diskstats: ignore zram devices on linux systems by default (#2898)

Signed-off-by: DBS-ST-VIT <dbs-st-vit@users.noreply.github.com>
Co-authored-by: DBS-ST-VIT <dbs-st-vit@users.noreply.github.com>

collector/diskstats_linux.go

@@ -36,7 +36,7 @@ const (
 	// See also https://www.kernel.org/doc/Documentation/block/stat.txt
 	unixSectorSize = 512.0
 
-	diskstatsDefaultIgnoredDevices = "^(ram|loop|fd|(h|s|v|xv)d[a-z]|nvme\\d+n\\d+p)\\d+$"
+	diskstatsDefaultIgnoredDevices = "^(z?ram|loop|fd|(h|s|v|xv)d[a-z]|nvme\\d+n\\d+p)\\d+$"
 
 	// See udevadm(8).
 	udevDevicePropertyPrefix = "E:"

collector/diskstats_linux_test.go

@@ -53,7 +53,7 @@ func TestDiskStats(t *testing.T) {
 	*sysPath = "fixtures/sys"
 	*procPath = "fixtures/proc"
 	*udevDataPath = "fixtures/udev/data"
-	*diskstatsDeviceExclude = "^(ram|loop|fd|(h|s|v|xv)d[a-z]|nvme\\d+n\\d+p)\\d+$"
+	*diskstatsDeviceExclude = "^(z?ram|loop|fd|(h|s|v|xv)d[a-z]|nvme\\d+n\\d+p)\\d+$"
 	testcase := `# HELP node_disk_ata_rotation_rate_rpm ATA disk rotation rate in RPMs (0 for SSDs).
 # TYPE node_disk_ata_rotation_rate_rpm gauge
 node_disk_ata_rotation_rate_rpm{device="sda"} 7200