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RampantAI · 06:04 PM

When 10.3 is released on that date in October should journalling be turned on or off at what are the benefits and draw downs of doing so...

I have been told it is turned on by default when partitoning with the install disk....

benb · Oct 9, 2003, 04:03 PM

I would use HFS+ Journaled. You will take a minor speed hit in writes, about 5%. Well worth it IMO.

NeXTLoop · Oct 9, 2003, 04:04 PM

It should be the same as it currently is. 10.2 has had journaling for several revisions now. It basically allows your system to more easily recover from a crash without data loss. The downside is that it can cause minimal decreases in speed if you're doing things that involve a lot of writing to disk.

I've not ran any version of Panther, but I can't really see anything being any different that it currently is.

mikemako · Oct 9, 2003, 05:30 PM

In what way is data protected with a journaled system? Does that mean if you're working on a Word document and the machine crashes that the document will be saved? Where would a modest user notice the benefits of journaling?

CatOne · Oct 9, 2003, 05:47 PM

Originally posted by mikemako:
In what way is data protected with a journaled system? Does that mean if you're working on a Word document and the machine crashes that the document will be saved? Where would a modest user notice the benefits of journaling?

No. Journaling is not data protection. Journaling just makes sure that file system changes are "logged" so that it can be "played back" and synched to a "known" state if the system shuts down uncleanly (i.e. kernel panic or you press and hold the power button for 5 seconds or pull the battery out).

Without journaling, OS X runs 'fsck' when you start up (which is why the system can sit at the "grey apple" page for 1 minute extra after an unclean shutdown). With journaling, it can just "play forward the journal" and rewrite changes to the file tables, taking about a second. So the net observable change to the end user would be reboots after improper shutdown would be faster. That's it. No data protection.

Now keep in mind if you had a server with an Xserve RAID with 2 TB of storage attached to it, and shut it down improperly, it could take HOURS to run 'fsck.' And that would really stink

But really that's why journaling was present on the server before the client -- the benefits were much more readily apparent.

Just don't think it's going to help you save user data -- it is NOT. It could keep your disk from getting horribly corrupted in a bad way, if the file table somehow got munged and 'fsck' couldn't fix it (which is rare).

barbarian · Oct 9, 2003, 05:51 PM

I like journaling in theory, but none of the disk repair utilities seem to be updated for journaling yet. This scares me.

mikemako · Oct 9, 2003, 05:55 PM

Thank you for the above response, that was very informative and helpful!

Now, regarding this:

Originally posted by NeXTLoop:
It should be the same as it currently is. 10.2 has had journaling for several revisions now.

I'm not sure if this is correct, or perhaps what you mean is that Jaguar has the ability to journal (but by default the feature is off). In Jaguar, I could run "fsck -y" when booted into single user mode, but if I try to run that in Panther, I will receive a message saying something like: "this file system is journaled, there is no need to run 'fsck y'".

JB72 · Oct 9, 2003, 06:03 PM

Is there anything different or improved in the journaling in Panther vs. Jaguar? And, just to clarify, it is enabled on a per disk basic right? So I could leave media drives unjournaled as not to harm their write speed.

diamondsw · Oct 9, 2003, 06:08 PM

Originally posted by barbarian:
I like journaling in theory, but none of the disk repair utilities seem to be updated for journaling yet. This scares me.

No changes should be needed - the journal is automatic. By the time a disk utility sees the disk, any journal entries have been replayed. FYI, DiskWarrior works great here on journaled volumes.

diamondsw · Oct 9, 2003, 06:09 PM

Originally posted by mikemako:
Thank you for the above response, that was very informative and helpful!

Now, regarding this:

I'm not sure if this is correct, or perhaps what you mean is that Jaguar has the ability to journal (but by default the feature is off). In Jaguar, I could run "fsck -y" when booted into single user mode, but if I try to run that in Panther, I will receive a message saying something like: "this file system is journaled, there is no need to run 'fsck y'".

It should do the same on Jaguar. If a volume is journaled you have to force the fsck with the -f option, so:

fsck -fy

Will do it.

mikemako · Oct 9, 2003, 06:20 PM

Yes, I know Jaguar has the ability to journal, but the statement seemed to imlpy that it was a feature that has been active since then. I was just clarifying that *now* it is on by default and in Jaguar it was not. Perhaps I misunderstood the poster's intent.

michael_on_mac · Oct 9, 2003, 07:07 PM

Talking about journaling..

