BTRFS vs EXT4
Dejo aquí un simple test FIO, el mismo test en el mismo disco, montado y formateado con btrfs y ext4
Lo dejo como log y para que se vea la diferencia, el por que de esta diferencia se puede explicar pero hoy no tengo tiempo.
El disco usado Crucial p510 nuevo de paquete
BTRFS fio test:
fio --filename=fio-test --size=2G --direct=1 --rw=randrw --bs=4k --ioengine=libaio --iodepth=64 --numjobs=16 --group_reporting --name=iops-max-test
iops-max-test: (g=0): rw=randrw, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=libaio, iodepth=64
...
fio-3.41
Starting 16 processes
iops-max-test: Laying out IO file (1 file / 2048MiB)
Jobs: 16 (f=14): [m(3),f(1),m(10),f(1),m(1)][100.0%][r=400MiB/s,w=399MiB/s][r=102k,w=102k IOPS][eta 00m:00s]
iops-max-test: (groupid=0, jobs=16): err= 0: pid=4601: Thu Jan 29 15:35:27 2026
read: IOPS=89.2k, BW=348MiB/s (365MB/s)(16.0GiB/47011msec)
slat (usec): min=2, max=98009, avg=69.69, stdev=147.86
clat (usec): min=42, max=105468, avg=5680.94, stdev=3251.11
lat (usec): min=45, max=105557, avg=5750.62, stdev=3288.03
clat percentiles (msec):
| 1.00th=[ 4], 5.00th=[ 5], 10.00th=[ 5], 20.00th=[ 5],
| 30.00th=[ 5], 40.00th=[ 5], 50.00th=[ 5], 60.00th=[ 6],
| 70.00th=[ 6], 80.00th=[ 6], 90.00th=[ 7], 95.00th=[ 10],
| 99.00th=[ 22], 99.50th=[ 23], 99.90th=[ 26], 99.95th=[ 27],
| 99.99th=[ 103]
bw ( KiB/s): min=90528, max=444728, per=100.00%, avg=356839.00, stdev=6293.15, samples=1502
iops : min=22632, max=111182, avg=89209.75, stdev=1573.29, samples=1502
write: IOPS=89.3k, BW=349MiB/s (366MB/s)(16.0GiB/47011msec); 0 zone resets
slat (usec): min=14, max=96948, avg=106.71, stdev=186.90
clat (nsec): min=871, max=103573k, avg=5606631.51, stdev=3226988.42
lat (usec): min=27, max=103633, avg=5713.34, stdev=3283.39
clat percentiles (msec):
| 1.00th=[ 4], 5.00th=[ 5], 10.00th=[ 5], 20.00th=[ 5],
| 30.00th=[ 5], 40.00th=[ 5], 50.00th=[ 5], 60.00th=[ 6],
| 70.00th=[ 6], 80.00th=[ 6], 90.00th=[ 7], 95.00th=[ 10],
| 99.00th=[ 22], 99.50th=[ 23], 99.90th=[ 26], 99.95th=[ 26],
| 99.99th=[ 101]
bw ( KiB/s): min=91952, max=446992, per=100.00%, avg=357148.75, stdev=6305.30, samples=1502
iops : min=22988, max=111748, avg=89287.19, stdev=1576.32, samples=1502
lat (nsec) : 1000=0.01%
lat (usec) : 2=0.01%, 4=0.01%, 50=0.01%, 100=0.01%, 250=0.01%
lat (usec) : 500=0.01%, 750=0.01%, 1000=0.03%
lat (msec) : 2=0.05%, 4=4.13%, 10=91.11%, 20=2.64%, 50=2.01%
lat (msec) : 100=0.01%, 250=0.01%
cpu : usr=2.01%, sys=27.27%, ctx=14782061, majf=0, minf=193
IO depths : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=0.1%, 32=0.1%, >=64=100.0%
submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
complete : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.1%, >=64=0.0%
issued rwts: total=4192550,4196058,0,0 short=0,0,0,0 dropped=0,0,0,0
latency : target=0, window=0, percentile=100.00%, depth=64
Run status group 0 (all jobs):
READ: bw=348MiB/s (365MB/s), 348MiB/s-348MiB/s (365MB/s-365MB/s), io=16.0GiB (17.2GB), run=47011-47011msec
