Our reports on FireWire hard drive problems with Panther continue today with updated announcements from Apple, additional statements and firmware updates from drive vendors, comments and information from LaCie, and some more MacFixIt recommendations.
Apple updates official statement Yesterday Apple updated their official statement on Panther/FireWire issues. It still maintains that the "identified" issue involves "external FireWire hard drives using the Oxford 922 bridge chip-set with firmware version 1.02." However, the statement now includes the following paragraph:
"Update 11/4/2003: Apple and Oxford Semiconductor have confirmed that firmware version 1.05 resolves the data loss issue experienced by some FW800 users. FireWire disk drive manufacturers have begun posting firmware updates. [list of updaters below] Only use the updater provided by the maker of your drive and follow the installation instructions carefully. If your drive manufacturer is not listed, contact them for more information."
List of manufacturers providing firmware updates As part of the above web page, Apple has listed the following drive manufacturers as those who have provided firmware updates for affected drives:
- Century Global
Club Mac Ezquest
Other World Computing
FireWire Depot providing firmware update for Initio 2430 chipset Although Apple claims that the Panther/FireWire issue only affects Oxford 922 chipsets, we received an email from FireWire Depot that includes the following statement:
"While all of the problem reports have focused on the Oxford 922 chip, some users are experiencing some problems with other chips sets as well and the Initio 2430 utility can be used on the new Initio 2430 1394b chip."
FireWire depot has posted both firmware update utilities -- one for Oxford 922 chipsets, one for the Initio 2430 -- on their home page.
Comments and information from LaCie On Wednesday, we spoke with LaCie representative Mike Mihalik about this issue. LaCie's drives are among those affected by Apple's "official" bug (Panther/FireWire 800/Oxford 922 chipset), and LaCie was among the first vendors to provide a firmware upgrade for those drives. During our conversation, Mike provided a good deal of helpful and interesting information about the current FireWire issues. (If you'd like to send comments or questions to LaCie about their drives, or about the info below, email them at email@example.com.)
- FireWire 800 vs. FireWire 400 drives We have previously expressed concerns, based on numerous reports of problems with FireWire 400 drives and Panther, that this issue may not be restricted to FireWire 800/Oxford 922 drives (or, at the very least, that a different issue is affecting some FireWire 400 drives). We also reported on a claim by Oxford Semiconductor that it would be "impossible" for this official bug to affect Oxford 911 chipsets. LaCie confirms Oxford's position, stating that the circumstances and technical details surrounding the bug that Apple has acknowledged relate to specific ways in which FireWire 800/Oxford 922 drives communicate with the operating system. In other words, since FireWire 400 drives, and drives using the Oxford 911 chipset, don't communicate with connected computers in exactly the same manner as FireWire 800/Oxford 922 drives, this particular bug cannot affect them.
This does not rule out the possibility that there may be issues affecting other drives. However, it means that if other drives are indeed having problems with Panther, they are having problems for different reasons.
- Technical background Whenever a drive is used by a computer, it communicates its current state (reading, writing, sleeping, etc.) to the computer, and the computer likewise communicates with the drive (telling it to read or write data, spin down, eject, etc.). Evidently, when this bug strikes, it is caused by the communication timing between the drive and the computer, particularly when the operating system tells the drive to "eject." The drive executes its unmount/eject procedure, but the OS may not be "listening" when the drive reports its status. The result is a miscommunication that results in incorrect data being written to the drive.
In terms of what is happening to the drive itself, it appears as though the blocks at the beginning of the drive are being overwritten by a string of zeros. This can have a number of effects. First, if your drive is fairly new and/or larger, the volume directory will often be contained in a contiguous span of blocks at the beginning of the drive, and most files will be stored contiguously elsewhere. In this scenario, the overwriting of zeros at the beginning of the drive means the directory will be lost, but your data may be untouched. This is why many users are having success using Prosoft's Data Rescue X to recover their data, as covered in yesterday's report. On the other hand, when a drive is smaller and well used, files, folders, and directory information are fragmented across the drive. In these situations, only part of the drive directory will be damaged, but you may find that portions of your data are also unrecoverable. Finally, if you've ever partitioned your drive, the drive's partition map is also located at the beginning of the drive, so it will most likely be destroyed, meaning that the drive will no longer appear to be partitioned. However, there is an upside to this situation: since both the data and the volume directories for partitions besides for the first one are stored away from the beginning of the drive, they should remain intact, so utilities like Data Rescue may actually be more successful in recovering data off of those partitions than if the drive consisted of a single partition.