Does any of you know if there's a way to mount -uuh- more established - filesystems like ReiserFS, ext3 or JFS in OSX?

I have quite some data under those systems on FW disks.

Thanks, Michael.

yukon · Oct 9, 2003, 07:26 PM

despite fsck's adversion to checking a journaled disk, still do it (the -f switch). i've found minor corruption on a number of occasions, on my one machine.

barbarian · Oct 9, 2003, 08:38 PM

No utiliites for mounting JFS, ext3, or ReiserFS... yet. You can mount ext2 filesystems using some 3rd party utilites:

http://www.classicalguitar.net/brian/software/

----
and of course there us UFS whis is built in as well as support for the various windows file systems.

====
FYI:

Linux can mount HFS directly.
NetBSD can mount hfs & hfs+ with hfsutils.

hfsutils can also be used with Linux for hfs+

BurpetheadX · Oct 9, 2003, 09:31 PM

http://docs.info.apple.com/article.html?artnum=107249

Mac OS X Server 10.2.2 provides a journaling feature for the Mac OS Extended (HFS Plus) file system that enhances server availability and fault resilience. Journaling protects the integrity of the file system on Xserve and other computers using Mac OS X Server in the event of an unplanned shutdown or power failure. It also helps to maximize the uptime of servers and connected storage devices by expediting repairs to the affected volumes when the system restarts.

Journaling is a technique that helps protect the integrity of the Mac OS Extended file systems on Mac OS X Server volumes. It both prevents a disk from getting into an inconsistent state and expedites disk repair if the server fails.

When you enable journaling on a disk, a continuous record of changes to files on the disk is maintained in the journal. If your server stops because of a power failure or some other issue, the journal is used to restore the disk to a known-good state when the server restarts.

With journaling turned on, the file system logs transactions as they occur. If the server fails in the middle of an operation, the file system can "replay" the information in its log and complete the operation when the server restarts.

Although you may experience loss of user data that was buffered at the time of the failure, the file system is returned to a consistent state. In addition, restarting the computer is much faster. Always remember to back up your data as frequently as necessary.

Why is journaling needed?

A power outage or system failure interrupts read and write processes, which can cause discrepancies between the file system directory and the actual location and structure of stored files. In an unjournaled file system, drives are in an unknown state after a failure, meaning that there is no record of their activity just prior to the shutdown. Before the server can restart and resume services, it must perform a consistency check that requires going through the entire file system, block by block. This process can take hours on a multi-terabyte volume, resulting in an unacceptable period of server downtime.

Journaling in Mac OS X Server accelerates the recovery time after an unexpected shutdown, significantly improving the availability of server and storage systems. When journaling is turned on on a storage volume, the server automatically tracks file system operations and maintains a continuous record of these transactions in a separate file, called a journal. The operating system can use the journal to return the file system to a known, consistent state after a failure. This eliminates the need to perform a consistency check on the entire file system during startup. Instead, when the server is restarted, Mac OS X Server simply replays recent transactions in the journal, bringing the system up-to-date and resuming operations that were interrupted during the failure. With a journaled file system, server restart takes just a few seconds, regardless of the number of files, or the size of the volume.

Backward Compatible

Journaled file system is part of a set of incremental enhancements to the Mac OS Extended file system, and it is backward compatible with the Mac OS Extended file system. Users can read, write, and access journaled Mac OS Extended volumes on computers that do not have a journaling feature.

Most disk utilities designed to work with the Mac OS Extended file system can also be used when journaling is turned on. You should check with your disk utility vendor before using earlier disk utilities with a journaled file system.

When Should Journaling Be Used?

Journaling is best suited for servers requiring high availability, servers containing volumes with many files, and servers containing data that is backed up at infrequent intervals (nightly, for example).

If a volume contains read-only data that is not mission-critical, it may not be necessary to turn on journaling if performance is more important than safety.

If your server contains high-bandwidth usage data files, such as large video, graphics, or audio files, you may want to weigh the benefits of using journaling against the performance needed to access your data. In most cases, the impact of journaling upon data access performance are unnoticeable to users, but its implementation may not be practical for servers where data access demands outweigh its benefits.

