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Spare space problem.
Posted: Fri Apr 21, 2023 12:26 am
by Morbo
Hello, guys.
We have two identical 3par 7200 systems in syncrronous replication (FC).
Both have 8 SDD 400GB and 8 SDD 480GB in different shelves. None of those in failed state. Health of both systems is good.
There two CPG on SSD disks (RAID6 (used exclusively for one vvol) and RAID5 (used in ao configuration for all another vvols)) CPGs and vvols on both systems have identical sizes (as all vvols on systems in sync replication))
There is a problem - first system have reserved 30% spare space on each SDD, but second have only 15%. This leads to overusage on SSD disks on first system, these are loaded up to 99% (second system is on 92)
Like this (showpd -space):
One system
Id CagePos Type -State- Size Volume Spare Free Unavail Failed
0 0:0:0 SSD normal 456704 336896 112640 7168 0 0
....
Another system
Id CagePos Type -State- Size Volume Spare Free Unavail Failed
0 0:0:0 SSD normal 456704 322560 62464 71680 0 0
How could we determine why first system reserved twice as much spare size than second system, and how could we recover it?
Thanks.
Re: Spare space problem.
Posted: Fri Apr 21, 2023 12:40 pm
by MammaGutt
Without knowing anything more than you say here, I would start by looking at «showsys -param» and check SparingAlgorithm parameter
Re: Spare space problem.
Posted: Sun Apr 23, 2023 11:54 pm
by Morbo
Thank you for reply.
Just checked "showsys -param" on both systems.
Sparing algorithm (as all other params) are exactly the same on both systems.
What additional information could help to determine this issue?
Code: Select all
------Parameter------ --Value---
RawSpaceAlertFC : 1024
RawSpaceAlertNL : 0
RawSpaceAlertSSD : 1024
RemoteSyslog : 0
RemoteSyslogHost : 0.0.0.0
SparingAlgorithm : Default
EventLogSize : 3M
VVRetentionTimeMax : 336 Hours
UpgradeNote :
PortFailoverEnabled : yes
AutoExportAfterReboot : yes
AllowR5OnNLDrives : no
AllowR0 : no
ThermalShutdown : yes
FailoverMatchedSet : yes
SessionTimeout : 01:00:00
HostDIF : no
DisableDedup : no
PersonaProfile : block-only
SingleLunHost : no
Re: Spare space problem.
Posted: Mon Apr 24, 2023 12:53 am
by MammaGutt
Because I'm lazy and don't have (or remember) the exact chunklet number for 400 and 480 GBs...
Can you share "showpd -c -p -devtype SSD" for both systems?
Re: Spare space problem.
Posted: Mon Apr 24, 2023 1:40 am
by Morbo
Sure.
See the difference in spare chunklets.
Code: Select all
3par-1-srvn cli% showpd -c -p -devtype SSD
-------- Normal Chunklets -------- ---- Spare Chunklets ----
- Used -- -------- Unused -------- - Used - ---- Unused ----
Id CagePos Type State Total OK Fail Free Uninit Unavail Fail OK Fail Free Uninit Fail
0 0:0:0 SSD normal 446 324 0 12 0 0 0 0 0 110 0 0
1 0:1:0 SSD normal 446 330 0 6 0 0 0 0 0 110 0 0
2 0:2:0 SSD normal 446 323 0 14 0 0 0 0 0 109 0 0
3 0:3:0 SSD normal 446 328 0 9 0 0 0 0 0 109 0 0
4 0:4:0 SSD normal 446 321 0 16 0 0 0 0 0 109 0 0
5 0:5:0 SSD normal 446 326 0 12 0 0 0 0 0 108 0 0
6 0:6:0 SSD normal 446 322 0 17 0 0 0 0 0 107 0 0
7 0:7:0 SSD normal 446 327 0 13 0 0 0 0 0 106 0 0
48 2:0:0 SSD normal 371 277 0 6 0 0 0 0 0 88 0 0
49 2:1:0 SSD normal 371 277 0 6 0 0 0 0 0 88 0 0
50 2:2:0 SSD normal 371 278 0 5 0 0 0 0 0 88 0 0
51 2:3:0 SSD normal 371 274 0 7 0 0 0 0 0 90 0 0
52 2:4:0 SSD normal 371 280 0 6 0 0 0 0 0 85 0 0
53 2:5:0 SSD normal 371 278 0 6 0 0 0 0 0 87 0 0
54 2:6:0 SSD normal 371 280 0 5 0 0 0 0 0 86 0 0
55 2:7:0 SSD normal 371 275 0 7 0 0 0 0 0 89 0 0
-----------------------------------------------------------------------------------------