One interesting note: we have previously discussed the FireWire 400 drive lost by a MacFixIt editor, which was eventually sent to DriveSavers for successful data recovery. Since DriveSavers returns drives in exactly the state in which they received them -- they recover data to other media and return the bad drive untouched -- we installed the drive in a Mac running OS 9 and ran Sedit, a block-level drive editor, to view the drive's blocks. We found that the beginning of the drive had been overwritten with zeros.
- Why different drives behave differently One thing that is clear about FireWire drive problems is that not everyone is affected, and when people are affected, they aren't necessarily affected in the exact same way. For example, just because a particular drive uses the Oxford 922 chipset doesn't mean it will fall victim to (or avoid) the same problem as another drive using the same chipset. The reason for this is that the chipset is just part of the drive's FireWire interface. The entire interface consists of the bridge design (which converts the connection type provided by the drive -- IDE, for example -- to FireWire), the FireWire chipset itself, and the firmware currently in use by the chipset. Different vendors use different combinations of bridge design, chipset, and firmware, so without knowing each particular part of this interface, there's no way to predict how a drive will react to potential FireWire issues. In fact, even two drives using the same chipset and chipset firmware might behave differently, because the hardware itself may be slightly different. (This also makes testing for such issues fairly difficult because of the myriad combinations that are possible.)
On the other hand, because LaCie knows the specific interface combinations used in all their drives, and they also know exactly what sequences of commands are causing this issue, they are confident in saying that their FireWire 400 drives, and their FireWire 800 drives that have been updated using the firmware updaters they have provided, cannot be affected by this issue.
- Using firmware updates on unsupported drives A number of MacFixIt readers have reported success in using a firmware updater from LaCie or another vendor to update the firmware on a drive not manufactured by that vendor. Mike warned against taking this action, for the same reasons that drives often behave differently: there's no guarantee that the two drives have the same bridge/chipset/design combination, so you have no way of knowing if the firmware updater will fix the problem, make it worse, or possibly even damage the drive. For example, when LaCie provides a firmware updater, that updater is written for, and tested on, LaCie drives only. Using it on other vendor's drives may provide unexpected results. (In fact, the most recent LaCie firmware updaters will only work on LaCie drives, in order to prevent such potential problems.)
- In-house experiences Interestingly enough, LaCie engineers haven't had a single failure while testing drives for this bug under normal circumstances, even when testing the specific combination of factors that have been implicated by Apple. They know exactly what sequence of commands triggers the failure, and have been able to "fail" a drive by issuing those commands via special drive-level instructions, but they haven't actually had a drive fail during normal use. This further supports the assertion that although the issue has been isolated, it's not necessarily repeatable or guaranteed to occur.
We want to thank Mike for taking the time to speak with us; we're sure MacFixIt readers will find this information both interesting and useful.
Old QPS statement As an interesting side note related to an issue we brought up yesterday -- that users have reported problems with OS X and FireWire drives for some time -- MacFixIt reader Richard Bastiaans directed us to a two-year-old statement on the QPS site regarding the use of Que FireWire hard drives with OS X:
Can I use my QUE firewire hard drive drive on OS X?
We do not yet support these drives on OS X because there are still some communication issues with the operating system. However, many of our customers are using the drive without problems on OS 10.1.3. If you are going to use the drive on 10.1.3, then format the drive using the disc utility in OS X.
MacFixIt Recommendations We've previously provided a few recommendations for dealing with, and avoiding, these issues until we can conclude it's "safe" to use FireWire drives normally. Below is a summary of those recommendations.
Recovery discounts As a reminder, both Prosoft and DriveSavers have offered MacFixIt readers discounts on their products and services. Prosoft is offering $10 off of the purchase of Data Rescue X by ordering directly from Prosoft and entering coupon code PAN911 at checkout. DriveSavers is offering a 20% discount on their data recovery services for those users who have been affected by these Panther/FireWire issues.
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