Matt Pursley
2013-Apr-16 16:56 UTC
One random read streaming is fast (~1200MB/s), but two or more are slower (~750MB/s)?
Hi All,
I have an LSI HBA card (LSI SAS 9207-8i) with 12 7200rpm SAS drives
attached. When it''s formated with mdraid6+ext4 I get about 1200MB/s
for multiple streaming random reads with iozone. With btrfs in
3.9.0-rc4 I can also get about 1200MB/s, but only with one stream at a
time.
As soon as I add a second (or more), the speed will drop to about
750MB/s. If I add more streams (10, 20, etc), the total throughput
stays at around 750MB/s. I only see the full 1200MB/s in btrfs when
I''m running a single read at a time (e.g. sequential reads with dd,
random reads with iozone, etc).
This feel like a bug or mis-configuration on my system. As if can
read at the full speed, but just only with one stream running at a
time. The options I have tried varying are "-l 64k" with mkfs.btrfs,
and "-o thread_pool=16" when mounting. But, neither of those options
seem to change the behaviour.
Anyone know any reasons why I would see the speed drop when going from
one to more then one stream at a time with btrfs raid6? We would like
to use btrfs (mostly for snapshots), but we do need to get the full
1200MB/s streaming speeds too..
Thanks,
Matt
___
Here''s some example output..
Single thread = ~1.1GB/s
_____
kura1 persist # sysctl vm.drop_caches=1 ; dd if=/dev/zero
of=/var/data/persist/testfile bs=640k count=20000
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 7.14139 s, 1.8 GB/s
kura1 persist # sysctl vm.drop_caches=1 ; dd of=/dev/null
if=/var/data/persist/testfile bs=640k
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 11.2666 s, 1.2 GB/s
kura1 persist # sysctl vm.drop_caches=1 ; dd of=/dev/null
if=/var/data/persist/testfile bs=640k
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 11.5005 s, 1.1 GB/s
____
1 thread = ~1000MB/s ...
___
kura1 scripts # sysctl vm.drop_caches=1 ; for j in {1..1} ; do dd
of=/dev/null if=/var/data/persist/testfile_$j bs=640k ; done
vm.drop_caches = 1
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 6.52018 s, 1.0 GB/s
kura1 scripts # sysctl vm.drop_caches=1 ; for j in {1..1} ; do dd
of=/dev/null if=/var/data/persist/testfile_$j bs=640k ; done
vm.drop_caches = 1
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 6.55731 s, 999 MB/s
___
2 threads = ~750MB/s combined...
___
# sysctl vm.drop_caches=1 ; for j in {1..2} ; do dd of=/dev/null
if=/var/data/persist/testfile_$j bs=640k & done
vm.drop_caches = 1
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 17.5068 s, 374 MB/s
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 17.7599 s, 369 MB/s
___
20 threads = ~750MB/s combined...
___
# sysctl vm.drop_caches=1 ; for j in {1..20} ; do dd of=/dev/null
if=/var/data/persist/testfile_$j bs=640k & done
vm.drop_caches = 1
kura1 scripts # 10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 168.223 s, 39.0 MB/s
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 168.275 s, 38.9 MB/s
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 169.466 s, 38.7 MB/s
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 169.606 s, 38.6 MB/s
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 170.503 s, 38.4 MB/s
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 170.629 s, 38.4 MB/s
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 170.633 s, 38.4 MB/s
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 170.744 s, 38.4 MB/s
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 170.844 s, 38.4 MB/s
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 170.896 s, 38.3 MB/s
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 171.027 s, 38.3 MB/s
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 171.135 s, 38.3 MB/s
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 171.389 s, 38.2 MB/s
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 171.414 s, 38.2 MB/s
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 171.674 s, 38.2 MB/s
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 171.897 s, 38.1 MB/s
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 171.956 s, 38.1 MB/s
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 171.995 s, 38.1 MB/s
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 172.044 s, 38.1 MB/s
10000+0 records in
10000+0 records out
6553600000 bytes (6.6 GB) copied, 172.08 s, 38.1 MB/s
____
### Similar results with random reads in iozone...
1 thread = ~1000MB/s
_____
kura1 scripts # for j in {1..1} ; do sysctl vm.drop_caches=1 ; iozone
-f /var/data/10GBfolders/folder$j/iozone.DUMMY.1 -c -M -r 5120k -s 2g
-i 1 -w -+A 1 | tail -n 5 & done
vm.drop_caches = 1
[1] 22298
kura1 scripts #
random random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 1077376 7288014
iozone test complete.
____
2 threads = ~750 MB/s combined...
___
# for j in {1..2} ; do sysctl vm.drop_caches=1 ; iozone -f
/var/data/10GBfolders/folder$j/iozone.DUMMY.1 -c -M -r 5120k -s 2g -i
1 -w -+A 1 | tail -n 5 & done
vm.drop_caches = 1
[1] 22302
vm.drop_caches = 1
[2] 22305
kura1 scripts #
random random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 368864 5090095
iozone test complete.
