Talk:Journaling file system

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Pros and Cons

The benefit of a journaling file system has been well made, but there is no section which specifically compares benefits with limitations. I don't want to attempt this myself on a subject I came to the page to find out about. (^_-)

But this page may give some ideas... http://support.apple.com/kb/HT2355 There is a section: "When Should Journaling Be Used?" which helped me. 88.96.159.86 (talk) 11:06, 4 June 2011 (UTC)[reply]

Spelling And Words

Properly this is a "Journalized" file system according to the dictionary (See OED entry for Journal and for Journalize). Journal(l)ing is a Linuxism and incorrect English 81.2.110.250 (talk) 23:17, 30 April 2008 (UTC)[reply]

GoBack

Would it be correct or incorrect to refer to the GoBack product as a Journaling file system? --Rebroad 14:38, 25 May 2005 (UTC)[reply]

No. It may use Journaling to accomplish what it does, but it's not a filesystem. It works on Windows so NTFS is the filesystem that it uses.

--08:00, 13 November 2005 (UTC)

Why Legacy P1 PCs cann't use ext3?

Could someone explain why my P1-266Mhz can't use ext3? I can install ext2 without errors, but ext3 always halts the Linux install process. I expect it is a bios issue. I recently tried to install a 250GB disk to expand my file system and was unable to partion anything over 8-GB. I know that some file systems will not work above 8-GB because of bios limitations. Any configuration clues would certainly help.

--1:45pm 25 Feburary 2006

Physical vs logical journalling

Theres an interesting comment on this issue by an ext3 developer, pointing out that logical journalling assumes disk block writes are atomic (they either happen or don't), whereas at least PC hardware is not so nice. <http://zork.net/~nick/mail/why-reiserfs-is-teh-sukc>. —The preceding unsigned comment was added by 217.64.116.8 (talk • contribs) 20:38, May 24, 2006 (UTC)

I'd be interested to see examples of Physical and Logical journalling. I know quite a lot of filesystems journal metadata, but FreeBSD's gjournal is the only example of full data journalling I'm aware of. —Preceding unsigned comment added by 87.81.140.128 (talk) 01:03, 26 August 2010 (UTC)[reply]

Why vs. What

Could someone please elucidate on the "Why" of journaled filesystems, in addition to the what and how?

Sources

Can anyone cite a paper or to on journaling?

Available Sources

Since the most commonly know use of journaling is in HFS+ file systems, it might be appropriate to cite the following document for this article.

http://docs.info.apple.com/article.html?artnum=107249 --Zerocool3001 20:31, 26 July 2007 (UTC)[reply]

Does HFS+ use journaling? I would bet that ext3 is the most common known use of journaling. —Preceding unsigned comment added by 77.212.20.61 (talk) 20:17, 13 September 2008 (UTC)[reply]

Moving, not solving problems?

Citation: A journaled file system maintains a journal of the changes it intends to make, ahead of time. After a crash, recovery simply involves replaying changes from this journal until the file system is consistent again.
- What I currently only see is that all problems of inconsistency are moved to the journal. What makes sure that the journal itself is not written to disk in an inconsistent manner? That is, when the system crashes (power loss etc.) while the journal is being written, isn't it left in an inconsistent state, giving rise to corrupt file systems the next time the journal is used to update the FS? --Abdull (talk) 09:54, 8 August 2008 (UTC)[reply]

If a journal is found to be inconsistent, it will just be ignored and nothing will be changed to the filesystem itself. I.e. the filesystem stays consistent. —Preceding unsigned comment added by 77.212.20.61 (talk) 20:19, 13 September 2008 (UTC)[reply]

cost?

I don't know much about this, but could there be a section on the cost of journaling? PDBailey (talk) 15:44, 7 April 2009 (UTC)[reply]

Technical detail needs some clarifying

"recovery simply involves reading the journal from the file system and replaying changes from this journal until the file system is consistent"

Where do you start reading the journal, that is, at what point? How is this determined? Is it possible to backtrack from the end to find the last change that had succeeded? Also, the fs is consistent by definition at all times. It's a question of performing the changes that weren't successful before the crash. --213.130.252.119 (talk) 01:21, 2 May 2010 (UTC)[reply]

Copy on Write filesystems not possible until BTRFS paper?

"... Such file systems, however, were not feasible until the recent discovery of the necessary copy-on-write-friendly data structures" and the reference to a 2009 paper on BTRFS is not accurate. ZFS was made available in November of 2005 and is a copy-on-write filesystem. Tpenta (talk) 06:58, 30 December 2010 (UTC)[reply]