Using Topio with IDS

All I am in the process of commissioning a new server (AIX 5.3 running IDS 9.4 on raw disk and Tools 7.32). A part of this process is to investigate Business Continuity solutions. I have been offered the standard of 'restore your backup to our kit at your site or our site' and, being tried and trusted, this is at the fore-front of our thoughts. However I have also been offered a solution that intercepts disk writes at a block level which are then transferred to another machine and applied to a duplicate disk. Note this is NOT HDR. The underlying software mechanism comes from a company called Topio. I have not heard of the company and am uncertain whether this is viable mechanism for ensuring a consistant system/database is available in the event of a disaster. I have been assured that Topio has 'many customers in the States' who use their product on AIX and IDS. Is anyone in a position to confirm this (off-line if preferred) and what have your experiances been? Keith ********************************************************************************** This message is sent in strict confidence for the addressee only. It may contain legally privileged information. The contents are not to be disclosed to anyone other than the addressee. Unauthorised recipients are requested to preserve this confidentiality and to advise the sender immediately of any error in transmission. This footnote also confirms that this email message has been swept for the presence of computer viruses, however we cannot guarantee that this message is free from such problems. ********************************************************************************** sending to informix-list

Simmons, Keith wrote: > All > > I am in the process of commissioning a new server (AIX 5.3 > running IDS 9.4 on raw disk and Tools 7.32). A part of this > process is to investigate Business Continuity solutions. I > have been offered the standard of 'restore your backup to > our kit at your site or our site' and, being tried and > trusted, this is at the fore-front of our thoughts. However > I have also been offered a solution that intercepts disk > writes at a block level which are then transferred to > another machine and applied to a duplicate disk. Note this > is NOT HDR. Indeed it is not > The underlying software mechanism comes from a company > called Topio. I have not heard of the company and am > uncertain whether this is viable mechanism for ensuring a > consistant system/database is available in the event of a > disaster. I have been assured that Topio has 'many customers > in the States' who use their product on AIX and IDS. > Is anyone in a position to confirm this (off-line if > preferred) and what have your experiances been? I have not used/seen topio However I HAVE tested drbd, ( www.drbd.org) which SEEMS to be similar (i.e raid1 at the network level) with IDS and it is fine. I used it in conjunction with linux HA and failover occurs fine, without as far as I can tell, data loss. -- Clive

By itself it is not since Informix requires disk writes to different chunks to occur in a certain order. E.g. physical log pages must be written before data pages. When the software says the write has made it to the disk it may not actually be on the physical media. However this would work combined with onbar external backup and restore. 1. Copy blocks to a mirrored drive on remote machine. 2. Do onbar external backup onmode -c block (checkpoints,writes everything to disk andpauses IDS) onbar -b -e ...whatever (external backup)3. Break mirror 4. onmode -c unblock (IDS continues a write to one side of mirror) 5. Backup other side of mirror to tape or sync to another drive 6. Resync mirror. One nice thing with EMC was whilst the mirror was broken the EMC unit tracked which disk tracks have been written to. Step 6 (resync mirror) would just copy out of date tracks to resync the mirror!).