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Firewire Conundrums

(Originally called Firewire bug page. Changed the name of the problem for better clarity)
As of June 19, 2010, many of the manufacturer links below are no longer valid. If you have newer links for them, please feel free to offer us feedback.

In Mac OS X 10.5.2, there are some instances where the Finder may not load with External hard drives according to the Apple knowledgebase

In Mac OS X 10.4.9, it was found that Western Digital MyBook drives put an unsupported addon for their drives to use in Macintosh HD -> Library -> Launch Daemons called com.WD.WDDriveServices.plist. Removing that file fixes the ability of those drives to be read.

Starting with Mac OS X 10.3, it became apparent that the firmware of a Firewire hard drive case needed to be upgraded to avoid not being able to be read by Mac OS X in some cases. Turns out that this is not the only cause of a non-hardware related issue that could cause Firewire hard drives to be readable on some machines yet not others when using the same Firewire cables. It has been found that these causes are the most likely and should be tested for in this order:

1. The PRAM needs zapping. Note, if a machine is 3 or more years old, PRAM zapping should only be attempted after verifying that the PRAM battery (also known as backup battery) is fully charged. Similarly, the NVRAM may need resetting.

2. The firewire ports need resetting, or the PMU needs resetting.

3. Spotlight indexing on the hard drive needs turning off. This is only an issue under 10.4 (Mac OS X Tiger). For more on why this may be an issue see the section on this FAQ on 10.4 Issues.

4. Dust in the firewire ports.

5. Installed firmware on the Firewire bridge of the hard drive is not fully compatible with the operating system. Check the manufacturer's support line (in this case e-mail firewire AT for updated firmware.

6. The operating system's Firewire drivers are not properly installed. This may happen if you used system specific disks for another Mac to install the operating system, or the directory is damaged, or the preferences for the firewire are not working.

10.4 issues

It does appear that Spotlight can kernel panic on some drives such as a Coolgear drive if the search results are somewhere over 20,000 to 37,000 results. In addition, Spotlight may sometimes render information on drives it is indexing invisible (while still making the drive visible in the Finder) until the index is complete. Go to Apple menu -> System preferences -> Spotlight, and select Privacy and drag the drive into the Privacy Pane to stop its indexing of the drive if you notice in its menu (the blue circle with white magnifying glass in the upper right corner) that it is indexing that drive. Whether the kernel panic mentioned earlier is an actual bug, or just the kernel being overwhelmed by information I'm still testing. It is highly recommended you dismount and disconnect all Firewire devices before you update to any Mac OS X, as several have reported losing access to their drive. Whether there was a hardware problem, directory problem, or they haven't updated their firmware has yet to be determined.

Reset the Firewire bus

Apple does have a nice Article on how to reset the Firewire ports as a first line of defense if your Firewire isn't recognizing any device. A solution which has worked for some whose hard drive became invisible in 10.4 was simply to follow these four steps to reset the Firewire bus:
1. Shut the machine down.
2. UNPLUG the power lead to the computer and the firewire drive.
3. leave it for 10 minutes.
4. Connect back up and reboot.

Special thanks to a LaCie technician for bringing this up on Apple Discussions.

NVRAM resetting

Former reports on Macintouch suggest that resetting the NVRAM can help as well.

Reset the PMU

In addition, Resetting the PMU (Instructions for Mac Mini, PowerMac G4 AGP/Gigabit, iMac G4, Powerbook/iBook, eMac) has been shown to be effective, though this procedure if done wrong can sometimes lead some machines more inaccessible than before. If you are uncertain you can do this task safely, ask an authorized service technician to do it.

