[OpenIndiana-discuss] ashift 13?
jason matthews
jason at broken.net
Thu Apr 9 00:12:56 UTC 2015
cross posting to zfs
The data seems to indicate that something strange is happening between
the compression algorithms and sector sizes > 512 bytes. ZFS reports
virtually the same compression ratios for either ashift=9 or ashift=12
zpools, but the number of data blocks consumed varies drastically
between 9 bit and 12 bit sectors. Uncompressed file systems report the
same disk usage so the problem seems tied towards the compression
mechanisms. Moving to 13 bit, as the illumos advanced sector wiki page
implies, results in even more amplication.
why should 4k sectors consume nearly 2x storage compressed versus 512
byte zpools? this looks like some sort of bug to me.
With Identical datasets installed on each file system we see a almost 2x
magnification in disk usage in ashift=12 versus ashift=9.
Do you any of you big brains on the ZFS team know why this happens?
Is this a bug? Some sort of errant behavior in the Intel DC S3700?
If it is not a bug, why would we want to move to 4k sectors?
Is this a case where ZFS compression isnt tuned against 4k blocks?
should I file a ticket?
root at dbb005:/root# zfs list -r ashift9 ashift12 |grep postgres
ashift12/128k/lz4/postgres 355G 40.7G 355G
/ashift12/128k/lz4/postgres
ashift12/128k/lzjb/postgres 403G 40.7G 403G
/ashift12/128k/lzjb/postgres
ashift12/128k/no-compression/postgres 640G 40.7G 640G
/ashift12/128k/no-compression/postgres
ashift12/8k/lz4/postgres 355G 40.7G 355G
/ashift12/8k/lz4/postgres
ashift12/8k/lzjb/postgres 403G 40.7G 403G
/ashift12/8k/lzjb/postgres
ashift9/128k/lz4/postgres 224G 6.32T 224G
/ashift9/128k/lz4/postgres
ashift9/128k/lzjb/postgres 277G 6.32T 277G
/ashift9/128k/lzjb/postgres
ashift9/128k/no-compression/postgres 638G 6.32T 638G
/ashift9/128k/no-compression/postgres
ashift9/8k/lz4/postgres 224G 6.32T 224G
/ashift9/8k/lz4/postgres
ashift9/8k/lzjb/postgres 224G 6.32T 224G
/ashift9/8k/lzjb/postgres
root at dbb005:/root# zfs get -r compressratio ashift9 ashift12 | grep
postgres |grep -v @
ashift12/128k/lz4/postgres compressratio 2.86x -
ashift12/128k/lzjb/postgres compressratio 2.31x -
ashift12/128k/no-compression/postgres compressratio 1.00x -
ashift12/8k/lz4/postgres compressratio 2.86x -
ashift12/8k/lzjb/postgres compressratio 2.31x -
ashift9/128k/lz4/postgres compressratio 2.86x -
ashift9/128k/lzjb/postgres compressratio 2.31x -
ashift9/128k/no-compression/postgres compressratio 1.00x -
ashift9/8k/lz4/postgres compressratio 2.86x -
ashift9/8k/lzjb/postgres compressratio 2.86x -
root at dbb005:/root# zpool status ashift12 ashift9
pool: ashift12
state: ONLINE
scan: none requested
config:
NAME STATE READ WRITE CKSUM
ashift12 ONLINE 0 0 0
c3t55CD2E404B63FCD9d0 ONLINE 0 0 0
c3t55CD2E404B64033Bd0 ONLINE 0 0 0
c3t55CD2E404B63F93Cd0 ONLINE 0 0 0
errors: No known data errors
root at dbb005:/root# zdb ashift12 |egrep ashift:
ashift: 12
ashift: 12
ashift: 12
ashift: 12
ashift: 12
ashift: 12
pool: ashift9
state: ONLINE
scan: none requested
config:
NAME STATE READ WRITE CKSUM
ashift9 ONLINE 0 0 0
c3t55CD2E404B417CFEd0 ONLINE 0 0 0
c3t55CD2E404B43F0C9d0 ONLINE 0 0 0
c3t55CD2E404B640592d0 ONLINE 0 0 0
c3t55CD2E404B43F183d0 ONLINE 0 0 0
c3t55CD2E404B417D1Fd0 ONLINE 0 0 0
c3t55CD2E404B43F14Cd0 ONLINE 0 0 0
c3t55CD2E404B43EFAAd0 ONLINE 0 0 0
c3t55CD2E404B43EFCCd0 ONLINE 0 0 0
c3t55CD2E404B41904Ad0 ONLINE 0 0 0
c3t50015178F3659395d0 ONLINE 0 0 0
c3t55CD2E404B64062Fd0 ONLINE 0 0 0
errors: No known data errors
root at dbb005:/root# zdb ashift9 |egrep ashift:
ashift: 9
ashift: 9
ashift: 9
ashift: 9
ashift: 9
ashift: 9
ashift: 9
ashift: 9
ashift: 9
ashift: 9
ashift: 9
ashift: 9
ashift: 9
ashift: 9
ashift: 9
ashift: 9
ashift: 9
ashift: 9
ashift: 9
ashift: 9
ashift: 9
ashift: 9
root at dbb005:/root# iostat -En
c3t55CD2E404B417CFEd0 Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: ATA Product: INTEL SSDSC2BA80 Revision: DL04 Serial No:
BTTV331202X3800
Size: 800.17GB <800166076416 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 0 Predictive Failure Analysis: 0
