Mirroring: hard or soft ?

Hi all, I have to upgrade one of my customer database from SE (HPUX + SE 4.10 on HP 9000 8x7) to Online Workgroup Server (7.2*) or IDS 7.30 on a HP Netserver (bi-Pentium Xeon) with 2 hard drives of 9GB each. The database is about 1.5Gb in SE. I wonder if the best way is to mirror one disk over the second or to let IOWS manage his own mirroring at a software level (using raw devices of course). Perhaps will it be useful to mirror ROOTDBS and LOGDBS for security reasons but not the data DBS ? I'm not sure it will make a big difference in terms of performance but what about security in case of a crash ??? Please help ...

Are you concerned about performance ?? If you are, then you should seriously consider getting more 4GB drives rather than 9GB drives. Does the application use logging ? If so, consider getting another disk for the logs. You will definitely need to mirror the rootdbs and phylogdbs. Depending on security, also mirror the data dbspace. You shouldn't necessarily need to mirror the loglogdbs ( as you only have 2 disks ) as long as you are continuously archiving the logs, as and when they fill. If you can possibly get some more disk out of management, do it. You will definitely need more than 2 disks for the system to perform even to an acceptable level. I hope you don't expect to see vast improvements in performance over SE. You may be very disappointed...( particularly when OS stuff and all the other applications ) Set management expectation levels as low as you possibly can ( no, its not an Informix parameter ) - don't be too enthusiastic about how 'fast' the new server is going to be until you've seen it in operation doing its usual day to day stuff. Its not all doom and gloom - I would class it as a valuable learning experience. Sean Laurent COLLIGNON wrote in message <36D56C87.415AFF79@imsii.fr>... >Hi all, > >I have to upgrade one of my customer database from SE (HPUX + SE 4.10 on >HP 9000 8x7) to Online Workgroup Server (7.2*) or IDS 7.30 on a HP >Netserver (bi-Pentium Xeon) with 2 hard drives of 9GB each. >The database is about 1.5Gb in SE. > >I wonder if the best way is to mirror one disk over the second or to let >IOWS manage his own mirroring at a software level (using raw devices of >course). > >Perhaps will it be useful to mirror ROOTDBS and LOGDBS for security >reasons but not the data DBS ? I'm not sure it will make a big >difference in terms of performance but what about security in case of a >crash ??? > >Please help ... >

With only two disks, performance may be hit if all dataspaces are held on one and mirrored to another, even though mirroring will aid slightly with read performance. That said, mirroring will provide you with the means to keep running in the event of a disk crash. If you are using both disks to segment dataspaces then a disk crash will lose you the system - as well as alot of time and potentially data. Where is the performance gain when the system is down??? Jeff McFee Lysander Systems Limited In article <36D56C87.415AFF79@imsii.fr>, Laurent COLLIGNON <lcollignon@imsii.fr> wrote: > Hi all, > > I have to upgrade one of my customer database from SE (HPUX + SE 4.10 on > HP 9000 8x7) to Online Workgroup Server (7.2*) or IDS 7.30 on a HP > Netserver (bi-Pentium Xeon) with 2 hard drives of 9GB each. > The database is about 1.5Gb in SE. > > I wonder if the best way is to mirror one disk over the second or to let > IOWS manage his own mirroring at a software level (using raw devices of > course). > > Perhaps will it be useful to mirror ROOTDBS and LOGDBS for security > reasons but not the data DBS ? I'm not sure it will make a big > difference in terms of performance but what about security in case of a > crash ??? > > Please help ... > > -----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own