reducevg very slow

This is an APAR, but really it’s a description. Reducevg sends the equivalent of TRIM commands, but on a storage array, this is writing nulls. On a big LUN, or with a busy array, this can take a long time. If you do not need to worry about this, then you can disable that space reclaim.

ioo -o -dk_lbp_enabled=0

Here is the IBM doc about it.

 

IJ23045: REDUCEVG UNCLEAR ON DELAY WHEN WAITING FOR INFLIGHT RECLAIM REQ APPLIES TO AIX 7100-05

 

A fix is available

APAR status

  • Closed as program error.

Error description

  • reducevg may be unclear, why there is some delay
    when waiting on inflight reclaim requests.
    

Local fix

  • Disable space reclamation by running:
    ioo -o dk_lbp_enabled=0
    

Problem summary

  • reducevg may be unclear, why there is some delay
    when waiting on inflight reclaim requests.
    

Problem conclusion

  • reducevg displays message incase there are space reclamation
    IOs inflight to indicate reducevg may take some time to
    complete.

SVC, StorWize, FlashSystem, Spectrum Virtualize – replace a drive

I always forget, so here’s a reminder…

When you replace a drive on one of these, mdisk arrays do not auto-rebuild.

If the GUI fix procedures go away, or never show up, or whatever causes the replacement drive to not get included as a new drive in the mdisk, you can do this manually.

First, look for the candidate or spare drive you want to use.
lsmdisk

Then, make sure that drive ID is a candidate:
chdrive -use candidate 72

Then, find the missing member:
lsarraymember mdisk1

Then, set the new drive to use that missing member ID:
charraymember -member 31 -newdrive 72 mdisk1

You can watch the progress of the rebuild:
lsarraymemberprogress mdisk1