R4: setting a swap file

R4: setting a swap file

[Matias Seco]

if we would like to set a swap file through:

dd if=/dev/zero of=/swapfile1 bs=<int number (kb)> count=<bs*int number>


we should consider bs (block size) equal to cluster size's plugin
value? (4k, 8k, 16k, 32k or 64k)


PS: sorry, if this thread could be off topic from mailinglist scope,
if it is, please notify me :)

Regards,
Matias

Re: R4: setting a swap file

[Edward Shishkin]

On 11/26/2011 05:31 PM, Matias Seco wrote:
> if we would like to set a swap file through:
>
> dd if=/dev/zero of=/swapfile1 bs=<int number (kb)>  count=<bs*int number>
>

Why do you create a swap file via dd from /dev/zero?
Wouldn't be better to create a "hole file" via truncate(2)?
Holes don't occupy any space in a file managed by reiser4
cryptcompress plugin.

>
> we should consider bs (block size) equal to cluster size's plugin
> value? (4k, 8k, 16k, 32k or 64k)
>


Not necessarily.
Clusters are logical blocks in a file which are compressed
independently. If file size is not a multiple of cluster size,
then file's tail will be compressed unless it is not smaller
than cplug->min_size_deflate().

Edward.


>
> PS: sorry, if this thread could be off topic from mailinglist scope,
> if it is, please notify me :)
>
> Regards,
> Matias
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Re: R4: setting a swap file

[Matias Seco]

Perfect!, thanks for the advice

Matias