WRITE: bw=349MiB/s (366MB/s), 349MiB/s-349MiB/s (366MB/s-366MB/s), io=16.0GiB (17.2GB), run=47011-47011msec
# fio --name rw --rw rw --size 10G
rw: (g=0): rw=rw, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=psync, iodepth=1
fio-3.41
Starting 1 process
rw: Laying out IO file (1 file / 10240MiB)
Jobs: 1 (f=1): [M(1)][100.0%][r=1523MiB/s,w=1523MiB/s][r=390k,w=390k IOPS][eta 00m:00s]
rw: (groupid=0, jobs=1): err= 0: pid=4810: Thu Jan 29 15:36:09 2026
read: IOPS=418k, BW=1634MiB/s (1713MB/s)(5123MiB/3136msec)
clat (nsec): min=233, max=3887.3k, avg=1015.23, stdev=23344.54
lat (nsec): min=246, max=3887.3k, avg=1031.20, stdev=23344.62
clat percentiles (nsec):
| 1.00th=[ 253], 5.00th=[ 282], 10.00th=[ 338],
| 20.00th=[ 398], 30.00th=[ 414], 40.00th=[ 430],
| 50.00th=[ 450], 60.00th=[ 474], 70.00th=[ 524],
| 80.00th=[ 652], 90.00th=[ 788], 95.00th=[ 844],
| 99.00th=[ 1336], 99.50th=[ 1672], 99.90th=[ 8640],
| 99.95th=[ 56064], 99.99th=[1138688]
bw ( MiB/s): min= 1519, max= 1780, per=100.00%, avg=1640.79, stdev=106.94, samples=6
iops : min=389044, max=455704, avg=420041.67, stdev=27377.13, samples=6
write: IOPS=418k, BW=1632MiB/s (1711MB/s)(5117MiB/3136msec); 0 zone resets
clat (nsec): min=836, max=371633, avg=1106.25, stdev=684.75
lat (nsec): min=858, max=371656, avg=1128.75, stdev=688.75
clat percentiles (nsec):
| 1.00th=[ 868], 5.00th=[ 900], 10.00th=[ 908], 20.00th=[ 916],
| 30.00th=[ 940], 40.00th=[ 964], 50.00th=[ 996], 60.00th=[ 1032],
| 70.00th=[ 1096], 80.00th=[ 1192], 90.00th=[ 1400], 95.00th=[ 1624],
| 99.00th=[ 2288], 99.50th=[ 2672], 99.90th=[ 6496], 99.95th=[10432],
| 99.99th=[23680]
bw ( MiB/s): min= 1522, max= 1776, per=100.00%, avg=1639.30, stdev=106.03, samples=6
iops : min=389796, max=454896, avg=419661.33, stdev=27143.76, samples=6
lat (nsec) : 250=0.31%, 500=32.76%, 750=10.03%, 1000=32.17%
lat (usec) : 2=23.64%, 4=0.90%, 10=0.12%, 20=0.04%, 50=0.01%
lat (usec) : 100=0.01%, 250=0.01%, 500=0.01%, 750=0.01%, 1000=0.01%
lat (msec) : 2=0.01%, 4=0.01%
cpu : usr=17.70%, sys=81.63%, ctx=90, majf=0, minf=12
IO depths : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=0.0%
submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
complete : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
issued rwts: total=1311533,1309907,0,0 short=0,0,0,0 dropped=0,0,0,0
latency : target=0, window=0, percentile=100.00%, depth=1
Run status group 0 (all jobs):
READ: bw=1634MiB/s (1713MB/s), 1634MiB/s-1634MiB/s (1713MB/s-1713MB/s), io=5123MiB (5372MB), run=3136-3136msec
WRITE: bw=1632MiB/s (1711MB/s), 1632MiB/s-1632MiB/s (1711MB/s-1711MB/s), io=5117MiB (5365MB), run=3136-3136msec
EXT4 Fio Test
# fio --filename=fio-test --size=2G --direct=1 --rw=randrw --bs=4k --ioengine=libaio --iodepth=64 --numjobs=16 --group_reporting --name=iops-max-test
iops-max-test: (g=0): rw=randrw, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=libaio, iodepth=64
...