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 366834 5105457
iozone test complete.
20 threads = ~750MB/s combined...
___
# for j in {1..20} ; do sysctl vm.drop_caches=1 ; iozone -f
/var/data/10GBfolders/folder$j/iozone.DUMMY.1 -c -M -r 5120k -s 2g -i
1 -w -+A 1 | tail -n 5 & done
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 40424 6459500
iozone test complete.
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 39678 5749776
iozone test complete.
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 39548 5417189
iozone test complete.
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 38988 5924904
iozone test complete.
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 38484 1963969
iozone test complete.
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 38556 1793398
iozone test complete.
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 38610 1343518
iozone test complete.
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 38346 1394609
iozone test complete.
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 38367 1163930
iozone test complete.
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 38375 1143491
iozone test complete.
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 38647 1046416
iozone test complete.
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 38180 1115287
iozone test complete.
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 38086 1192537
iozone test complete.
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 38356 1120244
iozone test complete.
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 38293 1138119
iozone test complete.
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 37966 1273741
iozone test complete.
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 38059 1201688
iozone test complete.
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 37947 1243573
iozone test complete.
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 37965 1245834
iozone test complete.
random
random bkwd record stride
KB reclen write rewrite read reread read
write read rewrite read fwrite frewrite fread freread
2097152 5120 37840 1354806
iozone test complete.
___
### Typical dstat output during multi-thread read running and then
finish and go idle...
___
----total-cpu-usage---- -dsk/total- -net/total- ---paging-- ---system--
usr sys idl wai hiq siq| read writ| recv send| in out | int csw
0 10 28 62 0 0| 716M 0 | 582B 870B| 0 0 |4398 16k
0 12 28 59 0 0| 728M 0 | 454B 982B| 0 0 |4665 16k
0 12 25 63 0 0| 761M 0 | 454B 1112B| 0 0 |4661 16k
0 11 22 66 0 0| 719M 0 | 390B 742B| 0 0 |4519 16k
0 13 21 65 0 0| 741M 0 | 524B 1036B| 0 0 |4706 16k
0 17 19 63 0 0| 706M 0 |3302B 3558B| 0 0 |4638 15k
0 16 17 67 0 0| 721M 0 | 16k 15k| 0 0 |5002 17k
2 72 7 19 0 0| 514M 0 | 454B 486B| 0 0 |4174 8591
3 97 0 0 0 0| 0 0 | 788B 2884B| 0 0 |1280 380
1 38 61 0 0 0| 0 0 |1428B 7460B| 0 0 | 888 346
0 0 100 0 0 0| 0 0 | 582B 678B| 0 0 | 92 106
0 0 100 0 0 0| 0 0 |1606B 1766B| 0 0 | 66 59
0 0 100 0 0 0| 0 4096B| 390B 742B| 0 0 | 90 112
0 0 100 0 0 0| 0 0 | 454B 486B| 0 0 | 45 65
0 0 100 0 0 0| 0 0 | 454B 614B| 0 0 | 56 77
___
### Some system info...
____
## Kernel = 3.9.0-rc4
# uname -a
Linux server 3.9.0-rc4 #4 SMP Fri Apr 5 00:58:28 UTC 2013 x86_64
Intel(R) Xeon(R) CPU E5-2630 0 @ 2.30GHz GenuineIntel GNU/Linux
# grep MemTotal /proc/meminfo
MemTotal: 65975896 kB
___
## 12 2.3 GHz Xeon cores...
kura1 scripts # head -n 26 /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 45
model name : Intel(R) Xeon(R) CPU E5-2630 0 @ 2.30GHz
stepping : 6
microcode : 0x616
cpu MHz : 2301.000
cache size : 15360 KB
physical id : 0
siblings : 12
core id : 0
cpu cores : 6
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 13
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx
pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl
xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor
ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm pcid dca sse4_1 sse4_2
x2apic popcnt tsc_deadline_timer aes xsave avx lahf_lm ida arat epb
xsaveopt pln pts dtherm tpr_shadow vnmi flexpriority ept vpid
bogomips : 4600.26
clflush size : 64
cache_alignment : 64
address sizes : 46 bits physical, 48 bits virtual
power management:
___
## Asus Z9PA-U8 MB
# dmidecode --type 1
# dmidecode 2.11
SMBIOS 2.7 present.
Handle 0x0001, DMI type 1, 27 bytes
System Information
Manufacturer: ASUSTeK COMPUTER INC.
Product Name: Z9PA-U8 Series
Version: 1.0X
Serial Number: To be filled by O.E.M.
UUID: 598C1800-5BCB-11D9-8F58-3085A9A7CBC7
Wake-up Type: Power Switch
SKU Number: SKU
Family: To be filled by O.E.M.
____
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Sander
2013-Apr-17 06:55 UTC
Re: One random read streaming is fast (~1200MB/s), but two or more are slower (~750MB/s)?
