[snip] > However, typically most of the data you access is cached in > memory, especially if you have huge amounts of memory and do > OLTP instead of Data Warehousing. In this scenario write > performance of disks becomes important (Transaction Log > etc.). Write performance of Raid 10 is better than write > performance of Raid 5.
Agree.. > Another point is: use as many disks as possible to > parallelize the I/O. Oracle (v. 8) for example uses 22 (!) > Harddisks in an optimal Installation scenario confirming to > OFA (Oracle Flexible Architecture for a growing database). aubir3p1:sqdp01 133> dbmcli -U c param_getdevsall OK LOG_MODE DUAL MAXARCHIVELOGS 2 MAXDATADEVSPACES 24 MAXDATAPAGES 51099008 ARCHIVE_LOG_001 960000 R /sapdb/P01/saplog/DISKL001 M_ARCHIVE_LOG_001 R /sapdb/P01/saplog/M_DISKL001 DATADEV_0001 2221696 R /sapdb/P01/sapdata/DISKD0001 DATADEV_0002 2221696 R /sapdb/P01/sapdata/DISKD0002 DATADEV_0003 2221696 R /sapdb/P01/sapdata/DISKD0003 DATADEV_0004 2221696 R /sapdb/P01/sapdata/DISKD0004 DATADEV_0005 2221696 R /sapdb/P01/sapdata/DISKD0005 DATADEV_0006 2221696 R /sapdb/P01/sapdata/DISKD0006 DATADEV_0007 2221696 R /sapdb/P01/sapdata/DISKD0007 DATADEV_0008 2221696 R /sapdb/P01/sapdata/DISKD0008 DATADEV_0009 2221696 R /sapdb/P01/sapdata/DISKD0009 DATADEV_0010 2221696 R /sapdb/P01/sapdata/DISKD0010 DATADEV_0011 2221696 R /sapdb/P01/sapdata/DISKD0011 DATADEV_0012 2221696 R /sapdb/P01/sapdata/DISKD0012 DATADEV_0013 2221696 R /sapdb/P01/sapdata/DISKD0013 DATADEV_0014 2221696 R /sapdb/P01/sapdata/DISKD0014 DATADEV_0015 2221696 R /sapdb/P01/sapdata/DISKD0015 DATADEV_0016 2221696 R /sapdb/P01/sapdata/DISKD0016 DATADEV_0017 2221696 R /sapdb/P01/sapdata/DISKD0017 DATADEV_0018 2221696 R /sapdb/P01/sapdata/DISKD0018 DATADEV_0019 2221696 R /sapdb/P01/sapdata/DISKD0019 DATADEV_0020 2221696 R /sapdb/P01/sapdata/DISKD0020 DATADEV_0021 2221696 R /sapdb/P01/sapdata/DISKD0021 DATADEV_0022 2221696 R /sapdb/P01/sapdata/DISKD0022 That's our production system on RAW devices. DATA is on RAID-5 and LOG on RAID-1. This is on an external SAN with 42 harddisk where 32 are used at the moment. > I also would consider to buy Sun Hardware and use Solaris > instead of Intel/Linux if you have the budget, since that > architecture scales much better than Intel. Scale in what sense? The _only_ advantages I see are 64bit'ting for memory addressing and > 8 CPUs. SUNs have PCI too (the mid size ones) and I doubt, that RISC would make _that_ big difference for our installation. If I see that an installation of WAS 6.20 takes double as long on a decent SUN than on a comparable Linux box I don't see the benefit for this $$$ machines :-) At the moment we are not as big that we need that but time will tell... :-) Ah, and this is also Linux/Intel - avg. Response time: < 450 ms. -- Markus Doehr SIEGENIA-AUBI KG CCC - SAP R/3 Basis, SAPDB-DBA Zum Grafenwald fon: +49 6503 917 152 D-54411 Hermeskeil fax: +49 6503 917 190 http://www.siegenia-aubi.com _______________________________________________ sapdb.general mailing list [EMAIL PROTECTED] http://listserv.sap.com/mailman/listinfo/sapdb.general
