SSD Cache drive.

[Ddemonrider]

I am new to Freenas, would i gain any performance by adding a 32 GB SSD drive for cache, i use it for cifs sharing?

i have 2x2TB disk in mirror.

Thanks.

 

[ben]

I assume you mean read cache?

If you regularly read different files in excess of the size of that drive... not much. However, if your active data (say, an MP3 library) is smaller than that drive, you could gain appreciably better read speed. However, this only matters if you're already saturating disk read speed.

If you're thinking about that as a log device... bad idea. On 8.2, a single log device can never be removed or allowed to fail, because it will take the entire pool with it.

 

[Ddemonrider]

Yes as read cache, i use it as a 1080p movie share. I just wounder if i get better speed, from nas I've tried to tune it. but i can't get more. I've entered the following to sysctl:

kern.ipc.maxsockbuf 67108864
kern.ipc.somaxconn 16384
net.inet.tcp.inflight.enable 0
net.inet.tcp.recvbuf_auto 1
net.inet.tcp.recvbuf_inc 524288
net.inet.tcp.recvspace 131072
net.inet.tcp.rfc1323 1
net.inet.tcp.sendbuf_auto 1
net.inet.tcp.sendbuf_inc 65536
net.inet.tcp.sendspace 131072
net.inet.udp.recvspace 65536
net.inet.udp.maxdgram 57344
net.local.stream.recvspace 65536
net.local.stream.sendspace 65536
net.inet.tcp.recvbuf_max 16777216
net.inet.tcp.sendbuf_max 16777216

and in cifs i've entered this:

socket options = TCP_NODELAY IPTOS_LOWDELAY SO_KEEPALIVE SO_RCVBUF=131072 SO_SNDBUF=131072 IPTOS_THROUGHPUT
read raw = yes
write raw = yes
oplocks = yes
max xmit = 131072
write cache size = 131072

Now i have about 58 Mb/second when writing to NAS and 55 Mb/second when reading from NAS. Just trying to get more speed :)

 

[ben]

I don't have an experience with sysctls or tunables, sorry. You might be able to benefit from a cache in that situation, but I can't say for sure. The specs in your signature do seem good, otherwise.

 

[Ddemonrider]

Thanks for the answer. I try google some more, i don't know how to benchmark i am a noob.

Perhaps others have any hint's for me.

 

[toddos]

Do you really need more speed, though? Even a raw blu-ray rip won't require more than ~60Mbps (little-b bits), which is 7.5MB/s (big-B Bytes). At 58MB/s (I assume you mean big-B Bytes), you could stream 7 simultaneous 1080p max-bitrate movies.

 

[Ddemonrider]

Well it's always nice to see how much it can deliver, more speed=less copy time=more time to watch movie's . Just trying to make a little home nas. I'm planning on using it for more than just Movie's. I'm just trying to learn how to install and tweak it. I think i'm gonna use Freenas as a storage unit for vmware ESX 5 server with 10-15 Vm's. So i guess my next step is to install it on a proliant DL 580 G5, with a hp d2700 disk enclosure, and copy the vm,s to it. I know i can't compair a home setup like mine to the one i plan on making. Just wanted to learn how 2 use it. And i like i the Raidz possibilities it have. I am looking forward to try it with Iscsi, and with se how it handles a lot of I/O