Gentoo Archives: gentoo-user

From: Bryan Whitehead <driver@×××××××××.net>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] BIG reiserfs problem
Date: Mon, 30 Oct 2006 21:03:15
Message-Id: 45466788.1090602@megahappy.net
In Reply to: Re: [gentoo-user] BIG reiserfs problem by Bryan Whitehead
1 After sending this I realized that XFS doesn't support journal=data... I
2 thought journal=data was a general VFS part of the linux kernel... my
3 bad. :)
4
5 I guess you are just left with in kernel tuning (someone previously
6 posted a link to).
7
8 Bryan Whitehead wrote:
9 > If you are so concerned with the awesomeness of XFS's caching... why
10 > not turn on data-journaling? Then data (not just meta-data) is
11 > committed to the journal.
12 >
13 > You can also tune XFS to not wait so long to hold cached data.
14 >
15 > Alan McKinnon wrote:
16 >> On Saturday 28 October 2006 16:41, b.n. wrote:
17 >>
18 >>> Dale ha scritto:
19 >>>
20 >>>> If you use XFS, make sure you have good power. XFS does not like
21 >>>> power failures at all. I have had to reinstall on a second rig
22 >>>> because of this very problem. If you have a UPS, that may be OK.
23 >>>>
24 >>> Thanks a lot for the advice. Power outages do happen and I don't have
25 >>> an UPS. Why does it happen? Isn't XFS journaled?
26 >>>
27 >>
28 >> Yes it is journaled but it also allows data to be very aggressively
29 >> cached. Make that VERY aggressively cached. With the result that data
30 >> can be held in a huge cache somewhere and the kernel can be convinced
31 >> it has been written to disk.
32 >>
33 >> Consider XFS's pedigree - SGI wrote it for their graphics machines.
34 >> These were big monsters backed up with high grade UPSs and such - the
35 >> logic was that if you spend a brazillion bucks on hardware, a mega
36 >> UPS is part of the deal, along with the wages to pay the army of
37 >> admins you also need.
38 >>
39 >> And, when doing video rendering, it turns out that it's easier to
40 >> simply re-render a frame when the filesystems does something odd with
41 >> the data rather than go to the effort of writing an FS that is 100%
42 >> reliable. So SGI sacrificed something that doesn't actually matter
43 >> for their use case to gain a significant performace increase (which
44 >> does matter a great deal)
45 >>
46 >> alan
47 >>
48 >
49
50 --
51 gentoo-user@g.o mailing list

Replies

Subject Author
Re: [gentoo-user] BIG reiserfs problem Joshua Schmidlkofer <joshland@×××××.com>