NASLite Network Attached Storage

System Memory (RAM):
TOTAL USED FREE BUFFERS USAGE

2020M 1973M 47M 47M USED 97%


from 2GB of memory i have a buffer of 47mb, what is going on?

Is this why my network speeds are quick to start, then drop off dramatically?

The memory is being allocated to buffers for read/write performance boost. Think of them as a type of cache for disk reads and writes.

I believe that the high initial read or write you see is because of cache and buffer hits after which the speeds are limited to the HDAs ability to read and write data to the disk. You don't say what speed network you are running or the disks you are using but you can count on around 7MB/sec for a sequential read on a 100Mb/sec network and around 25-35MB/sec on a 1000Mb/sec network. write performance will be about 20% on average lower due to the way a HDA functions and stores data on the platter. The HDAs are the limiting factor in most all things regarding the NAS.

Mike

but then why does it say

memory used 1900mb
buffers 47mb?


surely this means I have only 47mb of memory being used as buffers, so back to my original question, whats using all that memory?

Tony or Ralph will have to comment as to how the memory is allocated in the OS but what does it matter? The thing performs just fine doesn't it and you are not getting any errors about low memory in the logs. My machine has the same basic report for memory available as yours it would appear and I have 512MB.

Keep in mind that UNIX/Linux are setup to take maximum advantage of memory and use as much of it as they can to get the best performance from the hardware. As such they tend to keep any and all processes in memory that are active.

Mike

sounds like i got my answer. maybe just a mis-interpretation of the word buffer, seems like its not a buffer in the sense of I/O but "headroom" buffer.

thx!