[gpfsug-discuss] mmapplypolicy didn't migrate everything it should have - why not?

Buterbaugh, Kevin L Kevin.Buterbaugh at Vanderbilt.Edu
Sun Apr 16 14:47:20 BST 2017


Hi All,

First off, I can open a PMR for this if I need to.  Second, I am far from an mmapplypolicy guru.  With that out of the way … I have an mmapplypolicy job that didn’t migrate anywhere close to what it could / should have.  From the log file I have it create, here is the part where it shows the policies I told it to invoke:

[I] Qos 'maintenance' configured as inf
[I] GPFS Current Data Pool Utilization in KB and %
Pool_Name                   KB_Occupied        KB_Total  Percent_Occupied
gpfs23capacity              55365193728    124983549952     44.297984614%
gpfs23data                 166747037696    343753326592     48.507759721%
system                                0               0      0.000000000% (no user data)
[I] 75142046 of 209715200 inodes used: 35.830520%.
[I] Loaded policy rules from /root/gpfs/gpfs23_migration.policy.
Evaluating policy rules with CURRENT_TIMESTAMP = 2017-04-15 at 01:13:02 UTC
Parsed 2 policy rules.

RULE 'OldStuff'
  MIGRATE FROM POOL 'gpfs23data'
  TO POOL 'gpfs23capacity'
  LIMIT(98)
  WHERE (((DAYS(CURRENT_TIMESTAMP) - DAYS(ACCESS_TIME)) > 14) AND (KB_ALLOCATED > 3584))

RULE 'INeedThatAfterAll'
  MIGRATE FROM POOL 'gpfs23capacity'
  TO POOL 'gpfs23data'
  LIMIT(75)
  WHERE ((DAYS(CURRENT_TIMESTAMP) - DAYS(ACCESS_TIME)) < 14)

And then the log shows it scanning all the directories and then says, "OK, here’s what I’m going to do":

[I] Summary of Rule Applicability and File Choices:
 Rule#      Hit_Cnt          KB_Hit          Chosen       KB_Chosen          KB_Ill     Rule
     0      5255960     237675081344        1868858     67355430720               0     RULE 'OldStuff' MIGRATE FROM POOL 'gpfs23data' TO POOL 'gpfs23capacity' LIMIT(98.000000) WHERE(.)
     1          611       236745504             611       236745504               0     RULE 'INeedThatAfterAll' MIGRATE FROM POOL 'gpfs23capacity' TO POOL 'gpfs23data' LIMIT(75.000000) WHERE(.)

[I] Filesystem objects with no applicable rules: 414911602.

[I] GPFS Policy Decisions and File Choice Totals:
 Chose to migrate 67592176224KB: 1869469 of 5256571 candidates;
Predicted Data Pool Utilization in KB and %:
Pool_Name                   KB_Occupied        KB_Total  Percent_Occupied
gpfs23capacity             122483878944    124983549952     97.999999993%
gpfs23data                 104742360032    343753326592     30.470209865%
system                                0               0      0.000000000% (no user data)

Notice that it says it’s only going to migrate less than 2 million of the 5.25 million candidate files!!  And sure enough, that’s all it did:

[I] A total of 1869469 files have been migrated, deleted or processed by an EXTERNAL EXEC/script;
        0 'skipped' files and/or errors.

And, not surprisingly, the gpfs23capacity pool on gpfs23 is nowhere near 98% full:

Disks in storage pool: gpfs23capacity (Maximum disk size allowed is 519 TB)
eon35Ansd               58.2T       35 No       Yes          29.54T ( 51%)        63.93G ( 0%)
eon35Dnsd               58.2T       35 No       Yes          29.54T ( 51%)        64.39G ( 0%)
                -------------                         -------------------- -------------------
(pool total)           116.4T                                59.08T ( 51%)        128.3G ( 0%)

I don’t understand why it only migrated a small subset of what it could / should have?

We are doing a migration from one filesystem (gpfs21) to gpfs23 and I really need to stuff my gpfs23capacity pool as full of data as I can to keep the migration going.  Any ideas anyone?  Thanks in advance…

—
Kevin Buterbaugh - Senior System Administrator
Vanderbilt University - Advanced Computing Center for Research and Education
Kevin.Buterbaugh at vanderbilt.edu<mailto:Kevin.Buterbaugh at vanderbilt.edu> - (615)875-9633



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