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CESNET - ~400TB disk array for HSM system using both FC and SATA disks (2011)
Brief disk array requirements:
- Two types of disk in one disk array, no automatic tiering within the array required (there was an HSM system for doing this on a file level)
- Tier 1 - FC, SAS or SCSI drives, min. 15k RPM, totally min. 50TB consisting of 120x 600GB drives + 3 hot spares
- Tier 2 - SATA drives, min. 7.2.k RPM, totally min. 300TB, min. 375x1TB + 10 hot spares OR 188x2TB + 5 hot spares
Performance requirements:
- Sequential: there will be 10TB cluster filesystem on the disk array using RAID5 or R6, this file system will be part of the HSM system. This filesystem will connected to one of front end servers (technical solutions of the connection is up to the candidates, e.g. MPIO, # FC channels, etc., but the solution must be identical to what is used in the proposal). The following benchmark will be run using iozone v3.347:
iozone -Mce -t200 -s15g -r512k -i0 -i1 -F path_to_files
The result of the test is an average value of three runs of the abovementioned command as „Children see throughput for 200 initial writers”, respektiveand , „Children see throughput for 200 readers”.
Minimum read speed 1600MB/s, minimum write sped speed 1200MB/s.
Random:
Same setup of the volume as in the sequential test, but for this test, it will be connected without any filesystem (on a block level). The following test will be run on the connected LUN using fio v1.4.1 with this test definition:
No Format [global] description=CESNET_test [cesnet] # change it to name of the block device used filename=XXXX rw=randrw # 70% rand read, 30% rand write rwmixread=70 size=10000g ioengine=libaio bs=2k runtime=8h time_based numjobs=32 group_reporting # --- end ---
The result of the test is sum of write and read IO operations divided by total elapsed time of the test in seconds.
Minimum required performance 9000 IOPs.
Results of the tests required as a part of : YES
Notes after evaluation: the tests themselves were OK, but the test architectures could be defined a bit better: The tests actually measured only performance of the FC disks (candidates obviously configured the volume in such a way that it was faster), performance of SATA volumes was not evaluated at all. Also, the winner used RAID5 as required but there was a big RAID0 volume above the 20 individual RAID5s (thus creating RAID50) which was allowed but not used in production afterwards.
File system benchmarking examples:
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