Firmware updates

Beginning with Mac OS X 10.3, it became apparent that the firmware may need updating New firmware conundrum with 10.3.6 through 10.3.9: If you have a Part 2 research firewire/IDE bridgeset you may see similar problems to the conundrum below. See the MacAlly and Initio footnotes below as well. If your drive uses another chipset, contact the vendor to verify that it has updated its firmware to address these issues. It has been found the firmware of these drives would upon 10.3.6 through 10.3.9's installation go bad. The only way to prevent it for those drives is not have the drive connected during the installation of 10.3.6 through 10.3.9. The drive does not have to be turned on for the problem to surface, it merely has to be connected. Firmware updates are slowly coming to the fore and should be requested by the vendors who made the Firewire hard drive case for your problem to be resolved. Apple also had a statement on the 10.3.7 update page which said:
Important: Please read before installing

If you have a third-party FireWire hard drive connected, turn it off and disconnect it before installing this update. Reconnect it and turn it back on after installation is complete and you've restarted.

The 10.3.8 and 10.3.9 combined update says:
Important: Please read before installing
If you have a third-party FireWire hard drive connected, disconnect it before installing this update. Reconnect in reverse order of the disconnect link and turn it back on after installation is complete and you've restarted.
This follows the advice issued with the 10.3.6 update above for Initio, MacAlly, and Part 2, and why the rest of this FAQ assumes it is the same problem with 10.3.7 and 10.3.9. If there is evidence to contradict this, please sign my guestbook.

It is not directly linked in any shape to the conundrum experienced by people in 10.3.0 to 10.3.6 (at this time it is unknown if 10.3.7 through 10.3.9 addresses the Oxford 911 and 922 problems) with Oxford 911 and 922 chipsets. Neither is it related to the Firewire/USB/RAID conundrum

This page describing the is divided into these sections:
The summary | Tips for avoiding conundrum | Apple's Important Note | Manufacturers who have addressed the conundrum in some fashion | Manufacturers with unknown status | Footnotes

Summary of conundrum

The following is an updated version of the user contributed FAQ on Apple's website due to that site's space limitations on user contributed FAQs:

Mac OS X 10.3 through Mac OS X 10.3.6 (at this time the Oxford issue is unknown whether it exists with 10.3.7 through 10.3.9) also known as Panther under certain conditions may cause data to get lost on Firewire hard drives. Apple updated the Firewire drivers when creating Panther, resulting in the need of hard drive manufacturers to update the firmware of the cases that have the bridge between IDE and Firewire. If you were to open almost any Firewire hard drive, you'll notice that it contains an IDE drive and a bridge board to connect the IDE to the Firewire ports. It is this board whose firmware version is in question. This affects:

Oxford 911 Firewire (IEEE 1394, now has been renamed IEEE 1394a for Firewire 400 models) 400, Oxford 922 Firewire 800 (IEEE 1394b). Users have reported problems also with target disk mode as well.

The problem occurs if the drive is connected to the computer during restart, shutdown, or a sleep that can't wake which forces a restart, and startup.

Tips for avoiding the conundrum

Backup your data religiously. Make duplicate backups prior to applying any software update. Repair permissions before and after any software update with Mac OS X. And most important, do not upgrade with the hard drive attached to the computer. It has been found that if the hard drive is attached to the computer at least with the conundrum faced by 10.3.6 through 10.3.9 users, that the drive will in fact become unreadable after the update. The drive does not have to be turned on to be affected.

Before assuming you have the conundrum, try replacing the cables, and testing other firewire devices with the computer to make sure the Firewire port on the computer isn't broke and to make sure the cable isn't broke. Also test devices one at a time, instead of being daisy chained. If you have another Firewire case which you know isn't affected, or a PowerMac you can test the drive in, you can also isolate the problems to the Firewire port on the case having the problems. Inside almost every Firewire case is an IDE hard drive which will fit in any post-beige PowerMac G3 or G4. Since the conundrum causes the drive to become totally unreadable, finding that the drive is readable in another case says that the original case has a hardware problem and needs to be repaired or replaced. In addition, check Apple's article on what to do if you can't see a firewire device.

Another problem which may affect you is having two large data flowing devices on the same bus at the same time. I found with my own machine that it would freeze after trying to capture a large amount of video in one Firewire port to an external hard drive. A video export told me that if they are on the same bus that doesn't work well. To tell if your firewire ports are on the same bus, check the System Profiler utility's Firewire section.

