En consecuencia de la reestructuracin de las BBDD de Exchange, para abarcar ms usuarios y para mejorar el rendimiento, se propone redimensionar la SAN que actualmente tenemos y particionarla en varias LUNS. La propuesta que realizamos, siguiendo las recomendaciones del documento Optimizing Storage for Exchange 2003_ES_V1 de Microsoft, es que las BBDD estn en un disco en RAID 0 + 1, pero nuestros expertos en storage nos recomiendan que las pongamos en un RAID5, ya que comentan que la tecnologa ha avanzado y que actualmente el RAID 0 + 1 no se utiliza y es sustituido por RAID 5. Nos gustara saber cual es vuestra recomendacin en base a la experiencia adquirida, ya que muchas veces la teora no transmite la realidad. Gracias por vuestra atencin, Atentamente, Joan Fontanillas Vila jfontanillas@agbar.es tel: 93-341-40-69

Hi- First off, consider using RAID1+0 instead of 0+1. (RAID0+1 is a mirror of stripes and RAID1+0 is a stripe of mirrors) RAID 1+0 is a better choice than RAID5 for random-write environments like Exchange. RAID 1+0 can flush the cache of Exchange's random write load 15-30% faster than RAID5. There are also other benefits like reduced rebuild times. Ignoring things like Write Coalescing RAID5 also has twice the I/O penalty that RAID1+0 has. Ask your storage experts to back up their claim that RAID5 had advanced to the point where it is better than RAID 1+0 with documentation from the vendor; If this is an EMC enviroment have them check out the "EMC CLARiiON Storage Solutions Microsoft Exchange 2003 Best Practices" guide on powerlink.emc.com as it clearly states that RAID1+0 is better. Documentation aside I've found that in recent installations the tide has definately swung from using RAID5 for the database files to RAID1+0 for database files; disk space has gotten cheaper and peformance over space utilization has become the deciding factor... at least for Exchange 2003...