From: Phil Turmel <philip@turmel.org>
To: Dallas Clement <dallas.a.clement@gmail.com>
Cc: John Stoffel <john@stoffel.org>,
Mark Knecht <markknecht@gmail.com>,
Linux-RAID <linux-raid@vger.kernel.org>
Subject: Re: best base / worst case RAID 5,6 write speeds
Date: Tue, 15 Dec 2015 14:52:39 -0500 [thread overview]
Message-ID: <56706F87.6030903@turmel.org> (raw)
In-Reply-To: <CAE9DZUS=AVydRoDZav-Mvq9VyPuM4Z+0iQgxy9KDJG9yB2NZ8g@mail.gmail.com>
On 12/15/2015 02:44 PM, Dallas Clement wrote:
> Wow! Thanks a ton Phil. This is incredibly helpful! It looks like I
> need to do some experimenting with smaller chunk sizes. Just one more
> question: what stripe cache size do you recommend for this system?
> It has 8 GB of RAM, but can't use all of it for RAID as this NAS needs
> to run multiple applications. I understand that in the >= 4.1 kernels
> the stripe cache grows dynamically.
I don't really know. I use the default 256, but all of my parity raid
arrays have 16k chunks and are relatively lightly loaded. Consider
sampling stripe_cache_active once a second for a normal workday on real
workloads to figure out what you need.
Phil
next prev parent reply other threads:[~2015-12-15 19:52 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-10 1:34 best base / worst case RAID 5,6 write speeds Dallas Clement
2015-12-10 6:36 ` Alexander Afonyashin
2015-12-10 14:38 ` Dallas Clement
2015-12-10 15:14 ` John Stoffel
2015-12-10 18:40 ` Dallas Clement
[not found] ` <CAK2H+ed+fe5Wr0B=h5AzK5_=ougQtW_6cJcUG_S_cg+WfzDb=Q@mail.gmail.com>
2015-12-10 19:26 ` Dallas Clement
2015-12-10 19:33 ` John Stoffel
2015-12-10 22:19 ` Wols Lists
2015-12-10 19:28 ` John Stoffel
2015-12-10 22:23 ` Wols Lists
2015-12-10 20:06 ` Phil Turmel
2015-12-10 20:09 ` Dallas Clement
2015-12-10 20:29 ` Phil Turmel
2015-12-10 21:14 ` Dallas Clement
2015-12-10 21:32 ` Phil Turmel
[not found] ` <CAK2H+ednN7dCGzcOt8TxgNdhdDA1mN6Xr5P8vQ+Y=-uRoxRksw@mail.gmail.com>
2015-12-11 0:02 ` Dallas Clement
[not found] ` <CAK2H+efF2dM1BsM7kzfTxMdQEHvbWRaVe7zJLTGcPZzafn2M6A@mail.gmail.com>
2015-12-11 0:41 ` Dallas Clement
2015-12-11 1:19 ` Dallas Clement
[not found] ` <CAK2H+ec-zMbhxoFyHXLkdM-z-9cYYzNbPFhn19XjTHqrOMDZKQ@mail.gmail.com>
2015-12-11 15:44 ` Dallas Clement
2015-12-11 16:32 ` John Stoffel
2015-12-11 16:47 ` Dallas Clement
2015-12-11 19:34 ` John Stoffel
2015-12-11 21:24 ` Dallas Clement
2015-12-11 23:30 ` Dallas Clement
2015-12-12 0:00 ` Dallas Clement
2015-12-12 0:38 ` Phil Turmel
2015-12-12 2:55 ` Dallas Clement
2015-12-12 4:47 ` Phil Turmel
2015-12-14 20:14 ` Dallas Clement
[not found] ` <CAK2H+edazVORrVovWDeTA8DmqUL+5HRH-AcRwg8KkMas=o+Cog@mail.gmail.com>
2015-12-14 20:55 ` Dallas Clement
[not found] ` <CAK2H+ed-3Z8SR20t8rpt3Fb48c3X2Jft=qZoiY9emC2nQww1xQ@mail.gmail.com>
2015-12-14 21:20 ` Dallas Clement
2015-12-14 22:05 ` Dallas Clement
2015-12-14 22:31 ` Tommy Apel
[not found] ` <CAK2H+ecMvDLdYLhMtMQbP7Ygw-VohG7LGZ2n7H+LAXQ1waJK3A@mail.gmail.com>
2015-12-14 23:25 ` Dallas Clement
2015-12-15 2:36 ` Dallas Clement
2015-12-15 13:53 ` Phil Turmel
2015-12-15 14:09 ` Robert Kierski
2015-12-15 15:14 ` John Stoffel
2015-12-15 17:30 ` Dallas Clement
2015-12-15 19:22 ` Phil Turmel
2015-12-15 19:44 ` Dallas Clement
2015-12-15 19:52 ` Phil Turmel [this message]
2015-12-15 21:54 ` John Stoffel
2015-12-15 23:07 ` Dallas Clement
2015-12-16 15:31 ` Dallas Clement
[not found] ` <CAK2H+eeD2k4yzuvL4uF_qKycp6A=XPe8pVF_J-7Agi8Ze89PPQ@mail.gmail.com>
2015-12-17 5:57 ` Dallas Clement
2015-12-17 13:41 ` Phil Turmel
2015-12-17 21:08 ` Dallas Clement
2015-12-17 22:40 ` Phil Turmel
2015-12-17 23:28 ` Dallas Clement
2015-12-18 0:54 ` Dallas Clement
[not found] ` <CAFx4rwT8xgwZ0OWaLLsZvhMskiwmY54MzHgnnEPaswByeRrXxQ@mail.gmail.com>
2015-12-22 6:15 ` Doug Dumitru
2015-12-22 14:34 ` Robert Kierski
2015-12-22 16:48 ` Dallas Clement
2015-12-22 18:33 ` Doug Dumitru
2016-01-04 18:56 ` Robert Kierski
2016-01-04 19:13 ` Doug Dumitru
2016-01-04 19:33 ` Robert Kierski
2016-01-04 19:43 ` Doug Dumitru
2016-01-15 16:53 ` Robert Kierski
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