Re: Whatever Happened to the Data Mover Idea
On Jun 16, 2009, at 11:43 PM, Steven Harris wrote: One possibility would be to install TSM for SAN on the partitions that need it, but there is some administrative overhead with doing this, and we are finding that drive sharing is not as error free as we would like with only a 5 way split. We are seeing drives getting hung up with reserves, and are afraid that this will get much worse if more AIX lpars share them. Reserve problems make me wonder about storage agents that are not using persistent binding (If \dev\rmt3 goes from being the third drive in a frame to the second drive in a different frame, without the library manager knowing, what ensues is NOT hilarity) or that are especially poorly behaved (At one still-recent job, IBM analyzed enough drive data from hung-drives to help us identify a problem child, who promptly was put in the penalty box until he got a new HBA). As Remco says, it doesn't have to be that way. I'm now on my third shop with large numbers of servers and storage agents sharing one or more libraries.
Whatever Happened to the Data Mover Idea
Hi All A bit of explanation first... bear with it there is a point. One of my customers is implementing a big SAP landscape on AIX. The design has multiple P595s with many lpars. Backup was to be via hardware snapshot of volumes to San Volume Controller in front of DS8000 disk, which then get re-mounted and backed up using TDP for SAP. One lpar in each P595 is a TSM server and so data flows from client to server along a virtual backup network inside the P595, however this network is externalized and may be used to back up windows, MSSQL, exchange and other sundry bits and pieces that don't run on AIX. There is a new-ish facility of the Power boxes called Live Partition Mobility. If an lpar is properly set up so that all its resources are virtualized and external, it can be suspended, moved to a different physical machine and revived in a very short time - this facility is much like the thing VMWare can do for those of you not familiar with Power hardware. The next part of the implementation is set to use this facility. The issue is that should an lpar move to another physical machine, then the backup path will not flow internally along a very fast pipe but externally across the LAN. This will be unacceptably slow, as it must be possible to make a whole backup in 6 hours before the space is needed for the following snapshot. One possibility would be to install TSM for SAN on the partitions that need it, but there is some administrative overhead with doing this, and we are finding that drive sharing is not as error free as we would like with only a 5 way split. We are seeing drives getting hung up with reserves, and are afraid that this will get much worse if more AIX lpars share them. Once upon a time, it was mooted that disk controllers would be smart enough that Server free backups could be done, that is the disk controller talks direct to the tape drive across the SAN and the data does not need to pass through the client that originally requested the backup, I believe this was the original intent of the DATAMOVER options in the define path commands. I also dimly remember seeing a white paper about an array backing up direct to a SAN data gateway on an old 3583 library, I have been noodling about the IBM site and google and have not found anything. Can the SVC/DS8000 combination be used to backup my SAP volumes server free to a TS3500 library ? If so can anyone point me to appropriate documentation? Thanks for persisting this far , and thanks in advance for your assistance Steve Steven Harris TSM Admin Sydney Australia
Re: Whatever Happened to the Data Mover Idea
On 17 jun 2009, at 06:43, Steven Harris wrote: Hi All A bit of explanation first... bear with it there is a point. One of my customers is implementing a big SAP landscape on AIX. The design has multiple P595s with many lpars. Backup was to be via hardware snapshot of volumes to San Volume Controller in front of DS8000 disk, which then get re-mounted and backed up using TDP for SAP. One lpar in each P595 is a TSM server and so data flows from client to server along a virtual backup network inside the P595, however this network is externalized and may be used to back up windows, MSSQL, exchange and other sundry bits and pieces that don't run on AIX. There is a new-ish facility of the Power boxes called Live Partition Mobility. If an lpar is properly set up so that all its resources are virtualized and external, it can be suspended, moved to a different physical machine and revived in a very short time - this facility is much like the thing VMWare can do for those of you not familiar with Power hardware. The next part of the implementation is set to use this facility. The issue is that should an lpar move to another physical machine, then the backup path will not flow internally along a very fast pipe but externally across the LAN. This will be unacceptably slow, as it must be possible to make a whole backup in 6 hours before the space is needed for the following snapshot. One possibility would be to install TSM for SAN on the partitions that need it, but there is some administrative overhead with doing this, and we are finding that drive sharing is not as error free as we would like with only a 5 way split. We are seeing drives getting hung up with reserves, and are afraid that this will get much worse if more AIX lpars share them. This is not my experience, so things are not as they should be. I believe that the LAN-free agent is quite ok at this time, and the administrative overhead is quite limited. Once upon a time, it was mooted that disk controllers would be smart enough that Server free backups could be done, that is the disk controller talks direct to the tape drive across the SAN and the data does not need to pass through the client that originally requested the backup, I believe this was the original intent of the DATAMOVER options in the define path commands. I also dimly remember seeing a white paper about an array backing up direct to a SAN data gateway on an old 3583 library, I have been noodling about the IBM site and google and have not found anything. Can the SVC/DS8000 combination be used to backup my SAP volumes server free to a TS3500 library ? If so can anyone point me to appropriate documentation? server-free is a dead concept, it will never happen. Thanks for persisting this far , and thanks in advance for your assistance could you, on the lpar in charge of backing up you sap data, run a TSM server? Maybe make it a bit bigger and combine the two tasks? I run (as a test) a TSM server on an OCFS2 (clustered filesystem) node without any problems. You can then use sharedmem client/server communications, I'm sure things will fly ;-) Steve Steven Harris TSM Admin Sydney Australia -- Met vriendelijke groeten, Remco Post r.p...@plcs.nl +31 6 248 21 622
