MSA 2040 Can't create new disk group

[Patric Falinder]

Hello,

I have a MSA 2040 SAN with dual controllers. I just put in 4 new drives and wanted to install them.

I tried to create a new Disk Group as RAID-5 but I get the following message:

Here is some additional information from my SAN:

HP MSA Storage MSA 2040 SAN
System Name: MSA 2040
System Location: removed
Version: GL225P002-02

# show disks
Location   Serial Number         Vendor   Rev   Description Usage         Jobs Speed (kr/min)  Size     Sec Fmt    Disk Group Pool Tier       Health
---------------------------------------------------------------------------------------------------------------------------------------------------------
1.1        HP       HPD4  SAS         VIRTUAL POOL       10              900.1GB  512n       dgA01      A    Standard   OK
1.2        HP       HPD4  SAS         VIRTUAL POOL       10              900.1GB  512n       dgA01      A    Standard   OK
1.3          HP       HPD4  SAS         VIRTUAL POOL       10              900.1GB  512n       dgA01      A    Standard   OK
1.4        HP       HPD4  SAS         VIRTUAL POOL       10              900.1GB  512n       dgA01      A    Standard   OK
1.5        HP       HPD4  SAS         VIRTUAL POOL       10              900.1GB  512n       dgA01      A    Standard   OK
1.6        HP       HPD4  SAS         VIRTUAL POOL       10              900.1GB  512n       dgA01      A    Standard   OK
1.7        HP       HPD4  SAS         VIRTUAL POOL       10              900.1GB  512n       dgB01      B    Standard   OK
1.8        HP       HPD4  SAS         VIRTUAL POOL       10              900.1GB  512n       dgB01      B    Standard   OK
1.9        HP       HPD4  SAS         VIRTUAL POOL       10              900.1GB  512n       dgB01      B    Standard   OK
1.10       HP       HPD4  SAS         VIRTUAL POOL       10              900.1GB  512n       dgB01      B    Standard   OK
1.11       HP       HPD4  SAS         VIRTUAL POOL       10              900.1GB  512n       dgB01      B    Standard   OK
1.12       HP       HPD4  SAS         VIRTUAL POOL       10              900.1GB  512n       dgB01      B    Standard   OK
1.13       SEAGATE  C006  SSD SAS     VIRTUAL POOL       0               400.0GB  512e       rcA1       A    Read Cache OK
1.14       SEAGATE  C006  SSD SAS     VIRTUAL POOL       0               400.0GB  512e       rcB1       B    Read Cache OK
1.15       HP       HPD5  SAS         AVAIL              10              1800.3GB 512e                       N/A        OK
1.16       HP       HPD5  SAS         AVAIL              10              1800.3GB 512e                       N/A        OK
1.17       HP       HPD5  SAS         AVAIL              10              1800.3GB 512e                       N/A        OK
1.18       HP       HPD5  SAS         AVAIL              10              1800.3GB 512e                       N/A        OK
---------------------------------------------------------------------------------------------------------------------------------------------------------
Info:  * Rates may vary. This is normal behavior. (2020-08-12 13:23:31)

Success: Command completed successfully. (2020-08-12 13:23:31)

# show pools
Name Serial Number                    Class    Total Size Avail    Snap Size OverCommit  Disk Groups Volumes  Low Thresh  Mid Thresh  High Thresh  Sec Fmt   Health     Reason Action
--------------------------------------------------------------------------------------------------------------------------------------------------------------------
A    00c0ff287d6a000073061b5901000000 Virtual  4494.1GB   2111.6GB 0B        Enabled     2           3        25.00 %     50.00 %     95.22 %      Mixed     OK
B    00c0ff28759b0000a8061b5901000000 Virtual  4494.1GB   1911.4GB 0B        Enabled     2           2        25.00 %     50.00 %     95.22 %      Mixed     OK
--------------------------------------------------------------------------------------------------------------------------------------------------------------------
Success: Command completed successfully. (2020-08-12 13:23:44)

# show disk-groups
Name   Size     Free     Class    Pool Tier       % of Pool  Own Pref   RAID   Disks Spr Chk  Status Jobs      Job%      Serial Number                    Spin Down              SD Delay              Sec Fmt   Health     Reason Action
--------------------------------------------------------------------------------------------------------------------------------------------------------------------
dgA01  4494.1GB 2111.6GB Virtual  A    Standard   100        A   A      RAID5  6     0   64k  FTOL                       00c0ff287d6a000072061b5900000000 Disabled               0                     512n      OK
rcA1   397.5GB  33.7GB   Virtual  A    Read Cache 0          A   A      NRAID  1     0   N/A  UP                         00c0ff287d6a000086061b5900000000 Disabled               0                     512e      OK
dgB01  4494.1GB 1911.4GB Virtual  B    Standard   100        B   B      RAID5  6     0   64k  FTOL                       00c0ff28759b0000a5061b5900000000 Disabled               0                     512n      OK
rcB1   397.5GB  136.7GB  Virtual  B    Read Cache 0          B   B      NRAID  1     0   N/A  UP                         00c0ff28759b0000b7061b5900000000 Disabled               0                     512e      OK
--------------------------------------------------------------------------------------------------------------------------------------------------------------------

I have two SSD Read Cahce, one for each controller as you can see in the configuration.

Do I need to buy some license just to install more drives to my SAN? Or am I doing something wrong here?

[arun_r · Accepted solution]

Hi Patric,

Please delete the read cache disk groups to resolve the issue.

Note: Schedule the activity during low IOs as there would be read performance degradation after deleting read cache disk group.

You may recreate the read cache disk group once the new SAS disk group has been created.

[SUBHAJIT KHANBARMAN_1]

@Patric Falinder 

There are certain check marks which you need to fulfill,

>> We can see that you have SSD read cache configured so you can't create normal SSD Vitual Disk Group (VDG) with the presense of SSD read cache. At a time either SSD read cache or SSD VDG can exists, both can't exist together in same Pool. So delete SSD read cache as Arun mentioned otherwise you can plan SSD performance tier VDG in Pool B as well.

>> Next thing you require "Advanced Data Services Suite" license because you are using two different type of drives. Here you are trying to create new SSD VDG with 4 new SSD drives with the presense of other normal SAS drives in the system. So this new SSD VDG will be considered as Performance tier which can't be possible without proper license installed. Check if this license installed or not.

Hope this helps!
Regards
Subhajit

I am an HPE employee

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*************************************************************************

[Patric Falinder]

Thank you very much! This worked.

I removed both read caches and then I could create the new disk group. After that I created the read caches again without a problem.

I have just one more question. The dgB01 disk-group is showing "46% VRSC" now for some reason. What does this mean?

I googled and found something about scrubing, which sounds kind of like it's eraising the entire disk group.. But maybe it's some automatic "health check" thing?

[arun_r]

Hi,

I'm glad I could help

From SMU guide:

https://support.hpe.com/hpesc/public/docDisplay?docId=c04220794

The system-level Vdisk Scrub option automatically checks all vdisks for disk defects. Scrub analyzes a vdisk to find and fix disk errors. It will fix parity mismatches for RAID 3, 5, 6, and 50; mirror mismatches for RAID 1 and 10; and media errors for all RAID levels

Disk group scrub does not delete any data and its just a back ground  health check activity to check and fix errors.

You may end the scrub and restart it, if its still stuck at the same percentage for several hours.

[Patric Falinder]

Thank you so much for the help!

I can now continue the the data migration in peace.