Matt Pursley wrote (ao):> I have an LSI HBA card (LSI SAS 9207-8i) with 12 7200rpm SAS drives > attached. When it''s formated with mdraid6+ext4 I get about 1200MB/s > for multiple streaming random reads with iozone. With btrfs in > 3.9.0-rc4 I can also get about 1200MB/s, but only with one stream at a > time.Just curious, is that btrfs on top of mdraid6, or is this experimental btrfs raid6 without md? -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Matt Pursley
2013-Apr-17 17:30 UTC
Re: One random read streaming is fast (~1200MB/s), but two or more are slower (~750MB/s)?
On Tue, Apr 16, 2013 at 11:55 PM, Sander <sander@humilis.net> wrote:> Matt Pursley wrote (ao): >> I have an LSI HBA card (LSI SAS 9207-8i) with 12 7200rpm SAS drives >> attached. When it''s formated with mdraid6+ext4 I get about 1200MB/s >> for multiple streaming random reads with iozone. With btrfs in >> 3.9.0-rc4 I can also get about 1200MB/s, but only with one stream at a >> time. > > Just curious, is that btrfs on top of mdraid6, or is this experimental > btrfs raid6 without md?This is the "experimental btrfs raid6 without md". But, I did do a "mdraid6 with btrfs" test last night... and with that setup I only get the ~750MB/s result.. even with just one thread/stream... I will flip the system back to "btrfsraid6+btrfs" today to verify that I still get the full 1200MB/s with one stream/thread and ~750MB/s with two or more streams/threads with that setup... Thanks, Matt ___ mdraid6+btrfs_64GBRam_80files # sysctl vm.drop_caches=1 ; dd of=/dev/null if=/var/data/persist/testfile bs=640k vm.drop_caches = 1 20000+0 records in 20000+0 records out 13107200000 bytes (13 GB) copied, 18.2109 s, 720 MB/s ___ -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Matt Pursley
2013-Apr-18 01:50 UTC
Re: One random read streaming is fast (~1200MB/s), but two or more are slower (~750MB/s)?
Hey All,
Here are the results of making and reading back a 13GB file on
"mdraid6 + ext4", "mdraid6 + btrfs", and "btrfsraid6 +
btrfs".
Seems to show that:
1) "mdraid6 + ext4" can do ~1100 MB/s for these sequential reads with
either one or two files at once.
2) "btrfsraid6 + btrfs" can do ~1100 MB/s for sequential reads with
one file at a time, but only ~750 MB/s with two (or more).
3) "mdraid6 + btrfs" can only do ~750 MB/s for these sequential reads
with either one or two files at once.
So, seems like the speed drop is related more to the btrfs files
system, then the experimental raid.
Although it is interesting that btrfs can only do the full ~1100 MB/s
with a single file on the btrfsraid6, but not mdraid6.
Anyway, just some more info and reproducible results.
I have also opened a ticket in bugzilla.kernel.org for this issue here...
https://bugzilla.kernel.org/show_bug.cgi?id=56771
Thanks,
Matt
___ mdraid6 + ext4 ___
kura1 / # mount | grep -i /var/data
/dev/md0 on /var/data type ext4 (rw)
kura1 / # cat /proc/mdstat
Personalities : [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
[linear] [multipath]
md0 : active raid6 sdm[11] sdl[10] sdk[9] sdj[8] sdi[7] sdh[6] sdg[5]
sdf[4] sde[3] sdd[2] sdc[1] sdb[0]
29302650880 blocks super 1.2 level 6, 512k chunk, algorithm 2
[12/12] [UUUUUUUUUUUU]
[>....................] resync = 0.0% (2731520/2930265088)
