fsync tests
am 07.06.2010 01:07:42 von RBN--001636c5c28591c3a90488649ff9
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I ran test_fsync on a local ext 3 partition and on a raid jfs SSD array
8x32GB RAID10. The local disk returned quickly and gave what looks like
acceptable results. However, the RAID looks pretty bad. Any one have any
idea why fsync would take so long on an SSD RAID 10.
LOCAL DISK
Simple write timing:
write 0.005460
Compare fsync times on write() and non-write() descriptor:
(If the times are similar, fsync() can sync data written
on a different descriptor.)
write, fsync, close 0.072429
write, close, fsync 0.075627
Compare one o_sync write to two:
(o_sync unavailable)
(o_dsync unavailable)
write, fdatasync 0.075907
write, fsync, 0.076320
Compare file sync methods with 2 8k writes:
(o_dsync unavailable)
write, fdatasync 0.108367
write, fsync, 0.108659
RAID 10 SSD jfs
Simple write timing:
write 0.004843
Compare fsync times on write() and non-write() descriptor:
(If the times are similar, fsync() can sync data written
on a different descriptor.)
write, fsync, close 95.546382
write, close, fsync 51.407276
Compare one o_sync write to two:
(o_sync unavailable)
(o_dsync unavailable)
write, fdatasync 10.999764
write, fsync, 80.696959
Compare file sync methods with 2 8k writes:
(o_dsync unavailable)
write, fdatasync 111.931881
write, fsync, 99.329298
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I ran test_fsync on a local ext 3 partition and on a raid jfs SSD a=
rray 8x32GB RAID10.=A0 The local disk returned quickly and gave what looks =
like acceptable results.=A0 However, the RAID looks pretty bad.=A0 Any one =
have any idea why fsync would take so long on an SSD RAID 10.
LOCAL DISK
Simple write timing:
=A0 write =
=A0 0.005460
Compare fsync=
times on write() and non-write() descriptor:
(If the times are similar,=
fsync() can sync data written
=A0on a different descriptor.)
=A0 write, fsync, close =A0 0.072429
=A0 write, c=
lose, fsync =A0 0.075627
Compare one o_sync write to two:=
=A0 (o_sync unavailable)=A0
=A0 (o_dsync unavailable)=
=A0
=A0 write, fdatasync 0.075907
=A0 write, fsync, =A0 0.076320
Co=
mpare file sync methods with 2 8k writes:
=A0 (o_dsync unavailable=
)=A0
=A0 write, fdatasync 0.108367
=A0=
write, fsync, =A0 0.108659
<=
br>RAID 10 SSD jfs
Simple write timing:
=A0 write =
=A0 0.004843
Compare fsync times on write() and no=
n-write() descriptor:
(If the times are similar, fsync() can sync data w=
ritten
=A0on a different descriptor.)
=A0 write, fsync, close 95.546382
=A0 write, clo=
se, fsync 51.407276
Compare one o_sync write to two:
=
=A0 (o_sync unavailable)=A0
=A0 (o_dsync unavailable)=A0
=A0 write, fsync, 80.696959
Comp=
are file sync methods with 2 8k writes:
=A0 (o_dsync unavailable)=
=A0
=A0 write, fdatasync 111.931881
=
=A0 write, fsync, 99.329298
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