Mcaubet: Created page with "== Migrate the pool leaving the source with cached copies of the files== In a dCache pool use "help migration" and "help migration copy" to know more about the migration modu..."

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Created page with "== Migrate the pool leaving the source with cached copies of the files== In a dCache pool use "help migration" and "help migration copy" to know more about the migration modu..."

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== Migrate the pool leaving the source with cached copies of the files==

In a dCache pool use "help migration" and "help migration copy" to know more about the migration module. The syntax might be different now, the following was tested with 1.9.5-23:

'''migration copy -sticky -concurrency=6 -pins=move -smode=removable -tmode=same -target=pgroup pgroup-atlas-ddn'''

Where pgroup-atlas-ddn should be a different pgroup (Pool Group) from the source pool's pgroup if not using a version higher than 1.9.10.
Concurrency should be adapted to the source server capacity and the number/capacity of the destination pgroup.

== Migrate the pool leaving the source empty==

* Ensure that source and destination dCache pools are UP and running dCache-server 1.9.1-7 or higher version.
* Set source pool to rdonly. This is: go to PoolManager and run "psu set pool $poolName rdonly"
* Optionally you can create a ZFS snapshot on source pool
<pre>
root@dc023 # zfs list
NAME USED AVAIL REFER MOUNTPOINT
dcpool 9.60T 6.85T 9.60T /dcpool
root@dc023 # zfs snapshot dcpool@0904161212
root@dc023 # zfs list
NAME USED AVAIL REFER MOUNTPOINT
dcpool 9.60T 6.85T 9.60T /dcpool
dcpool@0904161212 0 - 9.60T -
root@dc023 #
</pre>
* Login to pCells and go to source pool
** Ensure that there's no migration process running; "migration ls" should return nothing
** Start the migration process with "migration move [options] <target> ...". By default no options are needed. You should see something like:
<pre>
[1] INITIALIZING migration move dc060_1
<< --- Thu Apr 16 11:21:24 GMT+01:00 2009 --- >>
</pre>

** Verify that the migration process is running with "migration ls" and "migration info":
<pre>
[1] RUNNING migration move dc060_1

<< --- Thu Apr 16 11:24:48 GMT+01:00 2009 --- >>

Command : migration move dc060_1
State : RUNNING
Queued : 136456
Attempts : 124
Targets : dc060_1
Completed : 123 files; 8695281287 bytes; 0%
Total : 10546631499269 bytes
Concurrency: 1
Running tasks:
[123] 00030000000000000B681108: TASK.GettingLocations

<< --- Thu Apr 16 11:24:50 GMT+01:00 2009 --- >>

Command : migration move dc060_1
State : RUNNING
Queued : 136453
Attempts : 127
Targets : dc060_1
Completed : 126 files; 8843944729 bytes; 0%
Total : 10546631499269 bytes
Concurrency: 1
Running tasks:
[126] 00030000000000000BE93148: TASK.Copying -> [>dc060_1@local]

<< --- Thu Apr 16 11:25:00 GMT+01:00 2009 --- >>
</pre>

To monitor the migration process in the pools you can use "zpool iostat 10" in both the source and destination pools:
<pre>
root@dc060 # zpool iostat 10
capacity operations bandwidth
pool used avail read write read write
---------- ----- ----- ----- ----- ----- -----
dcpool 14.4G 40.8T 0 4 6 178K
dcpool 15.0G 40.8T 0 431 0 50.0M
dcpool 15.6G 40.8T 0 395 0 45.3M
dcpool 15.9G 40.8T 0 296 0 31.7M
dcpool 16.5G 40.8T 0 442 0 51.3M
dcpool 17.0G 40.8T 0 338 0 38.4M

root@dc023 # zpool iostat 10
capacity operations bandwidth
pool used avail read write read write
---------- ----- ----- ----- ----- ----- -----
dcpool 11.8T 8.63T 43 34 5.12M 2.20M
dcpool 11.8T 8.63T 300 49 36.8M 224K
dcpool 11.8T 8.63T 314 47 38.5M 215K
dcpool 11.8T 8.63T 354 48 43.4M 220K
</pre>

HowTo: Migrate dCache Pool - Revision history

Mcaubet: Created page with "== Migrate the pool leaving the source with cached copies of the files== In a dCache pool use "help migration" and "help migration copy" to know more about the migration modu..."