compact flash question

[AAACHIPSET]

just curious ..thinking of getting a larger compact flash card ..used 2  4gig cards for 2 different  type setups  ...can i use larger than 4gig ?? ..would like to use a 8  or  16 or even 32  gig compact flash card  ..probably partioned  in 2 or 4 gig partions ....anyone  done this ..?

[Thomas]

For CF cards the same limits apply as for hard disks. 4 GB is an OS limit. You need to install updated drivers to use larger drives. The boot partition always has to be inside the first 4GB. Sizes up to 2 TB are possible with the right drivers and a matching file system.

Up to 8 GB is possible with a new file system only (no driver patches needed and no limit for the boot partition). For example these:
http://aminet.net/package/disk/misc/ffstd64
http://aminet.net/package/disk/misc/PFS3_53

(Some CF cards report CHS values which are higher than allowed by the specs. With these special cards even more than 8GB is possible.)

[fishy_fiz]

Yep, I use a 32gig CF card in my a1200.
Other than that there's nothing to add to Thomas' response. As far as the Amiga is concerned the CF card is no different to a harddrive.

[paul1981]

I would just like to add that make sure you do indeed create two partitions if you're using a CF/HDD larger than 8GB (unless you have a custom kickstart ROM chip with latest scsi.device). And of course, use PFS3 or SFS.

[Thomas]

I would just like to add that make sure you do indeed create two partitions if you're using a CF/HDD larger than 8GB (unless you have a custom kickstart ROM chip with latest scsi.device). And of course, use PFS3 or SFS.

Yes, that's true generally. But as mentioned above, there are a few (probably cheap) CF cards which report their real size through CHS although this is not allowed by the ATA specs. With these CF cards you can have one large partition as long as the file system supports Direct-SCSI (which rules out SFS but qualifies FFS V44).

[paul1981]

Yes, that's true generally. But as mentioned above, there are a few (probably cheap) CF cards which report their real size through CHS although this is not allowed by the ATA specs. With these CF cards you can have one large partition as long as the file system supports Direct-SCSI (which rules out SFS but qualifies FFS V44).

If a user has one single bootable partition of capacity greater than 8GB, and he or she has standard 2/3/3.1 roms, then if the Startup-sequence is edited when the disk data is beyond the 8GB barrier (standard old scsi.device limit) then the Startup-sequence will be rendered unreadable by the system. :nervous:

[danbeaver]

Mech, of A4000T.com fame says that 64GB is about where the Amiga functions at its top limit of CF cards. The Amiga firmware has a boot partition limit to 4 GB and many programs (ReOrg, DiskSalv, etc.) use this limit as well. Once booted the HDD limit I had was 2TB, that is the largest HDD I had to test (one of five 2TB HDDs in my PC -- DVR'd movies). This was seen in OS 4.1 and 3.9.

On the Amiga, I believe if one needs a larger boot partition, one may wish to reconsider WTF it is being used for. Only my biased opinion though.

[Thomas]

If a user has one single bootable partition of capacity greater than 8GB, and he or she has standard 2/3/3.1 roms, then if the Startup-sequence is edited when the disk data is beyond the 8GB barrier (standard old scsi.device limit) then the Startup-sequence will be rendered unreadable by the system. :nervous:

Why should this be? Don't you read what I write? If you use a file system which uses direct-scsi commands, you can use all capacity the scsi.device recognises as one partition. If you don't have such a file system, all partitions (not only the boot partition) are limited to the first 4 GB of the drive. File corruption only happens in the latter case, if you don't limit partitions to the first 4GB of the drive.

File systems with direct-scsi capability include the old SFS V1.84, FFS V44 (which is the result of the FFSTD64 patch), PFS3 DS and PFS3 AIO.

There is no 8GB limit as such, but scsi.device limits the capacity to what the drive reports. I the drive reports its size according to the ATA specs, the capacity is limited to 8GB. But if the drive does not follow the ATA specs and reports its real size, scsi.device can use all the capacity with direct-scsi commands.

Only if you want to patch scsi.device and then use a file system which does not use direct-scsi but TD64 or NSD, then you need to arrange the boot partition inside the first 4GB and can have other partitions outside.

Another problem can arise if you use FFS (V43 or higher) with big partitions but don't have enough RAM to allow the disk-validator to validate the partitions. Then the affected partition will remain full and write protected although there are no files on it.

