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- Path: sparky!uunet!beartrk!ceilidh!hijo-2!dnichols
- From: dnichols@ceilidh.beartrack.com (Don Nichols (DoN.))
- Newsgroups: comp.sys.3b1
- Subject: Re: Help formatting a Seagate ST251-1
- Message-ID: <1992Jul31.001317.10628@ceilidh.beartrack.com>
- Date: 31 Jul 92 00:13:17 GMT
- References: <1992Jul30.025939.7323@cc.gatech.edu>
- Organization: D and D Data, Vienna Virginia
- Lines: 79
-
- In article <1992Jul30.025939.7323@cc.gatech.edu> gregh@cc.gatech.edu writes:
- >I was in the process of installing a Seagate ST251-1 drive in my att7300,
- >when I noticed that I can only get it formatted to about 30 MB. The specs
- >from Seagate claim that it has a capacity of 42.8 MB. The specs I used to
- >format it were: 820 cyl, 6 tracks per cyl and 17 tracks per sect. Has anyone
- >else has this problem? Any advice on this would be very much appriciated!
-
- You've got two things working against you here. The system uses
- only 16 of the 17 sectors/track for data, reserving the extra in each track
- for replacing bad blocks. The other thing that you may be missing here is
- that a certain portion of the disk is set aside for swap space, even if
- you're using it as a second drive on a modified system. It won't let you
- get the swap space below a certain minimum, and you shouldn't attempt to if
- this is the only drive on your system, since without swap space, the system
- gets rather sick :-)
-
- If it is a second drive, you can do something like what I do, which
- is to make a filesystem on the swap partition on the second drive, and mount
- that as /tmp, so you don't ever have to worry about a program building
- enough files in /tmp to wedge the system with no space left in the root
- partition.
-
- There is also a small amount of disk space used for the VHB (Volume
- Home Block) which tells the system how it is partitioned, what bad-block
- replacement to do, and also provides room in there for the bootstrap loader,
- to keep it out of the way of the working parts of the disk. That way, it
- can't be trashed by a runaway program (or programmer. :-)
-
- If you want to see what has happened with the formatted drive, once
- you are up and running, you can type iv -t /dev/rfp000. (You must be root
- to do this.) Use /dev/rfp010 for the second drive, if that is what this
- is. Here are the results on my system:
-
- ceilidh:csu 19:55# iv -t /dev/rfp000
- Winchester disk
- Volume Name: WINCHE
- 1224 Cylinders. 15 Heads per Cylinder.
- There are 17 Physical Sectors (of 512 bytes) per Track.
- 255 Physical Sectors per Cylinder, 312120 Physical Sectors per Disk.
- There are 8 Logical Blocks (of 1024 bytes) per Track.
- 120 Logical Blocks per Cylinder, 146880 Logical Blocks per Disk.
- The Step Rate supplied to the Controller is 0.
- Partition 0: start Track=0, size (in Blocks)=120
- Partition 1: start Track=15, size (in Blocks)=15000
- Partition 2: start Track=1890, size (in Blocks)=45000
- Partition 3: start Track=7515, size (in Blocks)=86760
- Loader starts at Block 2 (size=24 Blocks).
- Bad Block Table starts at Block 1 (size=1 Blocks).
- The Bad Block Table contains 54 entries.
-
- ceilidh:csu 19:55# iv -t /dev/rfp010
- Second winchester disk
- Volume Name: WINCHE
- 1170 Cylinders. 7 Heads per Cylinder.
- There are 17 Physical Sectors (of 512 bytes) per Track.
- 119 Physical Sectors per Cylinder, 139230 Physical Sectors per Disk.
- There are 8 Logical Blocks (of 1024 bytes) per Track.
- 56 Logical Blocks per Cylinder, 65520 Logical Blocks per Disk.
- The Step Rate supplied to the Controller is 0.
- Partition 0: start Track=0, size (in Blocks)=56
- Partition 1: start Track=7, size (in Blocks)=15000
- Partition 2: start Track=1882, size (in Blocks)=50464
- Bad Block Table starts at Block 1 (size=1 Blocks).
- The Bad Block Table contains 22 entries.
-
- 'csu' is an alternate login for root which gets me tcsh for a shell. This
- way, I don't risk breaking shell scripts run as root. The first disk is a
- Miniscribe 3085, the second is a Priam 190. Each logical block listed above
- is two physical blocks, to add to the confusion. I should have given them
- more imaginative names than "WINCHE", but that was done by the diagonstics
- disk, rather than the alternate formattng by use of iv.
-
- Good Luck
- DoN.
- --
- Donald Nichols (DoN.) | Voice (Days): (703) 704-2280 (Eves): (703) 938-4564
- D&D Data | Email: <dnichols@ceilidh.beartrack.com>
- I said it - no one else | <nichols@nvl.army.mil>
- --- Black Holes are where God is dividing by zero ---
-