16 total 6536 4820 0 147 0 0 0 0 0 1569 0 0
Code: Select all
3par-2-cpmz cli% showpd -c -p -devtype SSD
-------- Normal Chunklets -------- ---- Spare Chunklets ----
- Used -- -------- Unused -------- - Used - ---- Unused ----
Id CagePos Type State Total OK Fail Free Uninit Unavail Fail OK Fail Free Uninit Fail
0 0:0:0 SSD normal 446 315 0 70 0 0 0 0 0 61 0 0
1 0:1:0 SSD normal 446 316 0 69 0 0 0 0 0 61 0 0
2 0:2:0 SSD normal 446 317 0 68 0 0 0 0 0 61 0 0
3 0:3:0 SSD normal 446 315 0 70 0 0 0 0 0 61 0 0
4 0:4:0 SSD normal 446 316 0 69 0 0 0 0 0 61 0 0
5 0:5:0 SSD normal 446 316 0 69 0 0 0 0 0 61 0 0
6 0:6:0 SSD normal 446 317 0 68 0 0 0 0 0 61 0 0
7 0:7:0 SSD normal 446 314 0 71 0 0 0 0 0 61 0 0
48 2:0:0 SSD normal 371 320 0 0 0 0 0 0 0 51 0 0
49 2:1:0 SSD normal 371 320 0 0 0 0 0 0 0 51 0 0
50 2:2:0 SSD normal 371 320 0 0 0 0 0 0 0 51 0 0
51 2:3:0 SSD normal 371 320 0 0 0 0 0 0 0 51 0 0
52 2:4:0 SSD normal 371 321 0 0 0 0 0 0 0 50 0 0
53 2:5:0 SSD normal 371 321 0 0 0 0 0 0 0 50 0 0
54 2:6:0 SSD normal 371 321 0 0 0 0 0 0 0 50 0 0
55 2:7:0 SSD normal 371 321 0 0 0 0 0 0 0 50 0 0
-----------------------------------------------------------------------------------------
16 total 6536 5090 0 554 0 0 0 0 0 892 0 0
Re: Spare space problem.
Posted: Mon Apr 24, 2023 2:17 am
by MammaGutt
Double check that SparingAlgorithm is set to default on 3par-1-srvn.
If that is set to default, run "admithw" on the system to recreate spare capacity. The correct number of spare chunklets should be 892 (similar to the capacity of 2 drives per 24 SSDs).
Are both running the same 3PAR OS version?
Re: Spare space problem.
Posted: Mon Apr 24, 2023 4:39 am
by Morbo
Yes, systems are identical.
The only difference is that the system with normal spare size have adaptive flash cache enabled.
It went like this:
We`d decided to try to use AFC on both systems.
We succefully enabled it (256GB in size) on one system.
But on the other, it failed to enable with error "Could not find enough available disk space."
After that we started to investigate and found overusage of spare space on this system.
I`ve run admithw on 3par, but it has no effect.
Should i run tunesys also?
Re: Spare space problem.
Posted: Mon Apr 24, 2023 4:59 am
by MammaGutt
Morbo wrote:Yes, systems are identical.
The only difference is that the system with normal spare size have adaptive flash cache enabled.
It went like this:
We`d decided to try to use AFC on both systems.
We succefully enabled it (256GB in size) on one system.
But on the other, it failed to enable with error "Could not find enough available disk space."
After that we started to investigate and found overusage of spare space on this system.
I`ve run admithw on 3par, but it has no effect.
Should i run tunesys also?
If you compare "showpd -c" on both systems. Is it only the SSDs that have double spare capacity or is it the same for all drive types?
You could try and do "setsys SparingAlgorithm Minimal" and admithw again. It should reduce (but it should reduce it more than you want). Reduced sparing will allow for less hardware failure before you risk data loss.
Re: Spare space problem.
Posted: Mon Apr 24, 2023 5:15 am
by Morbo
Code: Select all
Type Drives Total chunks Spare(3par-1) Spare(3par-2)
FC 32 30960 1340 2232
NL 24 86664 4297 4990
SSD 16 6536 1569 892
On second system there is similar situation but with FC drives.
Re: Spare space problem.
Posted: Mon Apr 24, 2023 5:17 am
by Morbo
If I do like this:
Code: Select all
setsys SparingAlgorithm Minimal
admithw
setsys SparingAlgorithm Default
admithw
Will it help restore default spare chunks count?