[AAACHIPSET]

just curious ..thinking of getting a larger compact flash card ..used 2  4gig cards for 2 different  type setups  ...can i use larger than 4gig ?? ..would like to use a 8  or  16 or even 32  gig compact flash card  ..probably partioned  in 2 or 4 gig partions ....anyone  done this ..?

just a quick question sorta  followin on from the compact flash  ..i use a 2 gig an a 16gig usb  flash drive  ..the 16 gig  is not partioned just 16gig ..i dont boot from it ..it just holds files to transfer from pc to amiga an back ..the amiga sees all 16 gig ..so if i added  a larger drive usb  powered  ..say 1 terabyte ..would the amiga see it all ? or is usb different ..like scsi seems to be  ..?

[Thomas]

The next limit above 4GB is 2TB. The limits shown above only apply to the internal IDE controller of the A1200/A600/A4000. (The IDE driver is called scsi.device for compatibility, other than that there was no mentioning of SCSI yet. Direct-SCSI is a software interface. The IDE driver also interpretes these commands, it's not necessary to have SCSI hardware for this.)

But there are also file system limits. PFS3 has a limit of 100 GB, SFS has a limit of 128 GB for a partition.

[paul1981]

Why should this be? Don't you read what I write? If you use a file system which uses direct-scsi commands, you can use all capacity the scsi.device recognises as one partition. If you don't have such a file system, all partitions (not only the boot partition) are limited to the first 4 GB of the drive. File corruption only happens in the latter case, if you don't limit partitions to the first 4GB of the drive.

File systems with direct-scsi capability include the old SFS V1.84, FFS V44 (which is the result of the FFSTD64 patch), PFS3 DS and PFS3 AIO.

There is no 8GB limit as such, but scsi.device limits the capacity to what the drive reports. I the drive reports its size according to the ATA specs, the capacity is limited to 8GB. But if the drive does not follow the ATA specs and reports its real size, scsi.device can use all the capacity with direct-scsi commands.

Only if you want to patch scsi.device and then use a file system which does not use direct-scsi but TD64 or NSD, then you need to arrange the boot partition inside the first 4GB and can have other partitions outside.

Another problem can arise if you use FFS (V43 or higher) with big partitions but don't have enough RAM to allow the disk-validator to validate the partitions. Then the affected partition will remain full and write protected although there are no files on it.

I used the Startup-sequence for the "best" example. With the standard Kickstart 3.0/3.1 v40 scsi.device (which is all that's available from a cold boot) no drives of capacity above 8GB can be utilised fully (ie to use their whole capacity) beyond 8GB (even with PFS3DS). That's my experience with my A1200 at least, maybe it's different with CF HDD's, but I don't use CF HDD's.
So the user must then either load a custom Kickstart containing an updated scsi.device (ie v43.x) or load the updated scsi.device as a resident module. The commands that achieve this reside in the Startup-sequence.
Now, if a user has a hard drive that's 40GB for example, and there's just one single large partition (ie, the boot partition 40GB), then as soon as the data writes to the drive reach beyond 8GB then any such writes past that point on the disk will not be readable by the v40 scsi.device. PFS3DS actually locks the drive (I've tried it!).
From cold boot, all we have is the v40 scsi.device - so any modifications to the Startup-sequence or other boot files will not be readable by the Amiga upon cold boot due to the data (Startup-sequence in this case) now being beyond the 8GB point. So basically, the module for loading the essential v43 scsi.device will not be able to load at cold boot due to the Startup-sequence being unreadable. The user then has a serious problem.

Under PFS3, the filenames of such files will be intact due to it's metadata being stored at the beginning of the drive, but file content unreadable under scsi.device v40.
Solution is as my previous post (assuming PFS3DS and internal IDE). If using a boot drive above 8GB, make sure to create a minimum of two partitions, the bootable one must exist within the first 4GB of the drive but can be as large as 8GB in size only (to avoid such problems like I'm trying to describe above).
Or, burn a custom Kickstart ROM with scsi.device v43 or higher.
Of course, if the drive isn't going to be booted from then yes, you can safely create a single large partition of any capacity.

[Thomas]

All you say is true for all drives but a few. Those few drives do illegal things with the response to a capacity query and thus allow scsi.device to access the entire drive and not just the first 8 GB as it should be.

There is the explanation: http://eab.abime.net/showthread.php?p=846925#post846925

So a lucky guy might be able to use a 32 GB CF card with just a Direct-SCSI file system and no scsi.device patch. Bad luck for you that you never saw such a drive.