finish=47268.1min speed=1031K/sec
unused devices: <none>
## Create two 13GB testfiles...
kura1 / # sysctl vm.drop_caches=1 ; dd if=/dev/zero
of=/var/data/persist/testfile1 bs=640k count=20000 conv=fdatasync
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 47.27 s, 277 MB/s
kura1 / # sysctl vm.drop_caches=1 ; dd if=/dev/zero
of=/var/data/persist/testfile2 bs=640k count=20000 conv=fdatasync
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 47.0237 s, 279 MB/s
## Read back one testfile... ~1300 MB/s
kura1 / # sysctl vm.drop_caches=1 ; dd of=/dev/null
if=/var/data/persist/testfile1 bs=640k
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 10.3469 s, 1.3 GB/s
kura1 / # sysctl vm.drop_caches=1 ; dd of=/dev/null
if=/var/data/persist/testfile1 bs=640k
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 10.0073 s, 1.3 GB/s
kura1 / # sysctl vm.drop_caches=1 ; dd of=/dev/null
if=/var/data/persist/testfile1 bs=640k
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 10.69 s, 1.2 GB/s
## Read back the two testfiles at the same time.. ~1100MB/s
kura1 / # (sysctl vm.drop_caches=1 ; dd of=/dev/null
if=/var/data/persist/testfile1 bs=640k) & (sysctl vm.drop_caches=1 ;
dd of=//dev/null if=/var/data/persist/testfile2 bs=640k) & wait
vm.drop_caches = 1
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 24.4988 s, 535 MB/s
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 24.591 s, 533 MB/s
kura1 / # (sysctl vm.drop_caches=1 ; dd of=/dev/null
if=/var/data/persist/testfile1 bs=640k) & (sysctl vm.drop_caches=1 ;
dd of=//dev/null if=/var/data/persist/testfile2 bs=640k) & wait
vm.drop_caches = 1
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 24.7013 s, 531 MB/s
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 24.7016 s, 531 MB/s
kura1 / # (sysctl vm.drop_caches=1 ; dd of=/dev/null
if=/var/data/persist/testfile1 bs=640k) & (sysctl vm.drop_caches=1 ;
dd of=//dev/null if=/var/data/persist/testfile2 bs=640k) & wait
vm.drop_caches = 1
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 24.5512 s, 534 MB/s
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 24.8276 s, 528 MB/s
________________________________
___ mdraid6 + btrfs _______________
kura1 ~ # mount | grep -i /var/data
/dev/md0 on /var/data type btrfs (rw,noatime)
kura1 ~ # cat /proc/mdstat
Personalities : [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
[linear] [multipath]
md0 : active raid6 sdm[11] sdl[10] sdk[9] sdj[8] sdi[7] sdh[6] sdg[5]
sdf[4] sde[3] sdd[2] sdc[1] sdb[0]
29302650880 blocks super 1.2 level 6, 512k chunk, algorithm 2
[12/12] [UUUUUUUUUUUU]
[>....................] resync = 0.0% (1917184/2930265088)
finish=44415.7min speed=1098K/sec
unused devices: <none>
kura1 ~ # btrfs filesystem show
failed to open /dev/sr0: No medium found
Label: none uuid: 5eb756b5-03a1-4d06-8e91-0f683a763a88
Total devices 1 FS bytes used 448.00KB
devid 1 size 27.29TB used 2.04GB path /dev/md0
Label: none uuid: 4546715c-8948-42b3-b529-a1c9cd175c2e
Total devices 12 FS bytes used 80.74GB
devid 12 size 2.73TB used 9.35GB path /dev/sdm
devid 11 size 2.73TB used 9.35GB path /dev/sdl
devid 10 size 2.73TB used 9.35GB path /dev/sdk
devid 9 size 2.73TB used 9.35GB path /dev/sdj
devid 8 size 2.73TB used 9.35GB path /dev/sdi
devid 7 size 2.73TB used 9.35GB path /dev/sdh
devid 6 size 2.73TB used 9.35GB path /dev/sdg
devid 5 size 2.73TB used 9.35GB path /dev/sdf
devid 4 size 2.73TB used 9.35GB path /dev/sde
devid 3 size 2.73TB used 9.35GB path /dev/sdd
devid 2 size 2.73TB used 9.35GB path /dev/sdc
devid 1 size 2.73TB used 9.37GB path /dev/sdb
Btrfs v0.20-rc1-253-g7854c8b
## Create two 13GB testfiles...
kura1 ~ # sysctl vm.drop_caches=1 ; dd if=/dev/zero
of=/var/data/persist/testfile1 bs=640k count=20000 conv=fdatasync
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 34.2789 s, 382 MB/s
kura1 ~ # sysctl vm.drop_caches=1 ; dd if=/dev/zero
of=/var/data/persist/testfile2 bs=640k count=20000 conv=fdatasync
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 43.2937 s, 303 MB/s
## Read back one testfile... ~750 MB/s
kura1 ~ # sysctl vm.drop_caches=1 ; dd of=/dev/null
if=/var/data/persist/testfile1 bs=640k
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 16.7785 s, 781 MB/s
kura1 ~ # sysctl vm.drop_caches=1 ; dd of=/dev/null
if=/var/data/persist/testfile1 bs=640k
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 18.1361 s, 723 MB/s
kura1 ~ # sysctl vm.drop_caches=1 ; dd of=/dev/null
if=/var/data/persist/testfile1 bs=640k
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 19.1985 s, 683 MB/s
