From: "Jure Pečar" <pegasus@nerv.eu.org>
To: linux-raid@vger.kernel.org
Subject: raid5 write performance
Date: Fri, 18 Nov 2005 15:05:43 +0100 [thread overview]
Message-ID: <20051118150543.59fbdfd9.pegasus@nerv.eu.org> (raw)
Hi all,
Currently zfs is a major news in the storage area. It is very interesting to read various details about it on varios blogs of Sun employees. Among the more interesting I found was this:
http://blogs.sun.com/roller/page/bonwick?entry=raid_z
The point the guy makes is that it is impossible to atomically both write data and update parity, which leaves a window of crash that would silently leave on-disk data+paritiy in an inconsistent state. Then he mentions that there are software only workarounds for that but that they are very very slow.
It's interesting that my expirience with veritas raid5 for example is just that: slow to the point of being unuseable. Now, I'm wondering what kind of magic does linux md raid5 does, since its write performance is quite good? Or, does it actually do something regarding this? :)
Niel?
--
Jure Pečar
http://jure.pecar.org
-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
next reply other threads:[~2005-11-18 14:05 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-11-18 14:05 Jure Pečar [this message]
2005-11-18 19:19 ` raid5 write performance Dan Stromberg
2005-11-18 19:23 ` Mike Hardy
2005-11-19 4:40 ` Guy
2005-11-19 4:57 ` Mike Hardy
2005-11-19 5:54 ` Neil Brown
2005-11-19 11:59 ` Farkas Levente
2005-11-20 23:39 ` Neil Brown
2005-11-19 19:52 ` Carlos Carvalho
2005-11-20 19:54 ` Paul Clements
2005-11-19 5:56 ` Guy
2005-11-19 19:30 ` raid5 reliability (was raid5 write performance) Carlos Carvalho
2005-11-20 0:27 ` Guy
-- strict thread matches above, loose matches on Subject: below --
2006-07-02 14:02 raid5 write performance Raz Ben-Jehuda(caro)
2006-07-02 22:35 ` Neil Brown
2006-08-13 13:19 ` Raz Ben-Jehuda(caro)
2006-08-28 4:32 ` Neil Brown
2007-03-30 21:44 ` Raz Ben-Jehuda(caro)
2007-03-31 21:28 ` Bill Davidsen
2007-03-31 23:03 ` Raz Ben-Jehuda(caro)
2007-04-01 2:16 ` Bill Davidsen
2007-04-01 23:08 ` Dan Williams
2007-04-02 14:13 ` Raz Ben-Jehuda(caro)
[not found] ` <17950.50209.580439.607958@notabene.brown>
[not found] ` <5d96567b0704161329n5c3ca008p56df00baaa16eacb@mail.gmail.com>
2007-04-19 8:28 ` Raz Ben-Jehuda(caro)
2007-04-19 9:20 ` Neil Brown
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20051118150543.59fbdfd9.pegasus@nerv.eu.org \
--to=pegasus@nerv.eu.org \
--cc=linux-raid@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).