Remote Copy Sync Failed

[RyanK]

Hey folks, hope everyone had a nice holiday period and new year.

We have a remote copy job where all but one of the volumes are syncing, and I don't know why this one volume is failing.

The detailed status seen in tasks section of the GUI for this particular volume is as so:

2024-01-03 10:26:36 GMT Created task.
2024-01-03 10:26:36 GMT Startup adding full sync of volume Vol1 in group 3PAR_2to1_Compute to target 3PAR1 to the synchronization list.
2024-01-03 10:26:36 GMT Started full sync of volume Vol1 (offset 0MB length 1048576MB) in group 3PAR_2to1_Compute to target 3PAR1 has started.(sync_vol: none/-2 resync_vol: none/-2.)
2024-01-03 11:13:55 GMT Read fail Synchronization failed to read from volume Vol1 and was stopped.
2024-01-03 11:13:56 GMT Failed sync of volume Vol1(Vol1) in Compute_RC group to target 3PAR1 failed, volume has status UNSYNC.

Other VVs within this group sync fine. There is nothing unusual about the VV that isn't syncing.

Any ideas or any ideas as to what is wrong/how to fix/how to find out a bit more about it please? I've done some searching for the errors on google, but not really found anything relevant.

Thanks a lot!

[MammaGutt]

Hey folks, hope everyone had a nice holiday period and new year.

We have a remote copy job where all but one of the volumes are syncing, and I don't know why this one volume is failing.

The detailed status seen in tasks section of the GUI for this particular volume is as so:

2024-01-03 10:26:36 GMT Created task.
2024-01-03 10:26:36 GMT Startup adding full sync of volume Vol1 in group 3PAR_2to1_Compute to target 3PAR1 to the synchronization list.
2024-01-03 10:26:36 GMT Started full sync of volume Vol1 (offset 0MB length 1048576MB) in group 3PAR_2to1_Compute to target 3PAR1 has started.(sync_vol: none/-2 resync_vol: none/-2.)
2024-01-03 11:13:55 GMT Read fail Synchronization failed to read from volume Vol1 and was stopped.
2024-01-03 11:13:56 GMT Failed sync of volume Vol1(Vol1) in Compute_RC group to target 3PAR1 failed, volume has status UNSYNC.

Other VVs within this group sync fine. There is nothing unusual about the VV that isn't syncing.

Any ideas or any ideas as to what is wrong/how to fix/how to find out a bit more about it please? I've done some searching for the errors on google, but not really found anything relevant.

Thanks a lot!

Hard to say with limited information.

Maybe my first try would be to recreate the RC group, just to start from scratch and there clearly isn't anything worth keeping on the target side.

From the little information provided it seems there is an issue with reading the source. It could be some old remote copy snapshot stuck (which would be cleared by re-creating the RC group) or it could be an issue with the source VV or it could be something completely else.


For looking deeper, you could do "showtask" in CLI to get the sync task id and run "showtask -d <id>" to get more detail.

[RyanK]

Hard to say with limited information.

Maybe my first try would be to recreate the RC group, just to start from scratch and there clearly isn't anything worth keeping on the target side.

From the little information provided it seems there is an issue with reading the source. It could be some old remote copy snapshot stuck (which would be cleared by re-creating the RC group) or it could be an issue with the source VV or it could be something completely else.


For looking deeper, you could do "showtask" in CLI to get the sync task id and run "showtask -d <id>" to get more detail.

Hi MammaGutt, thanks for the reply.

It's not that "there isn't worth anything keeping on the other side" - there definitely is, but it's all remote copy backups of production data, which we would need if one of the 3PAR units died. It would be just my luck to have a unit die right after I deleted the RCs off the other unit. There are 6 volumes in this group that all create their own sync tasks and this is the only one that fails, despite nothing being out of the ordinary on the one that fails.

Interestingly, showtask -d <taskID> simply returns exactly the same information I gave in my first post, which I took from the GUI. Showtask -d simply repeats that and doesn't seem to provide any new information, which is a shame as I was hoping to investigate it.

I may recreate the copy job at sometime in the future, but I'm just a contractor so would need ot run that by people who are on leave at the moment. All these volumes contain cluster storage for VM disks in our MS failover cluster, so I doubt it's a problem reading the data itself, as I would have expected the virtual machines using this volume to have issues if it were. But you are right the error does seem to be a problem reading the source so it could well be something with a stuck snapshot, I didn't even realise that was a thing!

[MammaGutt]

Hard to say with limited information.

Maybe my first try would be to recreate the RC group, just to start from scratch and there clearly isn't anything worth keeping on the target side.

From the little information provided it seems there is an issue with reading the source. It could be some old remote copy snapshot stuck (which would be cleared by re-creating the RC group) or it could be an issue with the source VV or it could be something completely else.


For looking deeper, you could do "showtask" in CLI to get the sync task id and run "showtask -d <id>" to get more detail.

Hi MammaGutt, thanks for the reply.

It's not that "there isn't worth anything keeping on the other side" - there definitely is, but it's all remote copy backups of production data, which we would need if one of the 3PAR units died.

I'm not saying to re-create everything remote copy, I'm saying to re-create this one group or create a new group for volume Vol1. RC is saying it will do a full sync for this volume, which means that whatever you have of Vol1 on the target side is garbage and not worth a penny and remote copy will overwrite the entire volume with a full sync.