Linked by Thom Holwerda on Sun 18th May 2008 15:32 UTC, submitted by sjvn
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When looking at the public information about ZFS (I can't read the source) from Sun blogs and other docs, I always wondered how they kept RAM requirements in check, because a log-structured filesystem has to keep a more-efficient block mapping structure in memory in order to get performance for common applications (the log by itself doesn't give you a good searchable structure). I figured it would be a little more expensive (maybe 2X) of a traditional filesystem. But needing a 2GB machine to use ZFS?? Yikes!
I guess it makes sense... Sun is a hardware company after all. While they lack all the fancy CoW and transactional features, at least the Linux filesystems and NTFS won't eat your machine.
I guess it makes sense... Sun is a hardware company after all. While they lack all the fancy CoW and transactional features, at least the Linux filesystems and NTFS won't eat your machine.
All of this talk reminds me of when NT 3.1 came out. People were aghast that it wanted something like 16 MB to perform well, back when that extra 8 MB was around $300. However, keeping in mind the horrors of 16 bit Windows, it was better to see MS try to do better even if they were a little ahead of the hardware curve. The hardware curve caught up and the investment paid off.
I figured it would be a little more expensive (maybe 2X) of a traditional filesystem. But needing a 2GB machine to use ZFS?? Yikes!
According to the ZFS Admin Manual (p. 41), you can use ZFS on [Open]Solaris with only 0.5 GB of RAM. They recommend a minimum of 1 GB, though, for the best performance (more is always better). Not sure where you get the "need 2 GB" meme. Even on FreeBSD 7, you only "need" 1 GB of RAM.
RE[2]: ZFS RAM requirements
by PlatformAgnostic on Mon 19th May 2008 08:47
in reply to "RE: ZFS RAM requirements"




Member since:
2006-01-02
When looking at the public information about ZFS (I can't read the source) from Sun blogs and other docs, I always wondered how they kept RAM requirements in check, because a log-structured filesystem has to keep a more-efficient block mapping structure in memory in order to get performance for common applications (the log by itself doesn't give you a good searchable structure). I figured it would be a little more expensive (maybe 2X) of a traditional filesystem. But needing a 2GB machine to use ZFS?? Yikes!
I guess it makes sense... Sun is a hardware company after all. While they lack all the fancy CoW and transactional features, at least the Linux filesystems and NTFS won't eat your machine.