## Read back the two testfiles at the same time.. ~750MB/s
kura1 ~ # (sysctl vm.drop_caches=1 ; dd of=/dev/null
if=/var/data/persist/testfile1 bs=640k) & (sysctl vm.drop_caches=1 ;
dd of=//dev/null if=/var/data/persist/testfile2 bs=640k) & wait
vm.drop_caches = 1
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 30.8396 s, 425 MB/s
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 35.5478 s, 369 MB/s
kura1 ~ # (sysctl vm.drop_caches=1 ; dd of=/dev/null
if=/var/data/persist/testfile1 bs=640k) & (sysctl vm.drop_caches=1 ;
dd of=//dev/null if=/var/data/persist/testfile2 bs=640k) & wait
vm.drop_caches = 1
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 34.6504 s, 378 MB/s
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 35.7795 s, 366 MB/s
kura1 ~ # (sysctl vm.drop_caches=1 ; dd of=/dev/null
if=/var/data/persist/testfile1 bs=640k) & (sysctl vm.drop_caches=1 ;
dd of=//dev/null if=/var/data/persist/testfile2 bs=640k) & wait
vm.drop_caches = 1
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 36.9101 s, 355 MB/s
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 37.7395 s, 347 MB/s
________________________
___ btrfsraid6 + btrfs ___
kura1 ~ # mount | grep -i /var/data
/dev/sdl on /var/data type btrfs (rw,noatime)
kura1 ~ # btrfs filesystem show
failed to open /dev/sr0: No medium found
Label: none uuid: 4546715c-8948-42b3-b529-a1c9cd175c2e
Total devices 12 FS bytes used 80.74GB
devid 12 size 2.73TB used 9.35GB path /dev/sdm
devid 11 size 2.73TB used 9.35GB path /dev/sdl
devid 10 size 2.73TB used 9.35GB path /dev/sdk
devid 9 size 2.73TB used 9.35GB path /dev/sdj
devid 8 size 2.73TB used 9.35GB path /dev/sdi
devid 7 size 2.73TB used 9.35GB path /dev/sdh
devid 6 size 2.73TB used 9.35GB path /dev/sdg
devid 5 size 2.73TB used 9.35GB path /dev/sdf
devid 4 size 2.73TB used 9.35GB path /dev/sde
devid 3 size 2.73TB used 9.35GB path /dev/sdd
devid 2 size 2.73TB used 9.35GB path /dev/sdc
devid 1 size 2.73TB used 9.37GB path /dev/sdb
Btrfs v0.20-rc1-253-g7854c8b
## Create two 13GB testfiles...
kura1 data # sysctl vm.drop_caches=1 ; dd if=/dev/zero
of=/var/data/persist/testfile2 bs=640k count=20000 conv=fdatasync
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 21.5018 s, 610 MB/s
kura1 data # sysctl vm.drop_caches=1 ; dd if=/dev/zero
of=/var/data/persist/testfile1 bs=640k count=20000 conv=fdatasync
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 21.3389 s, 614 MB/s
## Read back one testfile... ~1100 MB/s
kura1 data # sysctl vm.drop_caches=1 ; dd of=/dev/null
if=/var/data/persist/testfile1 bs=640k
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 11.8312 s, 1.1 GB/s
kura1 data # sysctl vm.drop_caches=1 ; dd of=/dev/null
if=/var/data/persist/testfile1 bs=640k
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 11.7888 s, 1.1 GB/s
kura1 data # sysctl vm.drop_caches=1 ; dd of=/dev/null
if=/var/data/persist/testfile1 bs=640k
vm.drop_caches = 1
20000+0 records in
20000+0 records out
20000+0 records out
13107200000 bytes (13 GB) copied, 41.4113 s, 317 MB/s
kura1 data # (sysctl vm.drop_caches=1 ; dd of=/dev/null
if=/var/data/persist/testfile1 bs=640k) & (sysctl vm.drop_caches=1 ;
dd of=/dev/null if=/var/data/persist/testfile2 bs=640k) & wait
[1] 19482
[2] 19483
vm.drop_caches = 1
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 36.0124 s, 364 MB/s
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 36.2298 s, 362 MB/s
kura1 data # (sysctl vm.drop_caches=1 ; dd of=/dev/null
if=/var/data/persist/testfile1 bs=640k) & (sysctl vm.drop_caches=1 ;
dd of=/dev/null if=/var/data/persist/testfile2 bs=640k) & wait
[1] 19500
[2] 19501
vm.drop_caches = 1
vm.drop_caches = 1
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 35.4703 s, 370 MB/s
20000+0 records in
20000+0 records out
13107200000 bytes (13 GB) copied, 35.7789 s, 366 MB/s
[1]- Done ( sysctl vm.drop_caches=1; dd
of=/dev/null if=/var/data/persist/testfile1 bs=640k )
[2]+ Done ( sysctl vm.drop_caches=1; dd
of=/dev/null if=/var/data/persist/testfile2 bs=640k )
_____
On Wed, Apr 17, 2013 at 10:30 AM, Matt Pursley <mpursley@gmail.com>
wrote:> On Tue, Apr 16, 2013 at 11:55 PM, Sander <sander@humilis.net> wrote:
>> Matt Pursley wrote (ao):
>>> I have an LSI HBA card (LSI SAS 9207-8i) with 12 7200rpm SAS drives
>>> attached. When it''s formated with mdraid6+ext4 I get
about 1200MB/s
>>> for multiple streaming random reads with iozone. With btrfs in
>>> 3.9.0-rc4 I can also get about 1200MB/s, but only with one stream
at a
>>> time.
>>
>> Just curious, is that btrfs on top of mdraid6, or is this experimental
>> btrfs raid6 without md?
>
>
>
> This is the "experimental btrfs raid6 without md".
