Gentoo Archives: gentoo-user

From: James <wireless@×××××××××××.com>
To: gentoo-user@l.g.o
Subject: [gentoo-user] Re: jbd2 keeps spinning my disk up
Date: Mon, 01 Aug 2011 18:34:47
In Reply to: [gentoo-user] jbd2 keeps spinning my disk up by Peter Humphrey
1 Peter Humphrey <peter <at>> writes:
4 > My little Atom box's hard disk spins up every minute or so, and watching
5 > iotop I see it's jbd2 that does it.
7 > Google shows that others have similar problems.
9 > Before I re-create all the partitions as reiserfs - and remove ext4 from the
10 > kernel - does anyone have a lighter solution?
12 Well, lots in good responses, so please do not interpret
13 mine as saying it's a better solution that what
14 others are suggestion.
16 Atom is more of an embedded processor than
17 a true workstation/server processor, imho.
18 As such, it it more "bare metal" meaning
19 countless software developments for AMD and
20 Intel processors intended for workstations
21 and servers, are irrelevant, useless, harmful,
22 redundant, or just plain stupid for embedded
23 processors. like the atom.
25 So now you (and I and millions of folks) are
26 trying to use mega-software (linux distro)
27 on a bare-metal processor....
29 NOBODY has fleshed out these issues on an itemized
30 basis. i.e. the knowledge base is sparse (at best)
31 since the only one that can really do this is the
32 silicon vendors and they have a VESTED INTEREST
33 in not doing so. Furthermore, since Atom and ARM
34 and many other embedded processors are combined
35 as "cores" on an SOC (system on a chip) each
36 revision of such hardware by each vendor can have
37 different addtional hardware on the SOC that a generic
38 compiled software distro is clueless about.
39 That's why numerous devices
40 that attempt low power linux, use a proprietary
41 linux based on montaVista or countlesss other
42 embedded linux vendors. These purveyors and vendors
43 of the various embedded linux offerings do not
44 publish anything about these hardware details
45 for some issues and do include documentation,
46 deep in the specifications of the processor.
48 When you stray from that (the linux distro that
49 come with the product), you are on your own,
50 finding piecemeal information about low level
51 hardware
52 If the device came with some OS other than a
53 linux hack..... YOu are much futher from
54 paradise then with a default linux distro
55 as the OS the vendor provided. It does not mean
56 you will not be successful, just your journey
57 is perilous, at best, if optimization is
58 what you seek.
61 Long story short, for years I have been building
62 firewalls and embedded linux bridges, sniffers
63 and other passive ethernet based devices,
64 using ext2. Works beautifully with little
65 attention. Not optimized, but avoid a HUGE
66 time-sink.
68 I encounter a myriad of issues, when trying
69 newer file systems for embedded linux systems.
70 Ext-2 works for years on Compact Flash drives
71 if you do not log, or limit logs to an NFS link
72 or such. As one reader suggested, you have to
73 audit, one application at a time, to find the culprit.
74 It's actually a never ending process, imho,
75 as feature creep on a myriad of software packages
76 will usually lead to performance issues and thus
77 more aggressive algorithms on data movement.
79 You may want to try some of the file systems
80 intended for embedded system (as part of the
81 newer linux kernels) and the tuning
82 parameters therein, if you are looking for
83 a robust solution. Also delete what you do
84 not need from the atom based system, just
85 as a general policy. Minimal and embedded
86 are different facets of the same thing.
88 Intel atom is first and foremost an embedded
89 processor, not a CISC processor. I.E. just
90 because it compiles, does not mean it runs
91 well on limited resources or bare metal.
94 Happy Hunting,
95 James