There is a similar conundrum in symptoms that affects 10.3.3 through 10.3.6 (10.3.7 through 10.3.9 may or may not be affected by this problem), where the software update version of those updates doesn't fully install all Firewire drivers, and you need to apply the combined (combo) update or replaced the kernel extensions relevant to Firewire. Some drives also may not be readable if they are missing a jumper on their pins. Make sure you follow the manufacturer specification for where to put the jumpers for a master setting if putting the drive in a firewire hard drive case.

In some cases the directory of the drive may be damaged and needs to be fixed. If a directory utility mentioned in the link the previous sentence can see the drive, then that's probably all that needs to be fixed.

If you are unsure about having an affected drive and have made sure the above troubleshooting steps do not apply, it is recommended that you dismount the drive before doing any shut down, restart or sleep, and disconnect the cable to the computer or drive that allows for the Firewire connection after dismounting the drive. Do not connect the drive until after startup has finished and you can see the desktop.

To dismount the drive, drag its icon to the trash in the Dock, or if you have the sidebar open, click on the triangle to its right in the sidebar to make it disappear. This means you can't boot off a Firewire hard drive affected by this issue as it would require the drive be connected during startup and shutdown. Only reconnect the drive after the machine has successfully started up and shows the desktop and menubar. Also note, if the power should go off on the computer due to an brownout or outage, be sure to disconnect the Firewire cable from the drive to prevent it from automatically mounting when the computer restarts after power is restored. This last precaution is only necessary if Apple Menu -> System Preferences -> Energy Saver -> automatically restart after power failure is checked, though you should disconnect the firewire cable prior to restarting your computer once power has been restored if that option is unchecked.

If a firmware update is not available for your drive case, you can assume that it is susceptible to the conundrum in question, and you have to go through the procedure above of dismounting and disconnecting prior to shutdown, restart, sleep, and remounting after successful boot. The one exception is drives that do not have an Oxford chipset.

Only Prosoft Data Rescue is known to be able to rescue data off of affected drives. The best chance at success of rescuing data is having a supported drive to copy the rescued data over to, and not having run any disk directory repair utilities before attempting the rescue.

It is recommended you do not erase and install Mac OS X 10.3, due to the severity of this conundrum, and instead:
Archive and Install Mac OS X. Especially do this if you can't afford a second backup. The reasoning for this is due to the fact that once you erase your original hard drive, your backup becomes your one and only original. People have been known to assume that drive was safe, and then were hit by the conundrum and found they could no longer read their backup when trying to recover from the backup. Only an Archive and Install will make sure that both your user data and applications get preserved while giving you the option to disable user or system level preferences to find out if one of those is corrupt.

Apple's Important Note

The Important Note on 10.3.1, 10.3.2, 10.3.3, (10.3.4 is conspicuously missing a note), 10.3.5 10.3.6, and 10.3.9 update pages say it is only partially resolved:
Apple has identified an issue with external FireWire hard drives using the Oxford 922 bridge chip-set with firmware version 1.02 that can result in the loss of data stored on the disk drive. Even with the improvements available in this update, Apple recommends you update the firmware on your FireWire drive. Please contact your drive manufacturer for more information.

Strangely missing from this note is Oxford 911's status even though many people reported identical symptoms to the conundrum with Oxford 911 drives. And as you'll see below, MacAlly has gone as far as to assume the conundrum exists for Oxford 911, and provided a firmware update which makes their drive cases safe.

Manufacturers with at least partial if not complete immunity from the conundrum

Links to the vast majority of the below have been relocated or are gone. I am no longer monitoring where those links are. The vendors whose website mention either a firmware update, or are using a non-Oxford chipset are linked to below, and at least some of their drives are safe from the conundrum:

Acomdata*, Bytecc*, Century Global, Cooldrives*, EZ Quest, Fantom*, Firewire Depot*, Firewire Direct, Genesys Logic (see also MacPower note about Genesys 711), Glyph, LaCie, MacAlly*, Mad Dog has no support for 10.4.11, MacPower, Mapower, Maxtor, Otherworld Computing, Prolific*, Que-QPS, SmartDisk, Trans Intl, Western Digital*, Wiebetech, Make sure to check their website to find out which drives are not affected by the conundrum. Asterisks indicate some known exceptions.

