Dtrace script to print all written-to files in FreeNAS, and their average write rate every 10 seconds.

writes.dtrace

#!/usr/sbin/dtrace -s

#pragma D option quiet
#pragma D option defaultargs
#pragma D option switchrate=10hz
#pragma D option dynvarsize=4m
#pragma D option cleanrate=30hz

dtrace:::BEGIN
{
    max_secs = 10;
    secs = max_secs;
}


vfs::vop_write:entry
{
        this->vp = args[0];
}

vfs::vop_write:entry
/this->vp/
{
        this->ncp = &(this->vp->v_cache_dst) != NULL ?
                this->vp->v_cache_dst.tqh_first : 0;
        this->fi_name = this->ncp ? (this->ncp->nc_name != 0 ?
                stringof(this->ncp->nc_name) : "<unknown>") : "<unknown>";
        this->mount = this->vp->v_mount; /* ptr to vfs we are in */
        this->fi_fs = this->mount != 0 ? stringof(this->mount->mnt_stat.f_fstypename)
                : "<unknown>"; /* filesystem */
        this->fi_mount = this->mount != 0 ? stringof(this->mount->mnt_stat.f_mntonname)
                : "<unknown>";
}

/* A short cut */
vfs::vop_write:entry
/this->vp == 0 || this->fi_fs == "devfs" || this->fi_fs == 0 ||
this->fi_fs == "<unknown>" || this->fi_name == "<unknown>"/
{
        this->ncp = 0;
}

vfs::vop_write:entry
/this->ncp/
{
        this->dvp = this->ncp->nc_dvp != NULL ?
               (&(this->ncp->nc_dvp->v_cache_dst) != NULL ?
               this->ncp->nc_dvp->v_cache_dst.tqh_first : 0) : 0;
        self->name[1] = this->dvp != 0 ? (this->dvp->nc_name != 0 ?
               stringof(this->dvp->nc_name) : "<unknown>") : "<unknown>";
}

vfs::vop_write:entry
/self->name[1] == "<unknown>" || this->fi_fs == "devfs" ||
this->fi_fs == 0 || this->fi_fs == "<unknown>" || self->name[1] == "/"
|| self->name[1] == 0/
{
        this->dvp = 0;
}

vfs::vop_write:entry
/this->dvp/
{
        this->dvp = this->dvp->nc_dvp != NULL ? (&(this->dvp->nc_dvp->v_cache_dst) != NULL
                ? this->dvp->nc_dvp->v_cache_dst.tqh_first : 0) : 0;
        self->name[2] = this->dvp != 0 ? (this->dvp->nc_name != 0 ?
                stringof(this->dvp->nc_name) : "\0") : "\0";
}

vfs::vop_write:entry
/this->dvp/
{
        this->dvp = this->dvp->nc_dvp != NULL ? (&(this->dvp->nc_dvp->v_cache_dst) != NULL
                ? this->dvp->nc_dvp->v_cache_dst.tqh_first : 0) : 0;
        self->name[3] = this->dvp != 0 ? (this->dvp->nc_name != 0 ?
                stringof(this->dvp->nc_name) : "\0") : "\0";
}

/*
vfs::vop_write:entry
/this->fi_mount != 0/
{
        printf("%s/", this->fi_mount);
}

vfs::vop_write:entry
/self->name[3] != 0/
{
        printf("%s/", self->name[3]);
}

vfs::vop_write:entry
/self->name[2] != 0/
{
        printf("%s/", self->name[2]);
}

vfs::vop_write:entry
/self->name[1] != 0/
{
        printf("%s/%s\n", self->name[1], this->fi_name);
}

vfs::vop_write:entry
{
        self->name[1] = 0;
        self->name[2] = 0;
        self->name[3] = 0;
}
*/

vfs::vop_write:entry
{
    @testAgg[this->fi_name != 0 ? this->fi_name : "unknown"] = sum(args[1]->a_uio->uio_resid);
    @testAgg["TOTAL"] = sum(args[1]->a_uio->uio_resid);

    /* printf("Entry %d\n", args[1]->a_uio->uio_resid); */
        self->name[1] = 0;
        self->name[2] = 0;
        self->name[3] = 0;
}

profile:::tick-1sec
{
    secs--;
}

profile:::tick-1sec
/secs == 0/
{
    secs = max_secs;
    /* normalize from bytes per max_secs to KB/s */
    normalize(@testAgg, 1024*max_secs);
    printf("%-60s Average Write Rate Over %d seconds\n", "File Name", max_secs);
    printa("%-60s %10@d KB/s\n", @testAgg);
    printf("\n\n");
    trunc(@testAgg);
}

Incredibly helpful. Thanks a lot.

via https://forums.freenas.org/index.php?threads/see-iops-and-or-throughput-by-file.40231/