Amiga.org
Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: blakespot on August 24, 2014, 09:03:31 PM
-
Software or a hardware question? Hmm.
I have a 700MB SCSI HD on my GVP HD+8 SCSI controller in my A2000 w/ OS 3.1. I need to add a bigger disk. What is the max partition size under OS 3.1, ROM 3.1? Will a 40GB, 80GB, etc. disk work (even if nowhere near that space needed)?
Things to look out for? The Quantum drive I have is circa 1994. More modern drives present issues?
Thanks.
bp
-
Partition size limit is a software question.
But you are not asking for partition size limit but for harddrive size limit. Harddrive size limit is 4GB. You can connect a bigger drive if you use only the first 4GB of it. You can use more than 4GB with the right software.
Partitions must not be created outside the harddrive size limit. If you create a partition outside the first 4GB area (or crossing the boundary), writing to this partition will corrupt other partitions sooner or later. It's dangerous to deal with large harddrives.
-
Yes like thomas said it doesnt matter the interface (scsi) its os restriction
-
So I have this 7,200 RPM Seagate 4GB SCSI drive laying around.
SCSQuery tells me it has 6300 cylinders. It has 8 heads. How do I calc for HDToolBox Blocks / Track, Blocks / Cylinder to get a full 4GB? Interleave is 1.
I enter 6300 cylinders, but it changes nothing - I hear that #, tho it is in an editable field, is calculated by the other two values I mentioned.
Thanks.
Drive is a Seagate Barracuda ST34572WC.
bp
-
Click on Read Configuration, then the values should be right.
Size is calculated as Cylinders * Heads * Blocks per Track * 512
Blocks per Cyl is calculated as Heads * Blocks per Track.
There are only very rare cases where you have to edit the values.
-
I had it Read Configuration and while the vendor info is accurate, the physical attrib returned call it a 23MB drive. It is a 4GB drive. (Returns 1 head instead of 8, etc.)
bp
-
Please post all values as read by Read Configuration.
If the drive is 4119 MB, it will be shown as 23 MB because everything above 4GB (= 4096 MB) is cut off.
-
Please post all values as read by Read Configuration.
If the drive is 4119 MB, it will be shown as 23 MB because everything above 4GB (= 4096 MB) is cut off.
I will do so once I get back into town - out on vacation until Thurs evening. Thanks.
bp
-
Something I noticed. Here is a picture from the 'net of the same drive (same model #):
http://www.4drives.biz/images/DRIVEPICTURES/IBM_02K3404.jpg
It says 4.51GB USCSI. My drive says 4GB SCSI in the same place. I see more references to this model being 4.5GB than 4GB. I wonder why my drive is labelled as such? Two drives with same model # differing by .5GB seems odd.
My drive came in an SGI O2 and HDToolBox's Read Configuration reports both Seagate and SGI in the text details.
It seems I may have a 4.5xGB drive. Steps, then?
Thanks.
bp
-
There is a raw, unformatted size for a drive and after a format lays down the file system there is a much lower size; this is why the Amiga got 880K from a floppy DD, Apple got 800K, and IBM got 720K.
-
I think I had a similar one once; prepped it with P5 tools and was asked if the size should be restricted to 4 GB which I did.
-
There is a raw, unformatted size for a drive and after a format lays down the file system there is a much lower size; this is why the Amiga got 880K from a floppy DD, Apple got 800K, and IBM got 720K.
This does not apply to harddrives. They are formatted by the manufacturer and have a fixed number of sectors. All of these sectors are available to the operating system.
-
Something I noticed. Here is a picture from the 'net of the same drive (same model #):
http://www.4drives.biz/images/DRIVEPICTURES/IBM_02K3404.jpg
It says 4.51GB USCSI. My drive says 4GB SCSI in the same place. I see more references to this model being 4.5GB than 4GB. I wonder why my drive is labelled as such? Two drives with same model # differing by .5GB seems odd.
My drive came in an SGI O2 and HDToolBox's Read Configuration reports both Seagate and SGI in the text details.
It seems I may have a 4.5xGB drive. Steps, then?
Thanks.
bp
Please post all values as read by Read Configuration. Then I can tell you which values to use to restrict the drive to 4GB. IMHO there is no point to take the hassle with scsi driver patches and third-party file systems just for 0.5 GB.
-
This does not apply to harddrives. They are formatted by the manufacturer and have a fixed number of sectors. All of these sectors are available to the operating system.
So the low level format size of a hard drive determines the end capacity regardless of the type of file system, cluster size, ECC overhead, etc.?
-
"End capacity" might be lower. But your example does not mention end capacity. Your example shows low level format, number of sectors.
File system overhead is another story. For example an empty Amiga floppy formatted with OFS has 837 KB free, not 880K.
For harddrives the low level format is given by the manufacturer and cannot be changed by the operating system. If a harddrive is labelled as 4GB, it has ca. 8,000,000 sectors. This number is fixed for all operating systems.
