Re: Looking for a cheap upgrade (RAID)

Поиск
Список
Период
Сортировка
От Josh Berkus
Тема Re: Looking for a cheap upgrade (RAID)
Дата
Msg-id 200305021510.25982.josh@agliodbs.com
обсуждение исходный текст
Ответ на Re: Looking for a cheap upgrade (RAID)  ("scott.marlowe" <scott.marlowe@ihs.com>)
Ответы Re: Looking for a cheap upgrade (RAID)
Список pgsql-performance
Scott,

> With that setup, you'd have 15 Gigs for the OS, 4 gigs for swap, and about
> 300 gigs for the database.  The nice thing about RAID 5 is that random
> read performance for parallel load gets better as you add drives.  Write
> performance gets a little better with more drives since it's likely that
> the drives you're writing to aren't the same ones being read.

Yeah, but I've found with relatively few drives (such as the minimum of 3)
that RAID 5 performance is considerably worse for writes than RAID 1 -- as
bad as 30-40% of the speed of a raw SCSI disk.   This problem goes away with
more disks, of course.

--
-Josh Berkus

______AGLIO DATABASE SOLUTIONS___________________________
                                        Josh Berkus
   Complete information technology     josh@agliodbs.com
    and data management solutions     (415) 565-7293
   for law firms, small businesses      fax 621-2533
    and non-profit organizations.     San Francisco


В списке pgsql-performance по дате отправления:

Предыдущее
От: "scott.marlowe"
Дата:
Сообщение: Re: Looking for a cheap upgrade (RAID)
Следующее
От: "scott.marlowe"
Дата:
Сообщение: Re: Looking for a cheap upgrade (RAID)