[gpfsug-discuss] Is there a difference in suspend and empty NSD state?

[IBM Spectrum Scale]

Option 'suspend' is same to 'empty' if  the cluster is updated to Scale
4.1.1. The option 'empty' was introduced in 4.1.1 to support disk deletion
in a fast way, 'suspend' option was not removed with due consideration for
previous users.

> And really what I currently want to do is suspend a set of disks,
> and then mark a different set of disks as “to be emptied”.  Then I
> will run a mmrestripefs operation to move the data off of the “to be
> emptied” disks, but not onto the suspended disks (which will also be
> removed from the file system in the near future).  Once the NSDs are
> emptied then it will be a very (relatively) fast mmdeldisk
> operation.  So is that possible?

It's possible only if these two sets of disks belong to two different pools
.

If they are in the same pool,  restripefs on the pool will migrate all data
off these two sets of disks.

If they are in two different pools, you can use mmrestripefs with -P option
to migrate data off "suspended" and "to be emptied" disks in the specified
data pool. Please note that system pool is special, mmrestripefs will
unconditionally restripe the system pool even you specified -P option to a
data pool.


Regards, The Spectrum Scale (GPFS) team

------------------------------------------------------------------------------------------------------------------

If you feel that your question can benefit other users of  Spectrum Scale
(GPFS), then please post it to the public IBM developerWroks Forum at
https://www.ibm.com/developerworks/community/forums/html/forum?id=11111111-0000-0000-0000-000000000479.


If your query concerns a potential software error in Spectrum Scale (GPFS)
and you have an IBM software maintenance contract please contact
1-800-237-5511 in the United States or your local IBM Service Center in
other countries.

The forum is informally monitored as time permits and should not be used
for priority messages to the Spectrum Scale (GPFS) team.

gpfsug-discuss-bounces at spectrumscale.org wrote on 2020/04/23 06:34:33:

> From: Bryan Banister <bbanister at jumptrading.com>
> To: gpfsug main discussion list <gpfsug-discuss at spectrumscale.org>
> Date: 2020/04/23 06:35
> Subject: [EXTERNAL] [gpfsug-discuss] Is there a difference in
> suspend and empty NSD state?
> Sent by: gpfsug-discuss-bounces at spectrumscale.org
>
> Hello all,
>
> Looking at the man page, it is fairly ambiguous as to these NSD
> states actually being different (and if not WHY have to names for
> the same thing?!):
>
> suspend
> or
> empty
>          Instructs GPFS to stop allocating space on the specified
>          disk. Put a disk in this state when you are preparing to
>          remove the file system data from the disk or if you want
>          to prevent new data from being put on the disk. This is
>          a user-initiated state that GPFS never enters without an
>          explicit command to change the disk state. Existing data
>          on a suspended disk may still be read or updated.
>
>          A disk remains in a suspended or to be
>          emptied state until it is explicitly resumed.
>          Restarting GPFS or rebooting nodes does not restore
>          normal access to a suspended disk.
>
> And from the examples lower in the page:
>    Note: In product versions earlier than V4.1.1, the
>    mmlsdisk command lists the disk status as
>    suspended. In product versions V4.1.1 and later, the
>    mmlsdisk command lists the disk status as to be
>    emptied with both mmchdisk suspend or mmchdisk
>    empty commands.
>
>
> And really what I currently want to do is suspend a set of disks,
> and then mark a different set of disks as “to be emptied”.  Then I
> will run a mmrestripefs operation to move the data off of the “to be
> emptied” disks, but not onto the suspended disks (which will also be
> removed from the file system in the near future).  Once the NSDs are
> emptied then it will be a very (relatively) fast mmdeldisk
> operation.  So is that possible?
>
> As you can likely tell, I don’t have enough space to just delete
> both sets of disks at once during a (yay!) full file system
> migration to the new GPFS 5.x version.
>
> Thought this might be useful to others, so posted here.  Thanks in
> advance neighbors!
> -Bryan_______________________________________________
> gpfsug-discuss mailing list
> gpfsug-discuss at spectrumscale.org
> https://urldefense.proofpoint.com/v2/url?
>
u=http-3A__gpfsug.org_mailman_listinfo_gpfsug-2Ddiscuss&d=DwICAg&c=jf_iaSHvJObTbx-

>
siA1ZOg&r=IbxtjdkPAM2Sbon4Lbbi4w&m=QxEYrybXOI6xpUEVxZumWQYDMDbDLx4O4vrm0PNotMw&s=4M2-

> uNMOrvL7kEQu_UmL5VvnkKfPL-EpSapVGkSX1jc&e=
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://gpfsug.org/pipermail/gpfsug-discuss_gpfsug.org/attachments/20200423/80fd84c6/attachment-0002.htm>