----- Original Message ----- From: "Daniel Sparrman" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Monday, August 01, 2005 9:31 AM Subject: Re: [ADSM-L] mirrorwritedb parallel - tried it?
*cut* The security risk is mainly in a scenario were TSM writes to both of the db volumes and crashes at the same time. This could result in a partial write = database restore. To avoid this security issue when using parallel writes, enable pageshadowing with "dbpageshadow yes" and "dbpageshadowfile FILENAME". The pageshadowfile should preferable be placed on separate disks from the TSM database volumes. *cut* If you use parallel writes and dbpageshadow, aren't you do sequential writing again? As far as i know, dbpageshadow is used with hardware-mirror in stead of TSM-mirror, so there is still a sequential write possible. So if you use parallel writes for a better performance and use dbpageshadow, you still use sequential writes between the real db and the shadow and lose the performance bennefit. Regards, Maurice