Booyah.

CatOne · Oct 9, 2003, 10:16 PM

Originally posted by barbarian:
No utiliites for mounting JFS, ext3, or ReiserFS... yet. You can mount ext2 filesystems using some 3rd party utilites:

http://www.classicalguitar.net/brian/software/

----
and of course there us UFS whis is built in as well as support for the various windows file systems.

====
FYI:

Linux can mount HFS directly.
NetBSD can mount hfs & hfs+ with hfsutils.

hfsutils can also be used with Linux for hfs+

Note, you can NOT use journaling on a UFS volume in Panther. Nor can you in Jaguar.

barbarian · Oct 9, 2003, 11:44 PM

>Note, you can NOT use journaling on a UFS volume in Panther. Nor can you in Jaguar.

I didn't mean to imply that you could use journaling on UFS, just that you could access UFS volumes from Journaled HFS+....

danengel · Oct 10, 2003, 04:58 AM

Do I have to reformat my disk to enable journalling? I wouldn't want to...

P · Oct 10, 2003, 04:59 AM

Originally posted by barbarian:
No utiliites for mounting JFS, ext3, or ReiserFS... yet. You can mount ext2 filesystems using some 3rd party utilites:

http://www.classicalguitar.net/brian/software/

----
and of course there us UFS whis is built in as well as support for the various windows file systems.

====
FYI:

Linux can mount HFS directly.
NetBSD can mount hfs & hfs+ with hfsutils.

hfsutils can also be used with Linux for hfs+

ext3 is just ext2 with an optional journal. ext3 volumes will mount using the above ext2 extension, but journalling wuill be disabled.

bracken · Oct 10, 2003, 05:29 AM

Originally posted by danengel:
Do I have to reformat my disk to enable journalling? I wouldn't want to...

No.
On = sudo diskutil enableJournal /
Off = sudo diskutil disableJournal /

...

With my iBook and it's slow, laptop hard drive I've found that Panther's journaling is faster than Jaguar's. When journaling was on with Jaguar I was getting quite a lot of spinning beach balls of death. I don't notice any slow-down with Panther.

Millennium · Oct 10, 2003, 08:35 AM

Originally posted by benb:
I would use HFS+ Journaled. You will take a minor speed hit in writes, about 5%. Well worth it IMO.

Actually, even this depends on what you are doing. If you tend to work with many small files at once, journaling can actually speed up your machine.

How is this possible, you ask? One of the ways journaling works is to group writes together. So, for example, ten 1K writes might be grouped into one 10K write of all the files at once (this example is a bit simplistic, but the principles are accurate). This makes the journal much easier to manage for the computer, but it also has an interesting side effect: because it's all written out at once, you only have to reposition the drive heads one time, instead of ten times. Because moving the drive heads is a relatively slow process, and the drive can't do any writes while it's doing that, you save more time than you lose because of the extra journaling. End result: a net speed boost.

Also, as others have mentioned, journaling does not protect individual files. It only makes sure that the filesystem itself cannot be corrupted by ordinary means. In addition to speeding things up, there are some privacy concerns with full-data journaling, which metadata-only journaling alleviates.

Bottom line: you still have to back up your files. Journaling can't save you from extraordinary circumstances, like a power surge frying your hard drive, or the building burning down, or anything. So the old song still applies (to the tune of "If You're Happy and You Know It"):

If you can't afford to lose it back it up (clap clap)
If you can't afford to lose it back it up (clap clap)
If you can't afford to lose it
Then there's no way to excuse it
If you can't afford to lose it back it up (clap clap)

tooki · Oct 10, 2003, 08:55 AM

Originally posted by barbarian:
I like journaling in theory, but none of the disk repair utilities seem to be updated for journaling yet. This scares me.

Originally posted by diamondsw:
No changes should be needed - the journal is automatic. By the time a disk utility sees the disk, any journal entries have been replayed. FYI, DiskWarrior works great here on journaled volumes.

You're both wrong.

There is a utility that is updated to take advantage of journaling.

Utilities DO need to be updated to be even just journal-aware!

Norton just crashes when it sees a journal. We Won't Talk About That Program.

DiskWarrior 2.x (the OS 9 version) is not journal-aware, and will destroy the journal if present. It will not damage data, but it doesn't know what to make of the journaling data stored on the drive, and "fixes" it.

