I have three 3TB 5400rpm HDD's running on RAID 5 in my Ubuntu server VM as my NAS. I recently just hooked up this NAS Server directly to my Desktop via 10GB Ethernet cards and fiber optic cable (thought it would be fun). My PC to Server speeds jumped up significantly but not as high as I had expected (and seen on other's systems) It then dawned on me that now my bottleneck is the medium the data is being transferred to/from (ie. HDD's).

So my question is can I put a SSD into my server to cache or buffer (not sure which term is the most correct) the data being sent from my PC. Basically I want to dump everything I am transferring onto the SSD and then have the server automatically push it to the RAID 5 disks. I figure the way I want to do it won't boost read speeds when I access data on my NAS but I am more concerned about pushing data to my NAS faster

I have a rough idea how I could do it myself and just automate it w/ scripts but I was hoping someone knew something that could help or knew where I can read up on something like this.

**I could probably make a RAMDisk on my PC to boost transfer speed from server to PC couldn't I?

1 Answer 1


For SSD caching in Linux there's bcache, but that's designed to help with random access, since that's where SSDs really outperform HDDs. It passes big sequential transfers straight through to the disk without caching, because they'd create lots of additional wear on the SSD without that much of a performance increase.

If you want uploads to your NAS to finish as quickly as possible, your best bet would be to add more RAM to it. Linux uses "free" RAM (basically anything not being used by programs) for disk caches and buffers, so with enough RAM, your whole uploaded file can be buffered in memory as quickly as it can be received from the network.

  • 1
    I didn't even realize it would be stored in the RAM, that makes it a lot simpler. I am assuming this is done automatically by (in my case) Ubuntu and doesn't require an effort on my end apart from adding more RAM? Does Windows also use RAM for disk caches? Mar 2, 2016 at 3:54
  • 1
    Yes, all modern operating systems do.
    – Wyzard
    Mar 2, 2016 at 3:55
  • 1
    huh, ok. That was a lot easier than I thought. I guess that means I should give my VM more than 256 MB of memory! Thanks that answered my questions. Mar 2, 2016 at 4:01

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .