared space is never cleaned up, its only getting bigger. Do you on regular basis recreate the CPGs and do you use more than one CPG to seperate the applications?

Out first idea was to use only one CPG for the best dedup-results, it seams not a good idea if we have to recreate it.

Best regards,
fcguy


Top
 Profile  
Reply with quote  
 Post subject: Re: Space reclaim on shared space in CPG
PostPosted: Sat Jun 29, 2019 3:08 am 

Joined: Mon Sep 21, 2015 2:11 pm
Posts: 1570
Location: Europe
What 3PAR OS?

Tdvv2 (dedupe cpg created on 3.2.2) it would take ages.
Tdvv3 (dedupe cpg created on 3.3.1) works better.

There are some recleam bugs fixed in 3.3.1 MU2 P76 and 3.2.2 MU6 P144 if I recall correctly so unless you're using latest and greatest those might be an issue for you.

_________________
The views and opinions expressed are my own and do not necessarily reflect those of my current or previous employers.


Top
 Profile  
Reply with quote  
 Post subject: Re: Space reclaim on shared space in CPG
PostPosted: Sat Jun 29, 2019 3:21 am 
User avatar

Joined: Wed Aug 26, 2015 5:32 am
Posts: 3
MammaGutt wrote:
What 3PAR OS?

Tdvv2 (dedupe cpg created on 3.2.2) it would take ages.
Tdvv3 (dedupe cpg created on 3.3.1) works better.

There are some recleam bugs fixed in 3.3.1 MU2 P76 and 3.2.2 MU6 P144 if I recall correctly so unless you're using latest and greatest those might be an issue for you.


Hi MammaGutt,

thank you. We are using TDVV3 on 3.3.1 MU3 with patches P50/58/61/77/78, so I think the patches you mentioned should be included.

You are sure that there is a space reclaim process for the "shared space" area of a CPG? Can this process manualy be triggert?

Best regards,
fcguy


Top
 Profile  
Reply with quote  
 Post subject: Re: Space reclaim on shared space in CPG
PostPosted: Sat Jun 29, 2019 4:30 am 

Joined: Mon Sep 21, 2015 2:11 pm
Posts: 1570
Location: Europe
Can't be triggered manually.

Showeventlog -oneline -debug -msg "reclaim history" -min 1440
Should show any reclaim happening on all volumes. If you doesn't see anything there you should try
Showeventlog -oneline -debug -msg "cand" -min 1440
To see if it triggers a defrag due to lack of reclaim.

If you see no reclaim or defrag I would log a case.

_________________
The views and opinions expressed are my own and do not necessarily reflect those of my current or previous employers.


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 4 posts ] 


Who is online

Users browsing this forum: Google [Bot] and 34 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group | DVGFX2 by: Matt