DH0: NDOS - argghh! can I recover/repair?

[gizmomelb]

Hi all,

I've just booted my A1200 this morning and the DH0: partition of my HDD says it is an NDOS partition.  I'm running Quarterback tools to try to repair it, but QBT can only see my DH1: partition.

Can anyone please help me with advice on how to repair the DH0: partition?

Please?!!?

[a1200]

Could try quick formatting it and using QuarterBack or DiskSalv to either undelete or unformat.

[gizmomelb]

thanks for the advice - after playing around a bit with QBT6 I noticed that it supported drives or devices, so I switched to devices and was able to repair the bootblock of DH0: and get the system working again.

However my DH1: partition is having some problems - it's 90% full (or so workbench claims) but it does have a hell of a lot of files on there, I'm wondering if the FastFileSystem is similar to the IBM File Access Table (FAT) where if you have a lot of files on a drive, the drive can report free space but actually be totally full?  (sorry for the bad description).

Anyways, I've moved some files from DH1: to DH0:, which has more free space.  So hopefully I won't have the file corruption again.

[Thomas]

How big is the drive ? If it is bigger than 4GB then you obviously don't have the correct drivers installed.

Please run Check4GB from Aminet and post the output here.

Bye,
Thomas

[Noster]

Hi,

> However my DH1: partition is having some problems - it's 90% full (or so workbench claims)
> but it does have a hell of a lot of files on there, I'm wondering if the FastFileSystem
> is similar to the IBM File Access Table (FAT) where if you have a lot of files on a drive,
> the drive can report free space but actually be totally full?

No, the FastFileSystem doesn't use a FAT, it allocates blocks for files or directory entries as required until the disk is 100% full.
Every file uses at least a whole block of the disk. If you have formated the drive with larger blocksizes (e.g. 2048 bytes) even a file of only a few bytes will use 2KB diskspace. So your drive could be full even if the summary of the filesizes isn't as large as the partitionsize.

Noster

[gizmomelb]

Thanks Noster,

that was exactly what I was trying to say, just not as elegantly or technically correct

[CDE_MusiX]

but FFS and FAT are 2 diverse File Systems? i guess are all 16 -bit work and the FAT support hard disk for 2GB max. And, if i use an internal 2.5 IBM Notebook preformatted hard drive, how to prepare and format for use with workbench?

[Noster]

Hi,

FFS is a 32 bit filesystem -- as any Amiga-software is 32 bit software. It is able to address 2^32 blocks. If you format the drive with a block-size of 1024 bytes (1KB) FFS could handle disks upto 4 terabyte.
The problem is not the filesystem, it is the exec-device that could only handle disks upto 4 GB in AmigaOS 3.1 or below. There is a patch available for the trackdisk.device that uses 64 bit addresses called TD64. But the easiest way is using AmigaOS 3.5 or 3.9 with that large drives.

Your 2.5 GB drive should be usable with OS 2.0 or newer without any additional patches. The size of the drive would be displayed as negative value but nevertheless the disk is handled correct and can be partioned using the HDToolBox.
I would at least use two partitions, one for the OS and another one for private data so you could avoid any problems with partitions larger than 2 GB.

Noster

[PaSha]

CDE_MusiX wrote:
but FFS and FAT are 2 diverse File Systems? i guess are all 16 -bit work and the FAT support hard disk for 2GB max. And, if i use an internal 2.5 IBM Notebook preformatted hard drive, how to prepare and format for use with workbench?

No, FFS is 32-bit, as mentioned above.
(edited due to incorrect mathematics....)

FAT16, the old MS file system, was 16-bit, hence only able to adress 65536 sectors. With the max sector size of 32768B (!) it maxed out on 2 GB, and wasted lots of space, because no matter how small the file was, it occupied 32kB of space on the HD.

-Paul

[Hyperspeed]

This sort of weird thing can also happen if you mix the use of HDToolBox with HDPrep or SCSIConfig.

They all write their own type of RDB to the drive and things can overlap with unpredictable consequences. If something turns on the following day differently though it's worth checking if the drive has bad sectors, if you switched off during a write or if (like me) you get trouble with your interface - particularly SCSI issues.

DiskSalv is a lifesaver but it's always important to either back up your RDB or write down the block limits etc. of each partition so things can be recovered should the RDB be corrupted.

I remember overwriting the RDB but for some reason I had written down the size of each of my partitions and by sheer luck managed to retrieve lost files by re-partitioning the drive, quick-formatting and then using DiskSalv to 'Salvage' the data that always remains on a drive (until it is given a FULL Format).

Keep magnets, amplifiers and unshielded speakers away from your Amiga too!


:-)

[gizmomelb]

CDE_MusiX wrote:
but FFS and FAT are 2 diverse File Systems? i guess are all 16 -bit work and the FAT support hard disk for 2GB max. And, if i use an internal 2.5 IBM Notebook preformatted hard drive, how to prepare and format for use with workbench?

Hmm, I just realised that this might be my problem with partitions being constantly trashed..  I have a 4.6GB laptop HDD installed in my A1200 and I'm using WB 3.1 and FastFileSystem (no patches or anything).

IDH0: and IDH1: are both around 2.3GB in size.

If I re-parition and make each partition around 1.5GB in size - would that solve my problem (I'm unsure if the problem is the partition is >2GB, or the HDD is >4GB).

Should I be running another FileSystem or some patch or something please?  I just want my HDD to stop corrupting!  (I know it's not the drive, I've tested the drive in an IBM using the drivecheck program and there's no bad sectors/blocks/whatever).

Thanks,
Gizmomelb

[zipper]

To be safe make just 2 x 1.99 GB partitions and leave the rest unused. Or get updated driver/OS etc. You are lucky if you somehow could use 4.6 GB unpatched - every write attempt over 4 GB wrapped back to somewhere most probably into your IDH0: corrupting it.

[gizmomelb]

Many thanks!

That explains everything!

[Oliver]

Quick note on speakers: most 'shielded' speakers do not actually shield magnetic 'near fields' very well.  This is particularly so for sub-woofers.  Near field affects of magnetic fields are actually rather difficult/expensive to deal with, and generally most designers just use spacial isolation rather than shielding to eleviate detriment to other systems.  My brother completely destroyed one computer from running it next to his sub-woofer under his desk.  I know this is not the problem here, but just thought I would mention it as it came up in discussion.

[CDE_MusiX]

hmm, on workbench is available a tool to partiton hard drives with custom capacity?
And, if while formatting partitions i find bad sectors?!?   :-(