Can a PIII Handle RAID-Z

Fuzzball

New Member


Messages: 11

I have an old PIII 900MHz computer I use as a server that I've been running FreeBSD on for years now. The time has come to upgrade my RAID array to something a bit larger. I was considering using three 1.5TB HDDs in a ZFS RAID-Z.

Would RAID-Z overtax the P3 or would the system be able to handle streaming a DVD quality MPEG2 stream over the network?
 

Djn

Well-Known Member

Reaction score: 67
Messages: 392

Another bigger hurdle might actually be RAM - ZFS likes to have a significant lot of it. If you've got less than 1 GB, you might be better off with graid3 + gjournal + UFS2.

I think 768MB can be made to work, but no guarantees.
 

mbs

New Member


Messages: 7

I've tried a RAID-Z with 3 free IDE Hard Drives on an ultra sparc 5 (Sun 64 bits processor at 300 mHz and only 64MB of memory)

I was limited by the in-build IDE controller. I was at something like 3MB/s which should be OK for DVDs.

I am using the same disks on an AMD opteron 165 with 2GB of RAM and the performances are not the same (60MB/s) I did not notice an excessive RAM usage by ZFS.

I think that you should give a try to RAID-Z on your Pentium III box. It should works with acceptable performances.
 

Djn

Well-Known Member

Reaction score: 67
Messages: 392

I refer you to the tuning guide when it comes to RAM usage. Who knows what Sun did to make it run on 64MB, but that's about an order of magnitude out from what you'll need on FreeBSD.

&quot said:
To use ZFS, at least 1GB of memory is recommended (for all architectures) but more is helpful as ZFS needs *lots* of memory. Depending on your workload, it may be possible to use ZFS on systems with less memory, but it requires careful tuning to avoid panics from memory exhaustion in the kernel.
edit:
Actually ...
&quot said:
Currently, the minimum amount of memory recommended to install a Solaris system is 768
Mbytes. However, for good ZFS performance, at least one Gbyte or more of memory is
recommended.
That's not to say you can't use it on less - there's a difference between "minimum recommended" and "lowest technically possible".
 

none

Active Member

Reaction score: 5
Messages: 142

I tried sometime on a Pentium II 300MHz and no more than 400MB of ram. small disks though.

but this has some time ...

none
 
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