File system overhead seldomly reduces the formatted capacity by more than 0.1 percent. OFS is a bad example. With FFS for example you get 879KB out of the formatted 880KB. File systems of other operating systems are similar.
-
So the type of file system, error correction, sector size, allocation size, file allocation table, all take essentially nothing away from raw storage capacity of the drive? Odd, I've never heard this before; tell me more.
-
Some good reading on the 4gb limits.
http://thomas-rapp.homepage.t-online.de/4gb_faq.html
http://thomas-rapp.homepage.t-online.de/filesyslimits.html
http://www.youngmonkey.ca/nose/articles/NewTekniques_9810/AmigaInMotion.html
-
So the type of file system, error correction, sector size, allocation size, file allocation table, all take essentially nothing away from raw storage capacity of the drive?
That's not what I said. They take their needed space when it is needed. But an empty partition is empty. Almost. 0.1 percent of for example 2 GB is 2 MB. Should be enough to store nothing but the volume name and the information that there is nothing.
BTW, you are mixing all up. Error correction is part of the low-level format. It does not account into the 512 bytes user data. Sector size is fixed, I said this already.
If you like pre-allocated storage so much, you can use PFS3. It allocates 20% of the partition from the beginning. On the other hand, it uses the remaining space for data only. All meta-data is stored in the 20%.
This means that on other file systems more space than the file size divided by sectorsize is needed for each file while with PFS3 a file occupies exactly this space only.
-
I'm not interested in pre-allocated storage, but how a file system and all of its overhead takes virtually no space.
-
I'm not interested in pre-allocated storage, but how a file system and all of its overhead takes virtually no space.
With GVP there shouldn't be 4gb HD limit, only limit should be fast file systems's 2gb partition limit
-
With GVP there shouldn't be 4gb HD limit, only limit should be fast file systems's 2gb partition limit
So a raw hard drive from the factory when subsequently formatted in FAT, FAT32, NTFS, ,FFS, SFS, etc. on a GVP has virtually the full capacity of the new unformatted hard drive after any file system is then applied?
-
I'm not interested in pre-allocated storage, but how a file system and all of its overhead takes virtually no space.
Like I said, it takes its space when it's needed. For example to store a file of 500 bytes it needs two sectors, not one as you might expect.
-
Ok, back in town. HDToolBox riding gvpscsi.device reports the following about this "4GB" drive after Read Configuration:
File Name: drive definitions
Manufacturer's Name: SGI
Drive Name: Seagate ST34572W
Drive Revision: 0878
Cylinders: 918
Heads: 1
Blocks Per Track: 9674
Blocks Per Cylinder: 9674
Size: 241225K (235MB)
Park Head Where? (Cylinder): 918
Information on this drive:
http://pbclub.pwcsite.com/PBInfo/PB%20Info%20Site/pb/harddrive1/34572wovw.asp.htm
Thanks for any help on this.
bp
-
918 * 1 * 9674 * 512 = 4,546,934,784 Bytes
= 4.547 GB = 4.235 GiB = 4.0 GiB + 235 MiB
So everything is right so far.
In order to stay below 4 GiB, just reduce the number of cylinders by 51.
867 * 1 * 9674 * 512 = 4,294,327,296 Bytes = 3.999 GiB.
(2 ^ 32 = 4,294,967,296; that's the magic limit)
Edit: given that the drive is bigger than 4GB and is not yet installed (which means that changing values does not destroy existing data), you could use these completely different values:
Cylinders = 4096
Heads = 1
Blocks per Track = 2048
Blocks per Cyl = 2048
Then you'll get exactly 4 GiB.
-
Thank you!
Now that that's sorted, 2GB is the max partition size for AmigaOS 3.1, yes?
I am using HDToolBox. I also have GVP's FaaaaaaastPrep app, can I ignore that in setting this up?
Thanks.
bp
-
Now that that's sorted, 2GB is the max partition size for AmigaOS 3.1, yes?
AFAIK FFS does not have a partition size limit. But some old programs (including the Commodore Installer) refuse to copy data to a partition which has more than 2 GB of free space. Therefore it is a good idea to limit the partition to 2 GB, then there never can be more than 2 GB free.
I am using HDToolBox. I also have GVP's FaaaaaaastPrep app, can I ignore that in setting this up?
I don't know what Fa...astPrep does. As long as the controller is RDB-compatible, HDToolbox should be fine.
-
Just as an aside, just be mindful of the different connections between a W ref and a WC
Connections
1 x Storage - Ultra Wide SCSI - 80 pin Centronics (SCA-2) WC
1 x Storage - Ultra Wide SCSI - 68 pin HD D-Sub (HD-68) W
Just that the WC may not be suitable for your Amiga. I say may not. I am no expert, just that I had problems buying drives and then finding I couldn't fit them. And I really only ever bothered with 2.1s cus I had real probs with the bigger drives. Even after I thought I had got them working, they suddenly became corrupt. And that was with a GVP on a 2000.