[clug] partition tables in memory

[Kim Holburn]

Just to make this clear,

The normal method of making swap is AFAIK :
1) make a partition,
2) run say:
    mkswap /dev/sda8
3) then:
   swapon /dev/sda8.

But in this case the kernel cannot see the partition:
# l /dev/sda[78]
brw-rw----    1 root     disk       8,   7 Mar 15  2002 /dev/sda7
brw-rw----    1 root     disk       8,   8 Mar 15  2002 /dev/sda8
# cat /proc/partitions
major minor  #blocks  name     rio rmerge rsect ruse wio wmerge wsect 
wuse running use aveq

    8     0   35545728 sda 688792 1156813 14762148 7980560 13470841 
37027503 404260530 43342130 1 7507370 51338980
    8     1     979933 sda1 112258 395055 4058776 542960 59256 312356 
3012928 1375120 0 443990 1923240
    8     2          1 sda2 0 0 0 0 0 0 0 0 0 0 0
    8     5    4883728 sda5 382733 622455 8041500 6313750 10902982 
16989694 223279552 30965690 1 5792500 37274880
    8     6    2931831 sda6 154552 52632 1657500 360210 843641 4091059 
39488440 2485030 0 946790 2845000
    8     7     979933 sda7 39198 86298 1003524 763420 1664957 15634399 
138479640 8516260 0 543100 9294370
# fdisk -l /dev/sda

Disk /dev/sda: 255 heads, 63 sectors, 4425 cylinders
Units = cylinders of 16065 * 512 bytes

    Device Boot    Start       End    Blocks   Id  System
/dev/sda1             1       122    979933+  82  Linux swap
/dev/sda2           123      1704  12707415    5  Extended
/dev/sda5           123       730   4883728+  83  Linux
/dev/sda6           731      1095   2931831   83  Linux
/dev/sda7          1096      1217    979933+  83  Linux
/dev/sda8          1218      1704   3911796   82  Linux swap

So when I do mkswap:

# mkswap  /dev/sda8
/dev/sda8: No such device or address

So my question: without rebooting how do I get the kernel to reread the 
partition.  Need I mention this is the boot disk so I can't unmount it.


Kim

On 2005 Apr 16, , at 2:36 PM, Kim Holburn wrote:

> Hi,
>
> I have a linux server which needed more swap.  I added a new swap 
> partition wrote the new partition table but it doesn't show up in 
> /proc/partitions so I can't mkswap etc.
> # mkswap  /dev/sda8
> /dev/sda8: No such device or address
>
> Is there any way to get the kernel to reread the partition table or do 
> I have to do the windows thing and reboot (and lose my uptime;-( )?
>
> Dell debian stable kernel 2.4.26 #1 SMP
>
> Kim
> -- 
> Kim Holburn
> Network Manager,  National ICT Australia Ltd.
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-- 
Kim Holburn
Network Manager,  National ICT Australia Ltd.
Ph: +61 2 61258620 M: +61 417820641 F: +61 2 6230 6121 aim://kimholburn
Email: kim.holburn at anu.edu.au  - PGP Public Key on request  
callto://kholburn
Cacert Root Cert: http://www.cacert.org/index.php?id=16 -> 
http://www.cacert.org/cacert.crt
Aust. Spam Act: To stop receiving mail from me: reply and let me know.

Use ISO 8601 dates [YYYY-MM-DD] 
http://www.saqqara.demon.co.uk/datefmt.htm
Democracy imposed from without is the severest form of tyranny.
                           -- Lloyd Biggle, Jr. Analog, Apr 1961