published on in Featured Geekyness FreeBSD kickassery Samba ZFS

freebsd 8 0 a great nas server

I need to share this. When I google for “Samba performance”, I never see real numbers, real configuration files, or real hardware environments. All I read are anecdotal recollections, and that is not good enough. I like numbers, and I’ll let the numbers speak for themselves:

    > netstat -I em0 -w 1
                input          (em0)           output
       packets  errs      bytes    packets  errs      bytes colls
         90166     0   98762637      95363     0    5332847     0
         18131     0   24713156      20042     0    1123684     0
             4     0        310          1     0        178     0
             8     0        518          1     0        178     0
         10153     0   10952920      10696     0     598129     0
         92990     0  102837002      98476     0    5514994     0
         92025     0  102680574      97277     0    5439496     0
         92080     0  101799874      97403     0    5448637     0
         75348     0   90861608      80972     0    4537737     0
         90895     0  100323946      95781     0    5360948     0
         89313     0   97371154      94364     0    5278618     0
         81363     0   89229738      85861     0    4803589     0
             2     0        126          3     0        286     0

I was so shocked that I had to use gstat and zpool iostat to verify the information:

    dT: 1.002s  w: 1.000s  filter: da0
     L(q)  ops/s    r/s   kBps   ms/r    w/s   kBps   ms/w   %busy Name
       35   1476      0      0    0.0   1476 188421   23.7  100.0| da0

    > zpool iostat  1
                   capacity     operations    bandwidth
    pool         used  avail   read  write   read  write
    ----------  -----  -----  -----  -----  -----  -----
    tank        5.68T  4.32T      1     81   250K  10.1M
    tank        5.68T  4.32T      0  1.37K      0   175M
    tank        5.68T  4.32T      0  1.44K      0   184M
    tank        5.68T  4.32T      0  1.44K      0   184M
    tank        5.68T  4.32T      0  1.44K      0   184M
    tank        5.68T  4.32T      0  1.44K      0   184M
    tank        5.68T  4.32T      0  1.44K      0   184M
    tank        5.68T  4.32T      0  1.44K      0   184M

This is all through Samba (3.3.9), There was no local work being done. I unfortunately didn’t configure MRTG correctly, so it had built a malformed graph while all this happened. Having a picture from all of this would have been nice.

The underlying storage is a SATABoy2 RAID6 array, with a simple “flat” ZFS filesystem (version 13). As cheap as the SATABoy’s are (and come on, they have a terrible IIS web interface), they can at least keep up with the current load.

I have felt that if you are going to use ZFS, you should let it manage the RAID, and not bother with a hardware RAID controller. While the hardware RAID may be faster, ZFS’s ability to self-correct bad blocks is a great feature despite the performance set back. However, RAID6 is pretty good in itself, and having dual parity would ideally reduce the risk of a bad block being detrimental.

One thing I noticed with Samba is it doesn’t seem to be a threaded daemon. When I do a top(1) -H, there are only 2-3 smbd processes, and one of them is running around 30%. Though I don’t really know how well Samba can scale out, this environment only has about 10 users. I would like to see how samba reacts if there are a couple hundred active users. Furthermore, how does a native Windows server handle a couple hundred users? It may handle it a little better, however, I don’t think I would enjoy watching NTFS handling a multi-terabyte volume… it would be like watching a stroke victim eat a bowl of soup. I do admit I am biased and I have no working experience with Windows as a large file server, most of them that I have worked on are horribly limited and underpowered, and no one seems to care if they perform well or not.


CPU information

    Machine class:    amd64
    CPU Model:    Dual Core AMD Opteron(tm) Processor 285
    No. of Cores:    4
    Cores per CPU:

RAM information

    Memory information from dmidecode(8)
    Maximum Capacity: 8 GB
    Number Of Devices: 4
    Maximum Capacity: 8 GB
    Number Of Devices: 4

    INFO: Run `dmidecode -t memory` to see further information.