DiskWarrior 3 (the OS X version) is not only journal-aware, it will use the journal to help rebuild the directory. So if there's anything left in the journal (e.g. if you run DW right after a crash), it will use that data to create the clean directory.

Journaling can be enabled/disabled on the fly. The command line is one way to do it. In OS X Server and Panther, you can also just choose a checkbox in Disk Utility.

tooki

eevyl · Oct 10, 2003, 08:58 AM

Originally posted by bracken:
No.
On = sudo diskutil enableJournal /
Off = sudo diskutil disableJournal /

You can enable journaling in the new Disk Utility application that comes with Panther.

diamondsw · Oct 10, 2003, 06:00 PM

Originally posted by tooki:
You're both wrong.

There is a utility that is updated to take advantage of journaling.

Utilities DO need to be updated to be even just journal-aware!

Norton just crashes when it sees a journal. We Won't Talk About That Program.

DiskWarrior 2.x (the OS 9 version) is not journal-aware, and will destroy the journal if present. It will not damage data, but it doesn't know what to make of the journaling data stored on the drive, and "fixes" it.

DiskWarrior 3 (the OS X version) is not only journal-aware, it will use the journal to help rebuild the directory. So if there's anything left in the journal (e.g. if you run DW right after a crash), it will use that data to create the clean directory.

Journaling can be enabled/disabled on the fly. The command line is one way to do it. In OS X Server and Panther, you can also just choose a checkbox in Disk Utility.

tooki

Thanks for illuminating the issue!

Also, journaling only protects you from crashes, sudden halts, etc. If there is a bug in the OS and it decides to write strange data over your directory, the journal won't prevent that. (Only reason I say it is I lost a drive last month when something went and simultaneously corrupted the volume header and alternate volume header.

)

moonmonkey · Oct 11, 2003, 05:39 AM

Originally posted by barbarian:
I like journaling in theory, but none of the disk repair utilities seem to be updated for journaling yet. This scares me.

Diskwarrior is.

VEGAN · Oct 11, 2003, 06:10 AM

Originally posted by barbarian:
No utiliites for mounting JFS, ext3, or ReiserFS... yet. You can mount ext2 filesystems using some 3rd party utilites:

http://www.classicalguitar.net/brian/software/

----
and of course there us UFS whis is built in as well as support for the various windows file systems.

====
FYI:

Linux can mount HFS directly.
NetBSD can mount hfs & hfs+ with hfsutils.

hfsutils can also be used with Linux for hfs+

There was a study [an article on "slashdot"] about different formats and ext3 did the worse... so...

HiRez · Oct 11, 2003, 06:37 AM

Originally posted by tooki:
Journaling can be enabled/disabled on the fly. The command line is one way to do it. In OS X Server and Panther, you can also just choose a checkbox in Disk Utility.

Can this be done on a per-partition basis, or only per-disk? If I had one partition with all my system stuff on it, and another with my user folder (containing media files), it seems it might be nice to journal the system partition to protect it, but leave my files unjournaled, since I need high performance from them.

CharlesS · Oct 11, 2003, 01:28 PM

If you can't afford to lose it back it up (clap clap)
If you can't afford to lose it back it up (clap clap)
If you can't afford to lose it
Then there's no way to excuse it
If you can't afford to lose it back it up (clap clap)

Am I the only one that finds this song somewhat rude and patronizing?

ngrundy · Oct 11, 2003, 01:44 PM

Originally posted by CharlesS:
Am I the only one that finds this song somewhat rude and patronizing?

Maybe, mabye not I actually found it quite amusing, but it does ring true, all too true. There is no good excuse not to back up.

BigYellowMonkey · Oct 11, 2003, 08:50 PM

Yes, DiskWarrior 3 for OS X does recognize journaling. And it will allow you to rebuild the directory of a journaled drive.
Drive 10 does recognize journaling, and will allow you to rebuild the directory, but will not allow you to optimize your drive. Which is a bit of a disappointment.

-Biggie!

tooki · Oct 12, 2003, 10:34 AM

Originally posted by CharlesS:
Am I the only one that finds this song somewhat rude and patronizing?

Yep.

Every computer user should be taught that rhyme.

tooki