Manufacturers whose drives are not known to be safe from the conundrum

The manufacturers as of this writing who have no firmware update or addressing of the Firewire conundrums that I am aware of are. Their links are given so that you may contact them to find out the status of their drives:

Note this listing is only an encouragement for you to ask your drive manufacturer to find out if they could put on their website the status of their addressing the conundrum. It should not be used as a discouragement from buying those drives, and you should contact them to ask them to make their stance on the conundrum more clear on the website. Until then, there are these tips for avoiding the conundrum which were mentioned earlier.
If you know you have one of these drive manufacturers firewire drives, and can find a firmware update for their drive that says it helps stop the Firewire conundrum of 10.3 or some listing saying they use the Initio chipset, please sign the guestbook with where that information is posted on the web. Also please sign if you know of another manufacturer whose driver status is uncertain, or chip manufacturing is uncertain. And if you know a specific model number of one of the above manufacturers's drives works with Mac OS X 10.3 through a restart and power on with the drive, please add that to my guestbook so that it may be added to this website for others to know. Please also specify which version of X you tested it with.

If you find other drives are not compatible, please post feedback to the drive manufacturer, Oxford Semiconductor (now owned by Broadcom and at one point Plxtech), and Apple's Mac OS X feedback page with the information about the speed of the Firewire, bridge info if you have it, and maker and model of the drive in question.


* Acomdata uses the Initio chipset on some of their drives, and those are not unaffected by the conundrum through 10.3.5. Other drives of their's are Oxford. To find out which one your drive has, contact Acomdata and give them your drive's model number. 10.3.6 through 10.3.9 may be a different story.

Bytecc driver only exists for the ME 350

Cooldrives firmware updates are now in the Cooldrives link above including both Oxford 911 and Inito 2430 firmware. Note
some drives may already have a newer 2.1.8 firmware for Initio, while 2.1.6 is what is available on the website. The updater
will warn you if that is the case. My two Cooldrives do not appear to be affected by the conundrum with 10.3.6 through 10.3.9, though others may be.

Fantom - One user reports that their model#TFDF12072 Fantom drive had no trouble with 10.3.7. Fantom has no direct plans to update their drives for Mac OS X according to that user. If you find you are having similar issues to those which are related to this FAQ0 please contact them.
Firewire Depot refers to the document about the conundrum on the Oxford 922 website from Oxford, though does not appear to have the actual download to install the firmware update even though they have Oxford 922 chipsets in their drives. E-mail them to ask if your particular model has already had the firmware update applied.

Genesys Logic - maker of some Firewire bridges in some generic hard drives is known to have at least this bridge as running safely through 10.3.9 on updates and restart:
Speed:400 Mb/sec Speed
Unit Spec Id:24734
Firmware Revision:0.01
Unit Software Version:10483
as reported by a reader's Apple System Profiler.

Granite Digital uses the Initio bridgeset which is different from Oxford on their Firewire cases, and is unaffected by the conundrum.

Initio as of November 9, 2004, had provided an update which addresses 10.3.6 through 10.3.9 Firewire issues. Initio does not make Firewire hard drive cases, instead it provides the chipset that is in many of them much like Oxford and Part 2. In addition, its readme illuminated potential reasons for the other Firewire conundrums seen on this page:

Apple made a change in their Mac OS 10.3.6 FireWire driver and now requests a very big packet and when we try and send a large packet back it won't accept it so Apple keeps re-trying until Apple timeouts. Sometimes after a few minutes and Apple timing out, the hard drive will then appear on the Mac OS desktop, but not always, depending on what previous Initio firmware is on the FireWire 400 bridge you have. So what we did is break up the larger packet into smaller packets so Apple can accept it. You won't be able to flash update on 10.3.6, so you will have to do it on an earlier Mac OS version or on a PC because we need a mounted volume to flash update.

