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gav616

Member

Registered: 2008-01-16

Posts: 182

[SOLVED] ext3 defaults to writeback not ordered?

I read it should default to ordered (for standard data recovery and performance), now I find out it doesn't, (unless I'm missing something....?.)

dmesg.log

EXT3 FS on sda3, internal journal
EXT3-fs: mounted filesystem with writeback data mode.

fstab

UUID=87f556fe-3df5-448e-bbbb-81ca8b908a48 /var    ext3 defaults,noatime            0 2 (sda3)
UUID=7c792232-bd6d-42c6-84c8-a960cdd8456d /home    ext3 defaults,noatime,data=journal    0 2

kernel26      2.6.30-5

Last edited by gav616 (2009-07-01 20:45:33)

sliponoga

Member

Registered: 2007-09-14

Posts: 38

Re: [SOLVED] ext3 defaults to writeback not ordered?

I read it should default to ordered (for standard data recovery and performance), now I find out it doesn't, (unless I'm missing something....?.)

$ gunzip -c /proc/config.gz | grep CONFIG_EXT3_DEFAULTS_TO_ORDERED
# CONFIG_EXT3_DEFAULTS_TO_ORDERED is not set

anrxc

Member

From: Croatia

Registered: 2008-03-22

Posts: 835

Website

Re: [SOLVED] ext3 defaults to writeback not ordered?

I read it should default to ordered (for standard data recovery and performance), now I find out it doesn't

From Linux 2.6.30 writeback is default for ext3, read my old post to learn more about it and how not to break your system when returning to ordered.

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You need to install an RTFM interface.

gav616

Member

Registered: 2008-01-16

Posts: 182

Re: [SOLVED] ext3 defaults to writeback not ordered?

I read it should default to ordered (for standard data recovery and performance), now I find out it doesn't

From Linux 2.6.30 writeback is default for ext3, read my old post to learn more about it and how not to break your system when returning to ordered.

thank you for the info, I guess I'll leave it like it is, apart from, I think I'll keep journal mode for my /home because I use amule and if my system crashes I don't want to lose downloaded chunks.

Just out of interest, why is 'writeback' now default? has it been improved?

Last edited by gav616 (2009-07-01 15:26:58)

shining

Pacman Developer

Registered: 2006-05-10

Posts: 2,043

Re: [SOLVED] ext3 defaults to writeback not ordered?

I read it should default to ordered (for standard data recovery and performance), now I find out it doesn't

From Linux 2.6.30 writeback is default for ext3, read my old post to learn more about it and how not to break your system when returning to ordered.

thank you for the info, I guess I'll leave it like it is, apart from, I think I'll keep journal mode for my /home because I use amule and if my system crashes I don't want to lose downloaded chunks.

Just out of interest, why is 'writeback' now default? has it been improved?

I don't know what was wrong with it before.

But it became the default because it has a much better latency than ordered now :
http://lkml.org/lkml/2009/4/6/331

EDIT : some other links
quick summary of fs changes in 2.6.30 : http://kernelnewbies.org/Linux_2_6_30#h … 18cdd6630d
bigger explanation, in particular of data=writeback : http://lwn.net/Articles/326471/

Last edited by shining (2009-07-01 16:10:35)

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pacman roulette : pacman -S $(pacman -Slq | LANG=C sort -R | head -n $((RANDOM % 10)))

gav616

Member

Registered: 2008-01-16

Posts: 182

Re: [SOLVED] ext3 defaults to writeback not ordered?

From Linux 2.6.30 writeback is default for ext3, read my old post to learn more about it and how not to break your system when returning to ordered.

thank you for the info, I guess I'll leave it like it is, apart from, I think I'll keep journal mode for my /home because I use amule and if my system crashes I don't want to lose downloaded chunks.

Just out of interest, why is 'writeback' now default? has it been improved?

I don't know what was wrong with it before.

But it became the default because it has a much better latency than ordered now :
http://lkml.org/lkml/2009/4/6/331

EDIT : some other links
quick summary of fs changes in 2.6.30 : http://kernelnewbies.org/Linux_2_6_30#h … 18cdd6630d
bigger explanation, in particular of data=writeback : http://lwn.net/Articles/326471/

*nods*