12-17-2007
I am sorry. I think I confused everyone. This is what I actually meant to say..
Usually a hard disk keeps spare sectors that are not visible to the user. Whenever the disk encounters a bad block the disk internally replaces these bad blocks from the spare sectors. This operation is completely translucent to the user. There seems to be a specific number of spare sectors on any hard disk that is used for recovering from bad blocks. But once the disk runs out of spare sectors in the process of replacing bad blocks, all future bad blocks will become medium errors (unrecoverable). If the number of available spare sectors can be found then the user can be informed much earlier that its time to backup this disk as it would soon become faulty.
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Hi, guys !
Could someone clarify one thing for me:
I start machine from disk0, and want to check the /etc/vfstab on disk1. How do i do it ?
Tried to write:
cd /
mount /dev/dsk/c0t1d0s0 /mnt
But if I do cd /mnt, it is empty. I expected to see disk1 there ? Or am I wrong ?
How do I... (3 Replies)
Discussion started by: DGoubine
3 Replies
2. Filesystems, Disks and Memory
I found a document: Bad block HOWTO for smartmontools
My hard drive is Maxtor:
root]# fdisk -lu /dev/hda
Disk /dev/hda: 81.9 GB, 81964302336 bytes
255 heads, 63 sectors/track, 9964 cylinders, total 160086528 sectors
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x3f4e3f4d
... (0 Replies)
Discussion started by: justinian
0 Replies
3. UNIX for Dummies Questions & Answers
Hi Guys,
I have a failing 4gb (c0t5d0) drive that contains lvol4 -8 on hp-ux. It's not the boot disk but is part of VG00 volume group. Within that group, I have a disk (c0t4d0) of the same size that has 1 lvol on it for swap(4gb) I also have a seperate 1.5 gb swap volume on another physical disk... (1 Reply)
Discussion started by: rees_a
1 Replies
4. Linux
Hi all,
I'm kind of new to programming in Linux & c/c++. I'm currently writing a FileManager using Ubuntu Linux(10.10) for Learning Purposes. I've got started on this project by creating a loopback device to be used as my virtual hard disk. After creating the loop back hard disk and mounting it... (23 Replies)
Discussion started by: shen747
23 Replies
5. Boot Loaders
i'm writing some code to simulate the boot progress after power on
but when i try to read the 2nd sector from a floppy disk, this operation always fail with ah=0x80h which means timeout, how can i get over this problem?
my code would be like this:
$ cat boot.S
.code16
#define SETUPLEN 4... (0 Replies)
Discussion started by: wljackhero
0 Replies
6. Linux
i'm writing some code to simulate the boot progress after power on
but when i try to read the 2nd sector from a floppy disk, this operation always fail with ah=0x80h which means timeout, how can i get over this problem?
my code would be like this:
$ cat boot.S
.code16
#define SETUPLEN 4... (0 Replies)
Discussion started by: wljackhero
0 Replies
7. UNIX for Advanced & Expert Users
i'm writing some code to simulate the boot progress after power on
but when i try to read the 2nd sector from a floppy disk, this operation always fail with ah=0x80h which means timeout, how can i get over this problem?
my code would be like this:
$ cat boot.S
.code16
#define SETUPLEN 4... (0 Replies)
Discussion started by: wljackhero
0 Replies
8. AIX
Hello,
I have DS4000 IBM SAN Storage ( aka FastT Storage )
One of my disks has failed and I had a hot spare disk covering all the arrays. As the disk failed, immediately the hotspare disk took over the failed disk ( see the JPEG in the attachment )
My Question: How can I make the hotspare... (1 Reply)
Discussion started by: filosophizer
1 Replies
9. Shell Programming and Scripting
Hi All,
i am trying to get sectors,cylinders,track..etc information of all present disks out of solaris machine using prtvtoc command .
Output of ptrvtoc command is as below :
bash-3.2# prtvtoc /dev/dsk/c1t0d0s0
* /dev/dsk/c1t0d0s0 partition map
*
* Dimensions:
* 512 bytes/sector... (2 Replies)
Discussion started by: omkar.jadhav
2 Replies
10. Solaris
Hi all,
I have a EFI disk and it is use in zfs pool.
partition> p
Volume: rpool
Current partition table (original):
Total disk sectors available: 1172107117 + 16384 (reserved sectors)
Part Tag Flag First Sector Size Last Sector
0 usr wm ... (8 Replies)
Discussion started by: javanoob
8 Replies
BAD144(8) System Manager's Manual BAD144(8)
NAME
bad144 - read/write DEC standard 144 bad sector information
SYNOPSIS
bad144 disktype disk [ sno [ bad ... ] ]
DESCRIPTION
Bad144 can be used to inspect the information stored on a disk that is used by the disk drivers to implement bad sector forwarding. The
format of the information is specified by DEC standard 144, as follows.
The bad sector information is located in the first 5 even numbered sectors of the last track of the disk pack. There are five identical
copies of the information, described by the dkbad structure. Only the first of these copies is used.
Replacement sectors are allocated starting with the first sector before the bad sector information and working backwards towards the begin-
ning of the disk. A maximum of 126 bad sectors can be supported. The position of the bad sector in the bad sector table determines which
replacement sector it corresponds to.
The bad sector information and replacement sectors are conventionally only accessible through the ``h'' file system partition of the disk.
If that partition is used for a file system, the user is responsible for making sure that it does not overlap the bad sector information or
any replacement sectors.
The bad sector structure is as follows:
struct dkbad {
long bt_csn; /* cartridge serial number */
u_short bt_mbz; /* unused; should be 0 */
u_short bt_flag; /* -1 => alignment cartridge */
struct bt_bad {
u_short bt_cyl; /* cylinder number of bad sector */
u_short bt_trksec; /* track and sector number */
} bt_bad[MAXBAD];
};
Unused slots in the bt_bad array are filled with all bits set, a putatively illegal value. MAXBAD (in <sys/dkbad.h>) may be tuned locally
to reduce the space required to hold the bad-sector file in memory. It may not be greater than 126, which uses the whole disk sector. Bad
sectors past MAXBAD may be included by the formatter, but replacement sectors will not be used until MAXBAD is increased.
Bad144 is invoked by giving a device type (e.g. rk07, rm03, rm05, etc.), and a device name (e.g. hk0, hp1, etc.). It reads the first sec-
tor of the last track of the corresponding disk and prints out the bad sector information. It may also be invoked giving a serial number
for the pack and a list of bad sectors, and will then write the supplied information onto the same location. Note, however, that bad144
does not arrange for the specified sectors to be marked bad in this case. This option should only be used to restore known bad sector
information which was destroyed.
New bad sectors can be added by running the standard DEC formatter in section ``bad.''
SEE ALSO
badsect(8)
BUGS
Not all drivers support bad-sector forwarding on the PDP-11.
It should be possible to both format disks on-line under UNIX and to change the bad sector information, marking new bad sectors, without
running a standalone program.
The bootstrap drivers used to boot the system do not understand bad sectors or handle ECC errors. This means that none of these errors can
occur when reading the file /unix to boot. Sector 0 of the disk drive and the file /boot in the root file system of that drive must also
not have any of these errors in it.
The drivers that write a system core image on disk after a crash do not handle errors; thus the crash dump area must be free of errors and
bad sectors.
3rd Berkeley Distribution BAD144(8)