gjournal

[Miroslav Lachman]

Radim Kolar wrote:
>>Kde jsi dosel k tomu, ze by velikost journalu mela byt 2/3 velikosti RAM? Ja
>>tomu zas az tak moc nerozumim, ale tohle vidim prvne a nikdy jsem necetl nic
>>o spojitosti s RAM.
> 
> http://www.freebsd.org/doc/en/articles/gjournal-desktop/article.html
> tady treba doporucuji journal = ramsize x 3.3, nekde jinde jsem cetl
> 2/3 a to nestacilo.

Tak a ted co z toho je realita?

Ivan Voras:
The calculation for this involves disk bandwidth multiplied by the 
"journal flush interval", multiplied by two because there are two 
journal areas, and it's usually recommended that it should be at least 1 
GB.

Pawel Jakub Dawidek (autor gjournalu a portu ZFS):
The size of the journal don't depend on file system size. It more depend
on your disk speed and file system load. For example your disk can write
at 60MB/s. Journal switch time is 10 seconds. The journal provider has
to have place to keep two journals (active and inactive). So bascially
you need 60*10*2MB + gjournal headers. I think 2GB is a safe default.

http://lists.freebsd.org/pipermail/freebsd-fs/2006-June/002016.html

Mirek