Re: Lower Random Access Time vs RAID 0 / 1
От | Ron |
---|---|
Тема | Re: Lower Random Access Time vs RAID 0 / 1 |
Дата | |
Msg-id | E1HUOPX-0004DE-Ts@elasmtp-junco.atl.sa.earthlink.net обсуждение исходный текст |
Ответ на | Lower Random Access Time vs RAID 0 / 1 ("Michael Ben-Nes" <miki@epoch.co.il>) |
Список | pgsql-performance |
1= a better HD comparison resource can be found at www.storagereview.com http://www.storagereview.com/comparison.html You will find that storagereview has better information on any and all things HD than Tom's does. 2= DB servers work best with as many spindles as possible. None of your example configurations is adequate; and any configuration with only 1 HD is a data loss / data corruption disaster waiting to happen. In general, the more spindles the better with any DB. The =minimum= should be at least 4 HD's =dedicated= to the DB. OS HD's are independent and in addition to the 4+ DB HDs. 3= "heavy duty large DB with mostly reads and heavy write actions from time to time ( updates / huge transactions )." Does not have anywhere near the precision needed to adequately describe your needs in engineering terms. How big a DB? What % of the IO will be reads? % writes? How big is a "huge transaction"? Exactly what is the primary use case of this server? etc. We need =numbers= if we are going to think about "speeds and feeds" and specify HW. 4= =seriously= consider HW RAID controllers like 3ware (AKA AMCC) or Areca. with BB IO caches. You've got a lot more work ahead of you. Ron At 05:08 AM 3/22/2007, Michael Ben-Nes wrote: >Hello > >I plan to buy a new development server and I wonder what will be the >best HD combination. > >I'm aware that "best combination" also relay on DB structure and usage. >so lets assume, heavy duty large DB with mostly reads and heavy >write actions from time to time ( updates / huge transactions ). > >Here are the options: > >One very fast 10K RPM SATA Western Digital Raptor 150GB HD. > Pro: very low access time and generally 30% faster regarding mainstream HD. > Con: Expensive. > >2 mainstream 7.2K RPM SATA HD in RAID 0. > Pro: fast transfer rate. > Con: Access time is lowered as both HD has to sync for read / > write ( true ? ). > >2 mainstream 7.2K RPM SATA HD in RAID 1. > Pro: can access parallely different files in the same time ( true ? ). > Con: Slower at writing. > >Random access benchmark: ><http://www23.tomshardware.com/storage.html?modelx=33&model1=280&model2=675&chart=32>http://www23.tomshardware.com/storage.html?modelx=33&model1=280&model2=675&chart=32 > > >Will be happy to hear recommendations and ideas. > >Thanks, >Miki > >-- >-------------------------------------------------- >Michael Ben-Nes - Internet Consultant and Director. ><http://www.epoch.co.il>http://www.epoch.co.il - weaving the Net. >Cellular: 054-4848113 >--------------------------------------------------
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