    System memory summary
    Total real memory available:    8048 MB
    Logically used memory:        2876 MB
    Logically available memory:    5172 MB

    Swap information
    Device          1K-blocks     Used    Avail Capacity
    /dev/da1s1b       8373844      28K     8.0G     0%

Storage information

    Available hard drives:
    cd0:  Removable CD-ROM SCSI-0 device
    cd0: 1.000MB/s transfers
    da2:  Fixed Direct Access SCSI-5 device
    da2: 300.000MB/s transfers
    da2: Command Queueing enabled
    da2: 140009MB (286739329 512 byte sectors: 255H 63S/T 17848C)
    da1:  Fixed Direct Access SCSI-2 device
    da1: 300.000MB/s transfers
    da1: Command Queueing enabled
    da1: 69618MB (142577664 512 byte sectors: 255H 63S/T 8875C)
    da0:  Fixed Direct Access SCSI-5 device
    da0: 200.000MB/s transfers
    da0: Command Queueing enabled
    da0: 10491861MB (21487333120 512 byte sectors: 255H 63S/T 1337524C)

    Raid controllers:
    vendor='LSI Logic (Was: Symbios Logic, NCR)'
    device='SAS 3000 series, 4-port with 1064 -StorPort'
    vendor='QLogic Corporation'
    device='QLA6322 Fibre Channel Adapter'

    Currently mounted filesystems:
    /dev/da1s1a on /
    devfs on /dev
    tank on /tank
    /dev/ufs/EXPORT on /export

    I/O statistics:
           tty             da0              da1              da2             cpu
     tin  tout  KB/t tps  MB/s   KB/t tps  MB/s   KB/t tps  MB/s  us ni sy in id
       0    40 63.61 167 10.36  16.53   2  0.03  61.65   0  0.00   1  0  4  0 94
    INFO: Run iostat(8) or gstat(8) to see live statistics.

    Disk usage:
    Filesystem         Size    Used   Avail Capacity  Mounted on
    /dev/da1s1a         58G    3.4G     50G     6%    /
    devfs              1.0K    1.0K      0B   100%    /dev
    tank               9.8T    5.7T    4.1T    58%    /tank
    /dev/ufs/EXPORT    126G    148K    116G     0%    /export


  • FreeBSD 8.0-RELEASE-p1 FreeBSD 8.0-RELEASE-p1 amd64

  • samba-3.3.9 A free SMB and CIFS client and server for UNIX

Samba 3.3.9 Compile-Time Config

> make showconfig
===> The following configuration options are available for samba-3.3.9:
     LDAP=on "With LDAP support"
     ADS=on "With Active Directory support"
     CUPS=off "With CUPS printing support"
     WINBIND=on "With WinBIND support"
     SWAT=off "With SWAT WebGUI"
     ACL_SUPPORT=on "With ACL support"
     AIO_SUPPORT=on "With Asyncronous IO support"
     FAM_SUPPORT=on "With File Alteration Monitor"
     SYSLOG=on "With Syslog support"
     QUOTAS=on "With Disk quota support"
     UTMP=off "With UTMP accounting support"
     PAM_SMBPASS=on "With PAM authentication vs passdb backends"
     DNSUPDATE=off "With dynamic DNS update(require ADS)"
     DNSSD=off "With DNS service discovery support"
     EXP_MODULES=on "With experimental modules"
     POPT=on "With system-wide POPT library"
     MAX_DEBUG=off "With maximum debugging"
     SMBTORTURE=off "With smbtorture"
===> Use 'make config' to modify these settings

System Tuning

The Kernel

I enabled device polling, and took out debugging in the kernel (Sanders, get it! Mmm, I’m hungry…)

diff /usr/src/sys/amd64/conf/GENERIC /usr/src/sys/amd64/conf/SANDERS
    < makeoptions    DEBUG=-g        # Build kernel with gdb(1) debug symbols
    > options        DEVICE_POLLING





rc.conf (em0 flags)

I want to thank Zilla (see post comments) for the sysctl.conf help.

    ifconfig_em0="inet  netmask polling tso mtu 9194"


        min receivefile size = 131072
        aio read size = 1
        aio write size = 1
        use sendfile = yes
        lock directory = /var/run/samba/
        keepalive = 300

I’m also using LDAP users and group. I wasn’t sure if there would be a noticible performance hit for local users or LDAP users. There doesn’t seem to be one.

We use Active Directory, and since Quest/Vintela still won’t make a FreeBSD client for the Quest Authentication Servers ( a sales rep once told me “There are just too many versions of BSD…”) , I have to use all the open source utilities like OpenSSL, OpenLDAP Client and Kerberos. I don’t mind having to do it, but it is always nice if you can maintain one standard process across ALL systems, and we have a lot more Linux and Solaris systems than FreeBSD. I’m the odd one.

That aside, I use the latest OpenSSL in FreeBSD 8.0, OpenLDAP 2.4.20, and the built-in version of Heimdal Kerberos.

I get similar performance form NFS, however, most desktop users have are either on a Windows or OS X, and CIFS seems to be the unifying network storage protocol.

One thing I have yet to really figure out is configuring Samba to use proper NT ACL’s. However, if you can live with UNIX style permissions, a setup like this is pretty good at serving out lots and lots of data. Maybe that will be next.