Performance issues with 8.0 ZFS and sendfile/lighttpd

[Miroslav Lachman]

Ivan Voras wrote:
> Miroslav Lachman wrote:

[..]

>> I have more strange issue with Lighttpd in jail on top of ZFS.
>> Lighttpd is serving static content (mp3 downloads thru flash player).
>> Is runs fine for relatively small number of parallel clients with
>> bandwidth about 30 Mbps, but after some number of clients is reached
>> (about 50-60 parallel clients) the throughput drops down to 6 Mbps.
>>
>> I can server hundereds of clients on same HW using Lighttpd not in
>> jail and UFS2 with gjournal instead of ZFS reaching 100 Mbps (maybe
>> more).
>>
>> I don't know if it is ZFS or Jail issue.
>
> Do you have actual disk IO or is the vast majority of your data served
> from the caches? (actually - the same question to the OP)

I had ZFS zpool as mirror of two SATA II drives (500GB) and in the peak 
iostat (or systat -vm or gstat) shows about 80 tps / 60% busy.

In case of UFS, I am using gmirrored 1TB SATA II drives working nice 
with 160 or more tps.

Both setups are using FreeBSD 7.x amd64 with GENERIC kernel, 4GB of RAM.

As the ZFS + Lighttpd in jail was unreliable, I am no longer using it, 
but if you want some more info for debuging, I can set it up again.

Miroslav Lachman