VNX for file - nfs - snapshots

Hi, VNX for file, nfs share mounted on a vdm.

Automatic snapshots scheduled at .00 every hour.

From VNX I can see snapshots as expected:

vnx-snapshot.JPG.jpg

but from a linux client mounting that file system I can see some snapshot which are not on VNX (!!) - highlighted in bold.

cheesep@XXX:~/.ckpt$ ls -alt

total 257

dr-xr-xr-x 2 root    root   512 May 26 17:16 .

drwx-----x 3 cheesep staff 1024 May 22 14:17 2015_05_26_09.00.03_Europe_London

drwx-----x 3 cheesep staff 1024 May 22 14:17 2015_05_26_10.00.00_Europe_London

drwx-----x 3 cheesep staff 1024 May 22 14:17 2015_05_26_11.00.02_Europe_London

drwx-----x 3 cheesep staff 1024 May 22 14:17 2015_05_26_12.00.01_Europe_London

drwx-----x 3 cheesep staff 1024 May 22 14:17 2015_05_26_13.00.03_Europe_London

drwx-----x 3 cheesep staff 1024 May 22 14:17 2015_05_26_14.00.04_Europe_London

drwx-----x 3 cheesep staff 1024 May 22 14:17 2015_05_26_15.00.01_Europe_London

drwx-----x 3 cheesep staff 1024 May 22 14:17 2015_05_26_16.00.03_Europe_London

drwx-----x 3 cheesep staff 1024 May 22 14:17 2015_05_26_17.00.03_Europe_London

drwx-----x 3 cheesep staff 1024 May 22 14:17 2015_05_26_17.11.23_Europe_London

drwx-----x 3 cheesep staff 1024 May 22 14:17 2015_05_26_17.15.23_Europe_London

These last two "strange" snapshots can vary from a specific time to the next run of a snapshot job.

Any idea what can I check on the client side? Linux Ubuntu and Solaris clients behave the same.

EMC support already involved and nothing found on the VNX side.

Thanks.

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8 Replies
dynamox
6 Gallium

Re: VNX for file - nfs - snapshots

is that file system replicated ?

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Highlighted

Re: VNX for file - nfs - snapshots

Yes it is. It replicates with another VNX at a secondary site every 1 minute.

If they are snapshots created by the replicaiton job, I'd expect their timestamp to change every 1 minutes or so, but it does not.

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dynamox
6 Gallium

Re: VNX for file - nfs - snapshots

same replication schedule configured for vdm ?

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Peter_EMC
3 Silver

Re: VNX for file - nfs - snapshots

matteo_marchetti wrote:

If they are snapshots created by the replicaiton job, I'd expect their timestamp to change every 1 minutes or so, but it does not.

The timestamps would only change every minute, if there is data to be copied to the destination and if the amount of data to be copied to the destination could be finished in one minute.

You can check the checkpoints doing a

fs_ckpt fsname -l -a on the controlstation. Typically the first 2 with the name beginning with "root_rep_ckpt" belong to the replication session.

Verify this output with the output of the linux client (ls -alt)

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cadencep45
2 Iron

Re: VNX for file - nfs - snapshots

if they are replication snapshots, from the control station, running

nas_replicate -list

should list the replication sessions and then running

nas_replicate -info <session_name> , where session name is provided from the output of the first command tells you if the replication session is up to date and the rate of data transfer between primary and secondary sites.

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Re: VNX for file - nfs - snapshots

Hi Peter, I don't fully understand the "connection" between these two:

[nasadmin@C-VNX1-CS ~]$ fs_ckpt c-nfs-staff -l -a

id    ckpt_name                creation_time           inuse fullmark   total_savvol_used  ckpt_usage_on_savvol

754   root_rep_ckpt_301_700035 01/07/2015-16:52:00-GMT   y   90%        20%                1%

755   root_rep_ckpt_301_700035 01/07/2015-16:52:03-GMT   y   90%        20%                1%

and

cheesep@XXX:~/.ckpt$ ls -alt

drwx-----x 3 cheesep staff 1024 May 22 14:17 2015_05_27_09.00.04_Europe_London

drwx-----x 3 cheesep staff 1024 May 22 14:17 2015_05_27_10.00.00_Europe_London

drwx-----x 3 cheesep staff 1024 May 22 14:17 2015_05_27_10.00.33_Europe_London

drwx-----x 3 cheesep staff 1024 May 22 14:17 2015_05_27_10.11.53_Europe_London

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Peter_EMC
3 Silver

Re: VNX for file - nfs - snapshots

the fs_ckpt fsname -l -a is listing you all existing checkpoints of a FS.

The ip-replication is based on  two checkpoints, they are refreshed round robin.

fs_ckpt is listing the creation time of the checkpoints, while the ls -l is giving the name based on the last uptime.

With a running ip-replication. fs_ckpt fsname -l -a will list the 2 replication checkpoints and your custom created ones.

To determine, which of the 2 replication checkpoints is which mountpoint is a bit tricky. But as they should not be used by anything else than the ip-replication itself, it shouldn´t matter which one is which one.

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Re: VNX for file - nfs - snapshots

Thanks Peter it makes sense.

I've forced some new data to be copied to the secondary site and I've checked that the two additional snapshots are "rotating" as you said.

drwx-----x 3 cheesep staff 1024 May 27 14:42 2015_05_27_14.43.13_Europe_London

drwx-----x 3 cheesep staff 1024 May 27 14:42 2015_05_27_14.42.33_Europe_London



drwx-----x 3 cheesep staff 1024 May 27 14:45 2015_05_27_14.45.53_Europe_London

drwx-----x 3 cheesep staff 1024 May 27 14:42 2015_05_27_14.43.13_Europe_London



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