fio-3.41
Starting 16 processes
iops-max-test: Laying out IO file (1 file / 2048MiB)
Jobs: 16 (f=16): [m(16)][100.0%][r=2170MiB/s,w=2169MiB/s][r=556k,w=555k IOPS][eta 00m:00s]
iops-max-test: (groupid=0, jobs=16): err= 0: pid=5065: Thu Jan 29 15:37:29 2026
read: IOPS=550k, BW=2150MiB/s (2255MB/s)(16.0GiB/7617msec)
slat (nsec): min=917, max=626988, avg=3430.31, stdev=5314.23
clat (usec): min=29, max=11822, avg=815.61, stdev=529.37
lat (usec): min=30, max=11823, avg=819.04, stdev=529.85
clat percentiles (usec):
| 1.00th=[ 176], 5.00th=[ 269], 10.00th=[ 334], 20.00th=[ 437],
| 30.00th=[ 523], 40.00th=[ 603], 50.00th=[ 685], 60.00th=[ 791],
| 70.00th=[ 922], 80.00th=[ 1106], 90.00th=[ 1434], 95.00th=[ 1762],
| 99.00th=[ 2671], 99.50th=[ 3228], 99.90th=[ 5014], 99.95th=[ 5538],
| 99.99th=[ 7177]
bw ( MiB/s): min= 2023, max= 2227, per=100.00%, avg=2150.98, stdev= 3.16, samples=240
iops : min=518012, max=570160, avg=550649.47, stdev=810.10, samples=240
write: IOPS=551k, BW=2152MiB/s (2256MB/s)(16.0GiB/7617msec); 0 zone resets
slat (nsec): min=994, max=1225.1k, avg=3859.43, stdev=5879.37
clat (nsec): min=375, max=11896k, avg=1030567.39, stdev=561966.02
lat (usec): min=8, max=11898, avg=1034.43, stdev=562.38
clat percentiles (usec):
| 1.00th=[ 99], 5.00th=[ 347], 10.00th=[ 537], 20.00th=[ 660],
| 30.00th=[ 742], 40.00th=[ 832], 50.00th=[ 922], 60.00th=[ 1012],
| 70.00th=[ 1156], 80.00th=[ 1352], 90.00th=[ 1663], 95.00th=[ 1991],
| 99.00th=[ 2966], 99.50th=[ 3720], 99.90th=[ 5211], 99.95th=[ 5932],
| 99.99th=[ 7767]
bw ( MiB/s): min= 2026, max= 2229, per=100.00%, avg=2152.77, stdev= 3.22, samples=240
iops : min=518865, max=570792, avg=551109.67, stdev=824.81, samples=240
lat (nsec) : 500=0.01%
lat (usec) : 4=0.01%, 10=0.01%, 20=0.04%, 50=0.19%, 100=0.31%
lat (usec) : 250=3.02%, 500=14.54%, 750=25.47%, 1000=23.11%
lat (msec) : 2=29.29%, 4=3.69%, 10=0.34%, 20=0.01%
cpu : usr=9.44%, sys=28.00%, ctx=4630783, majf=0, minf=153
IO depths : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=0.1%, 32=0.1%, >=64=100.0%
submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
complete : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.1%, >=64=0.0%
issued rwts: total=4192550,4196058,0,0 short=0,0,0,0 dropped=0,0,0,0
latency : target=0, window=0, percentile=100.00%, depth=64
Run status group 0 (all jobs):
READ: bw=2150MiB/s (2255MB/s), 2150MiB/s-2150MiB/s (2255MB/s-2255MB/s), io=16.0GiB (17.2GB), run=7617-7617msec
WRITE: bw=2152MiB/s (2256MB/s), 2152MiB/s-2152MiB/s (2256MB/s-2256MB/s), io=16.0GiB (17.2GB), run=7617-7617msec
Disk stats (read/write):
nvme1n1: ios=4129380/4145271, sectors=33035040/36253288, merge=0/6, ticks=3275406/4131695, in_queue=7407102, util=89.51%
# fio --name rw --rw rw --size 10G
rw: (g=0): rw=rw, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=psync, iodepth=1
fio-3.41
Starting 1 process
rw: Laying out IO file (1 file / 10240MiB)
Jobs: 1 (f=1): [M(1)][-.-%][r=1878MiB/s,w=1876MiB/s][r=481k,w=480k IOPS][eta 00m:00s]
rw: (groupid=0, jobs=1): err= 0: pid=5125: Thu Jan 29 15:38:03 2026
