Hard drive question

  • hi everyone i was thinking about upgrading my 80 gig ide drive and i was wondering whether or not the drive performance mattered at all like i was thinking about putting my wd green in my box or should i put a wd black in it instead

  • Drive speed will matter if you are running squid cache or some package that uses it.  Also makes more of a difference the more clients are using your pfsense.  In those cases, SSD would probably be best.  Otherwise, your drive will make little difference if any.  The biggest consideration for a drive otherwise should probably just be reliability.  Not necessarily size or speed.  I like the reliability of WD Black.  I also favor small industrial SLC SSDs if you can get one cheap.

  • i was planning on using a 1 tb for web cache maybe higher

  • Well - My understanding of pfsense is that cache size is dependent on memory size because the disk cache has to be indexed in memory.
    I had also figured out that the ram available for that index needs to be 4% - 6% or so the size of the disk cache.
    For me, a 50GB cache seemed to use alot of ram.

    My point is I think you might need a ton or RAM to have a 1TB cache size and have it work.

    Maybe a guru who knows more than me will chime in.

  • Netgate Administrator

    Going to the source:
    Says ~ 10MB or RAM per 1GB of cache (1%). So for a 50GB cache it might be expected to use 500MB of RAM which doesn't seem like that much. Certainly it's way below the 4-6% you saw so maybe that wiki page is out of date, or maybe your Squid settings were unusual.  :-\

    However that does mean a 1TB cache will require at the very least 10GB of RAM which may be completely impractical.  ;)



  • Its going to be more than 1% for sure.  A machine with 4GB RAM I was using was maxing out available ram very quickly with cache and like I was saying, the drive is quite small.

    Thats the bad news.  The worse news is that a 1TB cache, if you did ever manage to fill it, would probably be 99.99% stale cache and never get you past 5% cache hit anyway.

    Still - If your internet is slow as a snail, a 5% improvement might be worth fussing about, but I'd have to say pick a smallish extremely durable SSD for that.

  • Netgate Administrator

    Totally agree. Running squid doesn't help much with bandwidth use or apparent connection speed. At least with normal web use. Not as much as you might hope! That's coming from little experience though.  :P


  • I am forced to use Squid as Dansguardian needs it. But I have turned on the "null" option so that there is no real hard drive caching. Have 110/20 Maps Internet and don't see a need to cache anything. Now if only Dansguardian could be configured to run without squid

  • WD Green HDs love to spin down and like to burn out early. They have a lot of complaints on NewEgg and you hear horror stories from around the Internet.

  • Yeah - WD Green drives are interesting to use.
    The ones I've had mounted in eSATA enclosures just keep running.  No problems at all.
    I've got 5.5 years and no errors on a pair in a fan cooled enclosure with a good power supply.
    However - They suck for anything other than archiving.
    But definitely not good as a boot drive.  I'd recommend SSD or small 7200RPM WD laptop drive.
    Seek rates will matter alot with squid.

Log in to reply