Realistically, if Array B dies, you lose the Database "and" recovery log. The mirroring ain 't giving you protection from that. I would separate the recovery log to array A and lose the mirroring on both DB and log(maybe mirror log between arrays). Restoration of a broken DB should only mean a couple hours outage, in your case.
On Wed, 2002-10-23 at 01:03, Raghu S wrote: > Hi, > > There was a lot of discussion on this topic before.But i am requesting TSM > gurus give their comments again. > > The set up is like this. > > TSM Server : Windows NT 4.0 SP6, TSM 5.1.0.0 > > 392 MB memory, P III > > Adaptech Ultra SCSI > > Hard Disk : Internal Hardware RAID 5: > > array A : 8.678GB * 3 : 17.356GB data and 8.678 GB > parity > > array B : 35.003 GB * 3 : 70.006GB data and 35.003 > GB parity. > > > Both array A and array B are connected to the same channel. > > OS and TSM 5.1 are installed on array A > > TSM data base, recovery log and Disk storage pool are installed in array B. > > Database : 2GB+2GB = 4 GB and mirrored at TSM level on the same array > > Recovery Log : 500MB + 500 MB = 1 GB and mirrored at TSM level on the same > array > > Disk Storage pool : 10GB+10GB+10GB+10GB+5GB=45GB on array B > > > TSM client: 4.1.2.12 ( Tivoli says 4.1.2.12 is not supported with 5.1 > Server. But i could take the backup,archive and restore with this > combination ) > > Number of Clients : 55, all are windows > > Incremental backup : 1GB/ client/day. > > backup window : 9AM to 6PM with 50% randamization ( all are in polling mode > ) > > LAN : 100Mbps > > End of the day only 10 clients could finish the backup.Remaining all are > missing or "?" ( in progress ) or failed. > > Through the entire backup window the CPU load is 100% with dsmsvc.exe > holding 98% > > I tested with various options. I stopped the schedular and fired 3 clients > backup manually at the same time.Each client has 1 GB of incremental data. > It took three hours to finish the backup. While backing up i observed there > was lot of idletime outs of sessions. > > Network choke is not there. I checked this with FTP. > > Whats the bottleneck here? Is RAID 5 is creating problems ( DB,log and > storage pool all are on the RAID 5 )? I asked the customer to arrange a > testing machine without any RAID. I will be getting that in two days.Before > going on to the testing i like to know your comments on this. > > > > Regards > > Raghu S Nivas > Consultant - TSM > DCM Data Systems Ltd > New Delhi > India.
