Re: Recomended FS
От | Peter Childs |
---|---|
Тема | Re: Recomended FS |
Дата | |
Msg-id | Pine.LNX.4.58.0310201119140.22341@bluedragon.homelinux.net обсуждение исходный текст |
Ответ на | Re: Recomended FS (Nick Burrett <nick@dsvr.net>) |
Список | pgsql-general |
On Mon, 20 Oct 2003, Nick Burrett wrote: > Peter Childs wrote: > > > > On Mon, 20 Oct 2003, Shridhar Daithankar wrote: > > > >>A fast HD with a good RAID controller. Subject to budget, SCSI are beter buy > >>than IDE. So does hardware SCSI RAID. > >> > > > > I hate asking this again. But WHY? > > The duty cycle of SCSI drives is 100%. The duty cycle of IDE drives is > around 30-40%. Therefore one uses SCSI drives in mail and news servers > where disk access is more-or-less permanent. IDE drives usually degrade > or fail faster under such load. > > From experience I have noticed that IDE drives that initially perform > at 30Mbyte/sec dropped to around 10Mbyte/sec after a year or so. > > > What SCSI gain in spinning at 15000RPM and larger buffers. They > > lose in Space, and a slower bus. I would like to see some profe. Sorry. > > > > IDE Hard Disk 40Gb 7200RPM = 133Mbs = 50UKP > > SCSI Hard Disk 36Gb 10000RPM = 160Mbs = 110UKP > > On new servers doing a software RAID1 sync between two disks, I find the > following sustained transfer rates: > > SuperMicro 6013P-i ATA 133 80Gb IDE 7200rpm: 39000kbytes/sec. > SuperMicro 6013P-8 SCSI 320 72Gb SCSI 10000rpm: 65000kbytes/sec. > > The IDE drives are on seperate busses. The SCSI drives are on the same bus. > > I think that the 320Mhz SCSI busses are a bit faster than the 133Mhz ATA > busses. > > > > Is that extra 27Mbs worth another IDE Disk. and while you can get > > bigger faster SCSI disks prices go through the roof. Its no longer RAID > > but RAED (Redundant Array of Expensive Disks) > > > > My advise not that I've got any proof is that the money is better > > spent on a good disk controller and many disks than on each disk. > > > > In short if you have money to burn then by all means get SCSI but > > most people are better of spending > > I suppose that's your choice. Another way of looking that things is to > consider the worth the server has to your business and factor that into > how much you should consider spending on equipment. > > e.g. if the server can be attributed to £10,000/year, then perhaps a > cheap PC will do. If £1 million of your business relies on the server, > then perhaps you should look into investing more into it. > > At last somone who has the real answers that I thought ought to be true all the time. Its a shame nobody can give some hard and fast numbers that I can get the budget people to understand! Peter Childs
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