Marc.mvh.vanhoof wrote:
Hi to all. Starting this year we compressed 2 x 8450 systems (all VV's) and ratio was 2/1! That was the good news. After a few days we run into the (read LD error issue) and decided to go back to not compressed. All convertion was done by tunevv and in that way it was not that much work. Performance during and after compression was ok. Now running 3.3.1 MU2 with the latest patches, we think we are ready to start with compression again.
Beeing experienced on dedup and compressen, I do have a question. We only have experience in converting not replicated VV's. It seems it is an other story when converting synchronous replicated VV's. One must give up replication during the convertion ! The only , most save, convertion procedure seems to be moving all data via VMotion (our environment is all VM's) from not compressed VV's to compressed VV's.
Question for you : Any idea to convert to compressed VV's in a synchronous replicated environment with minimal impact concerning replication , using tunevv. Any well working procedures available?
Beeing experienced on dedup and compressen, I do have a question. We only have experience in converting not replicated VV's. It seems it is an other story when converting synchronous replicated VV's. One must give up replication during the convertion ! The only , most save, convertion procedure seems to be moving all data via VMotion (our environment is all VM's) from not compressed VV's to compressed VV's.
Question for you : Any idea to convert to compressed VV's in a synchronous replicated environment with minimal impact concerning replication , using tunevv. Any well working procedures available?
I think any tune operations have always involved disabling sync rcopy on 3PAR for the volumes concerned, certainly anything at the VV level. Back when we had to move VVs from one CPG to another CPG after adding more disks to spread the data it was a requirement or recommendation at least (but we only had to stop the rcopy groups for the move), we at least can now use tunesys and do it at a lower level with rcopy running.
I'm new to the compression/dedupe features but for now in testing I'm taking the VV out of the rcopy group, compress the source, delete the target and re-add the VV to the rcopy group so it creates a new compressed target automatically.
In production (while we have the free space) I suspect I might prefer the VMotion option, after a backup.
