11-29-2013
Well that's a typical example of when a process is suspended for a whole hour waiting for I/O (from the terminal keyboard) which makes it an ideal candidate to be kicked out of RAM when RAM space is tight, and with no need to be swapped back in until you come back, sit down, type something and hit return.
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Hello and thanks in advance.
I have a Sun box with raid 1 on the O/S disks using solaris svm.
I want to unmirror my swap partition, and add the slice on the second disk as an additional swap device. This would give me twice as much swap space.
I have been warned not to do this by some... (3 Replies)
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2. UNIX for Dummies Questions & Answers
ls displays files in tabbed output. Say a directory contains 3 files. ls will list all 3 in one line. So, I expect ls | wc -l to give 1, but it counts the nr of files and gives 3.
Can someone explain how this works? (3 Replies)
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3. Programming
pls explain me how this works....
DECODE (SUBSTR (field, 1, 1),'''', '''''' || field || '''','''' || field || '''')
here field is a column in an oracle table.... (7 Replies)
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4. UNIX for Dummies Questions & Answers
When I try to execute script, I get message:
>aa.pl
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Thank you,
Alex Z (4 Replies)
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5. Red Hat
free -m : 1023 total swap space
created default partition /dev/sdb1 50M using fdisk. i did write the changes.
#mkswap /dev/sdb1
#swapon /dev/sdb1
free -m : 1078 total swap space
this shows that the swap is on
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so why is... (5 Replies)
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6. HP-UX
Hi
I have an integrity machine rx7620 and rx8640 running hp-ux 11.31. I'm planning to fine tune the system:
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I have a program............
#include<stdio.h>
#include<unistd.h>
main()
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}
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8. Solaris
Hi All,
I want to know how to understand the actual swap size.
My o/p shows as below
root@ecovs1a # swap -s
total: 4546056k bytes allocated + 358856k reserved = 4904912k used, 5046688k available
root@ecovs1a # swap -l
swapfile dev swaplo blocks free
/dev/md/dsk/d31 ... (9 Replies)
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9. Solaris
Hi Solaris Folks :),
I need to calculate the swap usage on solaris server, please let me understand the output of below swap -s and swap -l commands.
$swap -s
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$swap -l
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10. AIX
Please take your time to answer/comment. no urgency. it would help upcoming sysadmins like me in understanding how things work in real time.
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Middleware: Weblogic/WAS
Database: Oracle DB/IBM DB2
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LEARN ABOUT MINIX
biodone
biodone(9F) Kernel Functions for Drivers biodone(9F)
NAME
biodone - release buffer after buffer I/O transfer and notify blocked threads
SYNOPSIS
#include <sys/types.h>
#include <sys/buf.h>
void biodone(struct buf *bp);
INTERFACE LEVEL
Architecture independent level 1 (DDI/DKI).
PARAMETERS
bp Pointer to a buf(9S) structure.
DESCRIPTION
biodone() notifies blocked processes waiting for the I/O to complete, sets the B_DONE flag in the b_flags field of the buf(9S) structure,
and releases the buffer if the I/O is asynchronous. biodone() is called by either the driver interrupt or strategy(9E) routines when a buf-
fer I/O request is complete.
biodone() provides the capability to call a completion routine if bp describes a kernel buffer. The address of the routine is specified in
the b_iodone field of the buf(9S) structure.
If such a routine is specified, biodone() calls it and returns without performing any other actions. Otherwise, it performs the steps
above.
CONTEXT
biodone() can be called from user or interrupt context.
EXAMPLES
Generally, the first validation test performed by any block device strategy(9E) routine is a check for an end-of-file (EOF) condition. The
strategy(9E) routine is responsible for determining an EOF condition when the device is accessed directly. If a read(2) request is made
for one block beyond the limits of the device (line 10), it will report an EOF condition. Otherwise, if the request is outside the limits
of the device, the routine will report an error condition.
In either case, report the I/O operation as complete (line 27).
1 #define RAMDNBLK 1000 /* Number of blocks in RAM disk */
2 #define RAMDBSIZ 512 /* Number of bytes per block */
3 char ramdblks[RAMDNBLK][RAMDBSIZ]; /* Array containing RAM disk */
4
5 static int
6 ramdstrategy(struct buf *bp)
7 {
8 daddr_t blkno = bp->b_blkno; /* get block number */
9
10 if ((blkno < 0) || (blkno >= RAMDNBLK)) {
11 /*
12 * If requested block is outside RAM disk
13 * limits, test for EOF which could result
14 * from a direct (physio) request.
15 */
16 if ((blkno == RAMDNBLK) && (bp->b_flags & B_READ)) {
17 /*
18 * If read is for block beyond RAM disk
19 * limits, mark EOF condition.
20 */
21 bp->b_resid = bp->b_bcount; /* compute return value */
22
23 } else { /* I/O attempt is beyond */
24 bp->b_error = ENXIO; /* limits of RAM disk */
25 bp->b_flags |= B_ERROR; /* return error */
26 }
27 biodone(bp); /* mark I/O complete (B_DONE) */
28 /*
29 * Wake any processes awaiting this I/O
30 * or release buffer for asynchronous
31 * (B_ASYNC) request.
32 */
33 return(0);
34 }
...
SEE ALSO
read(2), strategy(9E), biowait(9F), ddi_add_intr(9F), delay(9F), timeout(9F), untimeout(9F), buf(9S)
Writing Device Drivers
WARNINGS
After calling biodone(), bp is no longer available to be referred to by the driver. If the driver makes any reference to bp after calling
biodone(), a panic may result.
NOTES
Drivers that use the b_iodone field of the buf(9S) structure to specify a substitute completion routine should save the value of b_iodone
before changing it, and then restore the old value before calling biodone() to release the buffer.
SunOS 5.10 23 Apr 1996 biodone(9F)