If you suspect the reason for your issue is this problem, please contact your drive manufacturer and tell them of Initio's Update if you aren't able to use it on their drive case. This may also require contacting Part 2 research or Oxford Semiconductor (now owned by Broadcom and at one point Plxtech) depending on your finding out which chipset the drive case manufacturer uses on your drive model number. But the important thing is that the packet size that Apple is using on 10.3.6 through 10.3.9 is found out by all three major IDE to Firewire bridge chip vendors, and if there are any other vendors, please let me know in my sign guestbook that I may add that to this list.

MacAlly now provides a firmware update for Firewire 400 drives using the Oxford 911 chipset, though it is unknown if it is firmware update can be used on other Oxford 911 drives.
MacAlly ECO 350Ua Firewire/USB enclosure is known to work with 10.4.11 according to one reader.
Note, the new MacAlly PHR-100AF using an Initio chipset, and Macally PHR-100AC using a Part 2 research appear to not be Mac OS X 10.3.6 through 10.3.9 compatible.
MacAlly has been made aware of the problem, though can use help finding out what exactly is happening.

Macpower - A reader reports:
I know some "Macpower" drive cases -- those sold by that use a chipset called
"Genesys Logic 711" -- are unsafe with OSX 10.3. Meritline last November [reader report from January 2005] added the big red flag warning
on their web page (although Meritline hasn't replied to inquiries; Macpower hasn't replied to inquiries
and their web page has been missing; and Genesys hasn't replied to inquiries and their web page is
unresponsive when I've checked. Genesys Logic did advertise the "711" firewire chip as being flash-updatable,
but apparently doesn't actually provide an update path for it.
Please sign guestbook if you have further news about updates which may related to this reader's remarks.

Mad Dog - Reader reports that Mad Dog (note link was closest I could find to hard drives made by Mad Dog, if this is a different company, please correct me via my guestbook link) Model No was MD-EN-350COM enclosures no longer work as of 10.4.11. Please sign guestbook if you have further news about updates which may related to this reader's remarks.

Mapower's - 1.1 update for 10.3 on the link above addresses the Oxford 922 conundrum for 10.3 to 10.3.5. However, at this time it is unknown if it addresses the 10.3.6 through 10.3.9 conundrum or other bridgesets for their drives.

Maxtor - two models are reported to be compatible thus far: FWRA060RGL. Maxtor's one touch 250 has new drivers on Maxtor's website that make it Tiger compatible. In addition, the link to where they recognize Apple's recognition of the conundrum is also given above, though it assumes that Oxford 911 is safe. As has already been discussed in this FAQ, Oxford 911 is not 100% safe. The 5000XT 250 GB model is was reported by a reader of this website as compatible with 10.3.6. The Maxtor one touch storage and backup combo interface USB2.0 & FireWire KIT: A01A250 was also reported to be bootable and free of the conundrum. Be sure to sign the guestbook if you know of other drives that are compatible.

Prolific PL3507 - had shown trouble with earlier firmware versions on Mac OS X 10.4.

Que-QPS - The model QPS Que! M3 60GB FW400 is known to work fine with 10.2.6 through 10.3.5 without the conundrum. The QPS Que!M3 60 GB 7200 RPM FireWire Model # QPS 525 is also known to work through a restart in 10.3 to 10.3.5 while turned on, however is NOT able to be booted from. No other firewire hard drive model at this time is known to work well from Que. Please sign the guestbook if you find others.

Smart Disk claims they don't use the chips that are affected by the conundrum.

Western Digital claims that all current drives use the Initio chipset for Firewire and are thus unaffected by the conundrum through 10.3.5. 10.3.6 through 10.3.9 may be a different story. The WD1200B002 was reported by a reader of this website to be compatible with 10.3.6.

To find out which type of chip your drive came with, use the link above to send e-mail to the tech support with your model number of the hard drive. Western Digital provided a firmware for 10.5.2 and some of their drives.

For more on the Firewire conundrum and various tips people have discovered, visit Macintouch's Firewire coverage

Please sign guestbook if you have any further relevant information. Return to homepage