read: IOPS=488k, BW=1907MiB/s (2000MB/s)(5123MiB/2686msec)
clat (nsec): min=231, max=4875.7k, avg=1022.86, stdev=26230.76
lat (nsec): min=247, max=4875.8k, avg=1039.04, stdev=26230.81
clat percentiles (nsec):
| 1.00th=[ 258], 5.00th=[ 286], 10.00th=[ 366], 20.00th=[ 390],
| 30.00th=[ 402], 40.00th=[ 414], 50.00th=[ 422], 60.00th=[ 434],
| 70.00th=[ 446], 80.00th=[ 466], 90.00th=[ 532], 95.00th=[ 716],
| 99.00th=[ 16768], 99.50th=[ 18304], 99.90th=[ 34048], 99.95th=[ 54528],
| 99.99th=[790528]
bw ( MiB/s): min= 1640, max= 2250, per=100.00%, avg=1930.54, stdev=269.78, samples=5
iops : min=420064, max=576100, avg=494218.80, stdev=69063.19, samples=5
write: IOPS=488k, BW=1905MiB/s (1998MB/s)(5117MiB/2686msec); 0 zone resets
clat (nsec): min=441, max=457616, avg=778.90, stdev=1412.63
lat (nsec): min=463, max=457637, avg=800.30, stdev=1413.59
clat percentiles (nsec):
| 1.00th=[ 556], 5.00th=[ 572], 10.00th=[ 580], 20.00th=[ 596],
| 30.00th=[ 612], 40.00th=[ 628], 50.00th=[ 644], 60.00th=[ 668],
| 70.00th=[ 692], 80.00th=[ 780], 90.00th=[ 972], 95.00th=[ 1064],
| 99.00th=[ 3472], 99.50th=[ 3792], 99.90th=[ 5472], 99.95th=[13632],
| 99.99th=[59136]
bw ( MiB/s): min= 1643, max= 2240, per=100.00%, avg=1928.76, stdev=267.83, samples=5
iops : min=420716, max=573634, avg=493763.20, stdev=68563.63, samples=5
lat (nsec) : 250=0.22%, 500=43.66%, 750=43.34%, 1000=7.62%
lat (usec) : 2=3.29%, 4=0.93%, 10=0.16%, 20=0.62%, 50=0.12%
lat (usec) : 100=0.02%, 250=0.01%, 500=0.01%, 750=0.01%, 1000=0.01%
lat (msec) : 2=0.01%, 4=0.01%, 10=0.01%
cpu : usr=19.89%, sys=63.72%, ctx=3046, majf=0, minf=10
IO depths : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=0.0%
submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
complete : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
issued rwts: total=1311533,1309907,0,0 short=0,0,0,0 dropped=0,0,0,0
latency : target=0, window=0, percentile=100.00%, depth=1
Run status group 0 (all jobs):
READ: bw=1907MiB/s (2000MB/s), 1907MiB/s-1907MiB/s (2000MB/s-2000MB/s), io=5123MiB (5372MB), run=2686-2686msec
WRITE: bw=1905MiB/s (1998MB/s), 1905MiB/s-1905MiB/s (1998MB/s-1998MB/s), io=5117MiB (5365MB), run=2686-2686msec
Disk stats (read/write):
nvme1n1: ios=37690/20969, sectors=9636664/5366304, merge=0/2, ticks=4435/37122, in_queue=41557, util=54.00%
Si, podemos decir que es un poco escueto, pero es el mismo comando en 2 sistemas de ficheros distintos con algunas diferencias.
Todo esto sin ningún tipo de tuning,
El problema viene de que tengo un sistema en el que monte luks2 y btrfs por encima y el rendimiento es bastante peor si probamos con FIO, luego en el día a día no se nota, ,pero fue en un samasung pro 580, luego hice las pruebas en un P510 de crucial sin luks y también se ha notado.
¿ Entonces por que uso btrfs si es más lento que ext4 ?
No tengo ninguna necesidad, pero tal vez un día vaya a usar los snapshots antes de actualizar y en el día a día no se nota ninguna diferencia real.
Y arrancando el sistema no se si se note diferencia, pero todo es probar.