>
> But, I did do a "mdraid6 with btrfs" test last night... and with
that
> setup I only get the ~750MB/s result.. even with just one
> thread/stream...
>
> I will flip the system back to "btrfsraid6+btrfs" today to verify
that
> I still get the full 1200MB/s with one stream/thread and ~750MB/s with
> two or more streams/threads with that setup...
>
>
> Thanks,
> Matt
>
>
>
> ___
> mdraid6+btrfs_64GBRam_80files # sysctl vm.drop_caches=1 ; dd
> of=/dev/null if=/var/data/persist/testfile bs=640k
> vm.drop_caches = 1
> 20000+0 records in
> 20000+0 records out
> 13107200000 bytes (13 GB) copied, 18.2109 s, 720 MB/s
> ___
--
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Josef Bacik
2013-Apr-18 21:58 UTC
Re: One random read streaming is fast (~1200MB/s), but two or more are slower (~750MB/s)?
On Wed, Apr 17, 2013 at 07:50:09PM -0600, Matt Pursley wrote:> Hey All, > > Here are the results of making and reading back a 13GB file on > "mdraid6 + ext4", "mdraid6 + btrfs", and "btrfsraid6 + btrfs". > > Seems to show that: > 1) "mdraid6 + ext4" can do ~1100 MB/s for these sequential reads with > either one or two files at once. > 2) "btrfsraid6 + btrfs" can do ~1100 MB/s for sequential reads with > one file at a time, but only ~750 MB/s with two (or more). > 3) "mdraid6 + btrfs" can only do ~750 MB/s for these sequential reads > with either one or two files at once. > > > So, seems like the speed drop is related more to the btrfs files > system, then the experimental raid. > Although it is interesting that btrfs can only do the full ~1100 MB/s > with a single file on the btrfsraid6, but not mdraid6. > > > Anyway, just some more info and reproducible results. > > I have also opened a ticket in bugzilla.kernel.org for this issue here... > https://bugzilla.kernel.org/show_bug.cgi?id=56771 >This is strange, and I can''t see any reason why this would happen. I''ll try and reproduce next week when I''m back from LSF. Thanks, Josef -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Matt Pursley
2013-Apr-25 19:52 UTC
Re: One random read streaming is fast (~1200MB/s), but two or more are slower (~750MB/s)?
Hey Josef, Were you able to look into this any further? It''s still pretty reproducible on my machine... Thanks, Matt On Thu, Apr 18, 2013 at 2:58 PM, Josef Bacik <jbacik@fusionio.com> wrote:> This is strange, and I can''t see any reason why this would happen. I''ll try and > reproduce next week when I''m back from LSF. Thanks, > > Josef-- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Josef Bacik
2013-Apr-25 20:39 UTC
Re: One random read streaming is fast (~1200MB/s), but two or more are slower (~750MB/s)?
On Thu, Apr 25, 2013 at 01:52:44PM -0600, Matt Pursley wrote:> Hey Josef, > > Were you able to look into this any further? > It''s still pretty reproducible on my machine... >Nope I''ve been tracking down random problems, I''ll try it now. Thanks, Josef -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Matt Pursley
2013-Apr-25 21:01 UTC
Re: One random read streaming is fast (~1200MB/s), but two or more are slower (~750MB/s)?
Ok, awesome, let me know how it goes.. I don''t have the raid formatted to btrfs right now, but I could probably do that in about 30 minutes or so. Thanks Josef, Matt On Thu, Apr 25, 2013 at 1:39 PM, Josef Bacik <jbacik@fusionio.com> wrote:> On Thu, Apr 25, 2013 at 01:52:44PM -0600, Matt Pursley wrote: >> Hey Josef, >> >> Were you able to look into this any further? >> It''s still pretty reproducible on my machine... >> > > Nope I''ve been tracking down random problems, I''ll try it now. Thanks, > > Josef-- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Josef Bacik
2013-Apr-25 21:10 UTC
Re: One random read streaming is fast (~1200MB/s), but two or more are slower (~750MB/s)?
On Thu, Apr 25, 2013 at 03:01:18PM -0600, Matt Pursley wrote:> Ok, awesome, let me know how it goes.. I don''t have the raid > formatted to btrfs right now, but I could probably do that in about 30 > minutes or so. >Huh so I''m getting the full bandwidth, 120 mb/s with one thread and 60 mb/s with two threads. These are just cheap sata drives tho, I''ll try and dig up a box with 3 fusion cards for something a little closer to the speeds you are seeing and see if that makes a difference. Thanks, Josef -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Matt Pursley
2013-Apr-26 23:21 UTC
Re: One random read streaming is fast (~1200MB/s), but two or more are slower (~750MB/s)?