c3t55CD2E404B41904Ad0 Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: ATA Product: INTEL SSDSC2BA80 Revision: DL04 Serial No:
BTTV331207RE800
Size: 800.17GB <800166076416 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 0 Predictive Failure Analysis: 0
c3t55CD2E404B8149FAd0 Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: ATA Product: INTEL SSDSC2CT18 Revision: 335u Serial No:
CVKI338200ZT180
Size: 180.05GB <180045766656 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 0 Predictive Failure Analysis: 0
c3t55CD2E404B43EFAAd0 Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: ATA Product: INTEL SSDSC2BA80 Revision: DL04 Serial No:
BTTV333005CU800
Size: 800.17GB <800166076416 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 0 Predictive Failure Analysis: 0
c3t55CD2E404B406BBCd0 Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: ATA Product: INTEL SSDSC2BA80 Revision: DL04 Serial No:
BTTV330209W2800
Size: 800.17GB <800166076416 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 0 Predictive Failure Analysis: 0
c3t55CD2E404B417D1Fd0 Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: ATA Product: INTEL SSDSC2BA80 Revision: DL04 Serial No:
BTTV331202Y3800
Size: 800.17GB <800166076416 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 0 Predictive Failure Analysis: 0
c3t55CD2E404B43F0C9d0 Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: ATA Product: INTEL SSDSC2BA80 Revision: DL04 Serial No:
BTTV333005ME800
Size: 800.17GB <800166076416 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 0 Predictive Failure Analysis: 0
c3t55CD2E404B43EFCCd0 Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: ATA Product: INTEL SSDSC2BA80 Revision: DL04 Serial No:
BTTV333005DU800
Size: 800.17GB <800166076416 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 0 Predictive Failure Analysis: 0
c3t50015178F3659395d0 Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: ATA Product: INTEL SSDSC2BA80 Revision: DL04 Serial No:
BTTV326303UP800
Size: 800.17GB <800166076416 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 0 Predictive Failure Analysis: 0
c3t55CD2E404B43F14Cd0 Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: ATA Product: INTEL SSDSC2BA80 Revision: DL04 Serial No:
BTTV333005RC800
Size: 800.17GB <800166076416 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 0 Predictive Failure Analysis: 0
c3t55CD2E404B43F183d0 Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: ATA Product: INTEL SSDSC2BA80 Revision: DL04 Serial No:
BTTV333005T3800
Size: 800.17GB <800166076416 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 0 Predictive Failure Analysis: 0
c3t55CD2E404B63FCD9d0 Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: ATA Product: INTEL SSDSC2BA80 Revision: 0270 Serial No:
BTTV420600LD800
Size: 800.17GB <800166076416 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 0 Predictive Failure Analysis: 0
c3t55CD2E404B640592d0 Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: ATA Product: INTEL SSDSC2BA80 Revision: 0270 Serial No:
BTTV420602JK800
Size: 800.17GB <800166076416 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 0 Predictive Failure Analysis: 0
c3t55CD2E404B63F93Cd0 Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: ATA Product: INTEL SSDSC2BA80 Revision: 0270 Serial No:
BTTV420505XQ800
Size: 800.17GB <800166076416 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 0 Predictive Failure Analysis: 0
c3t55CD2E404B64062Fd0 Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: ATA Product: INTEL SSDSC2BA80 Revision: 0270 Serial No:
BTTV420602P6800
Size: 800.17GB <800166076416 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 0 Predictive Failure Analysis: 0
c3t55CD2E404B64033Bd0 Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: ATA Product: INTEL SSDSC2BA80 Revision: 0270 Serial No:
BTTV4206020X800
Size: 800.17GB <800166076416 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 0 Predictive Failure Analysis: 0
All Intel DC S3700 drives used in the ashift9 and ashift12 zpools
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