limiting hard drive size

[scottwmlewis]

I'm working with an embedded controller that is using some flavor of Linux or at least an OS using the ext2 file format. That HDD is failing and I need to replace it with another one. The problem I'm having is the 20gb drive I'm using as a replacement for the original 10gb drive isn't working.

I've been able to spend very little time with the issue so far. I hope to be able to take a real close look at it this weekend. I have two possible causes in mind, some 'stuff' laid down on the mbr to make it difficult to use a non-vendor provided drive or something to cause the drive to look like a 10gb drive. The original HDD is actually the identical drive that I'm replacing it with except that it looks like a smaller drive that it actually is.

Does anyone have any ideas about how a 20gb drive can end up looking like a 10gb drive? The original drive from the vendor is a Toshiba 20gb drive that looks like a 10 gb drive under windows and DOS with various utilities including Partition Magic.

I've tried manually creating all of the partitions identical to the original HDD. When I load the vendor's provided software using their boot/loader, it recreates the partitions. They are all identical to the original hdd, except the last partition is 10gb larger. And, at this point it fails to proceed. I can put the old drive back in and repeat the procedure and it works.

Anyway, hdd too big, keys/locks in the mbr or something else?

Thanks for any insights here.
Scott

[Richard_The_Lionhearted]

Well I think I can see the problem. You created all the partitions like the original, which was 10 gb. You added a 20 gb hard drive and you only ended up partitioning half of the drive(10gb). Simple fix this by adding more space to the partitions.

[scottwmlewis]

Well I think I can see the problem. You created all the partitions like the original, which was 10 gb. You added a 20 gb hard drive and you only ended up partitioning half of the drive(10gb). Simple fix this by adding more space to the partitions.

I've tried this a couple of different ways. When I run the the firmware update utility, it does the partitioning of the HDD overwriting any partitioning I put on the HDD. I tried manually partitioning the drive to match the partitioning of the original drive to no avail.

I've since been able to look at the two drives on my home system. When the motherboard BIOS detects the drives, they appear to be different sizes even though they are both identical models, toshiba MK2023GAS 20gig drives.

I have convinced myself that the original HDD has been 'programmed' to present itself as a 10gig drive either by the embedded controller vendor or as a special order by toshiba for the vendor. Perhaps there are other settings in the drive that are being checked that may also prevent a standard HDD from being used. I took a quick look at the programming manual for the drive...... at 139 pages it will take me more than a cursory look to figure out how this all works.

[Richard_The_Lionhearted]

The toshiba MK2023GAS 20gig is ideal for video recording and editing, it has a low power consumption and provides ideal storage for a range of commercial and consumer notebooks. It boasts a data transfer rate of 100MB per second, rotational speeds of 4200rpm and has an average access seek time of 12ms


Here are some specs


— 20GB capacity
— 9.5mm High
— 2.5" sized drive
— 12ms Average Seek Time
— ATA-2,3,4,5 Interface
— Supports high transfer rates of 100 MB/sec
— Rotational speed of 4,200rpm
— 2,048KB Buffer
— 300,000 MTTF Hours
— Fluid Dynamic Bearing (FDB) motor drive

Model Toshiba MK2023GAS (HDD2187)
Data Storage Physical Per drive, formatted: 20.003GB
Data Heads: 2
Number of Disks: 1
Logical Configuration Heads: 16
Cylinders: 16,383
User Sectors/Track at zone 0: 63
Logical Blocks (LBA): 39,070,080
Rotational Speed 4,200rpm
Data Transfer Rate Max transfer rate to host 100MB/sec
Seek Time Track-to-track: 2ms
Average: 12ms
Maximum: 22ms
Average Latency 7.14ms
Interface ATA-2/3/4/5
Buffer 2,048KB
Nominal Power Requirements Logic: +5V (±5%)
Start: 4.7watts
Seeking: 2.6watts
Reading/Writing: 2.3watts
Idle: 0.9watts
Standby: 0.25watts
Sleep: 0.1watts
Dimensions Height: 0.37" (9.5mm)
Width: 2.75" (69.85mm)
Depth: 3.94" (100mm)
Weight 3.316 oz (94g)
Ambient Temperature Operating: 41°F ~ 131°F (5°C ~ 55°C)
Non-Operating: -4°F ~ 140°F (-20°C ~ 60°C)
Shipping: -40°F ~ 158°F (-40°C ~ 70°C)
Vibration and Shock: Operating Vibration: 9.8 m/s2 (1.0G), 5 - 500 Hz
Operating Shock: 200g
Non-Operating Shock: 800g
MTTF (Power on hours) 300,000
Preventive Maintenance None
Error Rates: Non-recoverable: 1 in 10E13 bits
Seek: 1 in 10E6 seeks

Try to manually enter the information for the hard drive. It is possible that the bios is detecting less heads.

[retired1af]

I have convinced myself that the original HDD has been 'programmed' to present itself as a 10gig drive either by the embedded controller vendor or as a special order by toshiba for the vendor.

Could be something as simple as a setting in the BIOS itself. Have you gone into the advanced settings for the drive to determine this?

[scottwmlewis]

Just a reminder, the application that this HDD is going into is NOT a typical PC motherboard. It is going into a piece of hardware that may not even be x86 based.

I have no access to the 'bios' nor would I want to mess with it.

I have two HDD with the identical Toshiba model numbering. The reduced sized drive came from the vendor of the embedded controller.

Anyway, I'm still pretty much convinced the HDD controller 'bios' has been modified to present itself as a 10gb drive. I haven't come across any information about accessing the drive in any manner other than the normal data read, data write and bios handshaking by the mb at initialization. I did find a interface specification describing the various data formats most of which seems to have nothing to do with the normal ATA data read/write. I've swapped these two 'identical' drives back and forth on a couple of my PCs and they consistently show the normal 20gb and reduced size (10gb) sizes, respectively.

Looks like we are going to have to suck it up and put out the $500-$600 the vendor wants for a replacement 10gb HDD. (Notice there are no longer available 10gb Toshiba 2.5" drives, thus the 'reprogrammed' 20gb drive model.)