Hey Josef, Thanks for looking into this further! That is about the same results that I was seeing, though I didn''t test it with just one drive.. only with all 12 drives in my jbod. I will do a test with just one disk, and see if I also get the same results. Let me know if you also see the same results with multiple drives in your raid... Thanks, Matt On Thu, Apr 25, 2013 at 2:10 PM, Josef Bacik <jbacik@fusionio.com> wrote:> On Thu, Apr 25, 2013 at 03:01:18PM -0600, Matt Pursley wrote: >> Ok, awesome, let me know how it goes.. I don''t have the raid >> formatted to btrfs right now, but I could probably do that in about 30 >> minutes or so. >> > > Huh so I''m getting the full bandwidth, 120 mb/s with one thread and 60 mb/s with > two threads. These are just cheap sata drives tho, I''ll try and dig up a box > with 3 fusion cards for something a little closer to the speeds you are seeing > and see if that makes a difference. Thanks, > > Josef-- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Matt Pursley
2013-May-02 18:51 UTC
Re: One random read streaming is fast (~1200MB/s), but two or more are slower (~750MB/s)?
Hey Josef,
Were you able to try this multi-thread test on any more drives?
I did a test with 12, 6, 3, and 1 drive. And, it looks like I see the
multi-thread speed reduces, as the number of drives in the raid goes
up.
Like this:
- 50% speed reduction with 2 threads on 12 drives
- 25% speed reduction with 2 threads on 6 drives
- 10% speed reduction with 2 threads on 3 drives
- 5% speed reduction with 2 threads on 1 drive
I only have 12 slots on my HBA card, but I wonder if 24 drives would
reduce the speed to 25% with 2 threads?
Matt
make btrfs fs...
___
12 drives...
mkfs.btrfs -f -d raid6 /dev/sda /dev/sdb /dev/sdc /dev/sdd /dev/sde
/dev/sdf /dev/sdg /dev/sdh /dev/sdi /dev/sdj /dev/sdk /dev/sdl
6 drives...
mkfs.btrfs -f -d raid6 /dev/sda /dev/sdb /dev/sdc /dev/sdd /dev/sde /dev/sdf
3 drives...
mkfs.btrfs -f -d raid5 /dev/sda /dev/sdb /dev/sdc
1 drive...
mkfs.btrfs -f /dev/sda
mount /dev/sda /tmp/btrfs_test/
___
make zero files...
___
kura1 ~ # for j in {1..2} ; do dd if=/dev/zero
of=/tmp/btrfs_test/testfile_bs1m_size10GB_${j} bs=1M count=10000
conv=fdatasync & done
___
==================
btrfs raid6 on 12 drives with 2 threads = ~650MB/s
___
kura1 btrfs_test # sysctl vm.drop_caches=1 ; for j in {1..2} ; do dd
of=/dev/null if=/tmp/btrfs_test/testfile_bs1m_size10GB_${j} bs=1M &
done
vm.drop_caches = 1
10485760000 bytes (10 GB) copied, 31.0431 s, 338 MB/s
10485760000 bytes (10 GB) copied, 31.2235 s, 336 MB/s
kura1 btrfs_test # sysctl vm.drop_caches=1 ; for j in {1..2} ; do dd
of=/dev/null if=/tmp/btrfs_test/testfile_bs1m_size10GB_${j} bs=1M &
done
10485760000 bytes (10 GB) copied, 29.869 s, 351 MB/s
10485760000 bytes (10 GB) copied, 30.5561 s, 343 MB/s
___
btrfs raid6 on 12 drives with 1 thread = ~1100MB/s
___
kura1 btrfs_test # sysctl vm.drop_caches=1 ; for j in {1..1} ; do dd
of=/dev/null if=/tmp/btrfs_test/testfile_bs1m_size10GB_${j} bs=1M &
done
10485760000 bytes (10 GB) copied, 9.69881 s, 1.1 GB/s
kura1 btrfs_test # sysctl vm.drop_caches=1 ; for j in {1..1} ; do dd
of=/dev/null if=/tmp/btrfs_test/testfile_bs1m_size10GB_${j} bs=1M &
done
10485760000 bytes (10 GB) copied, 9.56475 s, 1.1 GB/s
___
=================
btrfs raid6 on 6 drives with 2 thread = ~500MB/s
___
kura1 btrfs_test # sysctl vm.drop_caches=1 ; for j in {1..2} ; do dd
of=/dev/null if=/tmp/btrfs_test/testfile_bs1m_size10GB_${j} bs=1M &
done
10485760000 bytes (10 GB) copied, 41.3899 s, 253 MB/s
10485760000 bytes (10 GB) copied, 41.6916 s, 252 MB/s
kura1 btrfs_test # sysctl vm.drop_caches=1 ; for j in {1..2} ; do dd
of=/dev/null if=/tmp/btrfs_test/testfile_bs1m_size10GB_${j} bs=1M &
done
10485760000 bytes (10 GB) copied, 40.3178 s, 260 MB/s
10485760000 bytes (10 GB) copied, 41.4087 s, 253 MB/s
___
btrfs raid6 on 6 drives with 1 thread = ~600MB/s
___
kura1 btrfs_test # sysctl vm.drop_caches=1 ; for j in {1..1} ; do dd
of=/dev/null if=/tmp/btrfs_test/testfile_bs1m_size10GB_${j} bs=1M &
done
10485760000 bytes (10 GB) copied, 17.5686 s, 597 MB/s
kura1 btrfs_test # sysctl vm.drop_caches=1 ; for j in {1..1} ; do dd
of=/dev/null if=/tmp/btrfs_test/testfile_bs1m_size10GB_${j} bs=1M &
done
10485760000 bytes (10 GB) copied, 17.5396 s, 598 MB/s
___
=================
btrfs raid5 on 3 drives with 2 thread = ~300MB/s
___
kura1 btrfs_test # sysctl vm.drop_caches=1 ; for j in {1..2} ; do dd
of=/dev/null if=/tmp/btrfs_test/testfile_bs1m_size10GB_${j} bs=1M &
done
10485760000 bytes (10 GB) copied, 67.636 s, 155 MB/s
10485760000 bytes (10 GB) copied, 70.1783 s, 149 MB/s
kura1 btrfs_test # sysctl vm.drop_caches=1 ; for j in {1..2} ; do dd
of=/dev/null if=/tmp/btrfs_test/testfile_bs1m_size10GB_${j} bs=1M &
done
10485760000 bytes (10 GB) copied, 69.4945 s, 151 MB/s
10485760000 bytes (10 GB) copied, 70.8279 s, 148 MB/s
___
btrfs raid5 on 3 drives with 1 thread = ~319MB/s
___
kura1 btrfs_test # sysctl vm.drop_caches=1 ; for j in {1..1} ; do dd
of=/dev/null if=/tmp/btrfs_test/testfile_bs1m_size10GB_${j} bs=1M &
done
10485760000 bytes (10 GB) copied, 32.8559 s, 319 MB/s
kura1 btrfs_test # sysctl vm.drop_caches=1 ; for j in {1..1} ; do dd
of=/dev/null if=/tmp/btrfs_test/testfile_bs1m_size10GB_${j} bs=1M &
done
10485760000 bytes (10 GB) copied, 32.8483 s, 319 MB/s
___
=================
btrfs (no raid) on 1 drive with 2 thread = ~155MB/s
___
kura1 btrfs_test # sysctl vm.drop_caches=1 ; for j in {1..2} ; do dd
of=/dev/null if=/tmp/btrfs_test/testfile_bs1m_size10GB_${j} bs=1M &
done
10485760000 bytes (10 GB) copied, 134.982 s, 77.7 MB/s
10485760000 bytes (10 GB) copied, 135.237 s, 77.5 MB/s
kura1 btrfs_test # sysctl vm.drop_caches=1 ; for j in {1..2} ; do dd
of=/dev/null if=/tmp/btrfs_test/testfile_bs1m_size10GB_${j} bs=1M &
done
10485760000 bytes (10 GB) copied, 134.549 s, 77.9 MB/s
10485760000 bytes (10 GB) copied, 135.293 s, 77.5 MB/s
___
btrfs (no raid) on 1 drive with 1 thread = ~162MB/s
___
kura1 btrfs_test # sysctl vm.drop_caches=1 ; for j in {1..1} ; do dd
of=/dev/null if=/tmp/btrfs_test/testfile_bs1m_size10GB_${j} bs=1M &
done
10485760000 bytes (10 GB) copied, 64.5931 s, 162 MB/s
kura1 btrfs_test # sysctl vm.drop_caches=1 ; for j in {1..1} ; do dd
of=/dev/null if=/tmp/btrfs_test/testfile_bs1m_size10GB_${j} bs=1M &
done
10485760000 bytes (10 GB) copied, 64.6299 s, 162 MB/s
___
=================
On Fri, Apr 26, 2013 at 4:21 PM, Matt Pursley <mpursley@gmail.com>
wrote:> Hey Josef,
>
> Thanks for looking into this further! That is about the same
> results that I was seeing, though I didn''t test it with just one
> drive.. only with all 12 drives in my jbod. I will do a test with
> just one disk, and see if I also get the same results.
>
> Let me know if you also see the same results with multiple drives in
> your raid...
>
>
> Thanks,
> Matt
>
>
>
>
>
> On Thu, Apr 25, 2013 at 2:10 PM, Josef Bacik <jbacik@fusionio.com>
wrote:
>> On Thu, Apr 25, 2013 at 03:01:18PM -0600, Matt Pursley wrote:
>>> Ok, awesome, let me know how it goes.. I don''t have the
raid
>>> formatted to btrfs right now, but I could probably do that in about
30
>>> minutes or so.
>>>
>>
>> Huh so I''m getting the full bandwidth, 120 mb/s with one
thread and 60 mb/s with
>> two threads. These are just cheap sata drives tho, I''ll try
and dig up a box
>> with 3 fusion cards for something a little closer to the speeds you are
seeing
>> and see if that makes a difference. Thanks,
>>
>> Josef
--
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