[lustre-discuss] Lustre on ZFS pooer direct I/O performance
Riccardo.Veraldi at cnaf.infn.it
Fri Oct 14 12:22:32 PDT 2016
I would like how may I improve the situation of my lustre cluster.
I have 1 MDS and 1 OSS with 20 OST defined.
Each OST is a 8x Disks RAIDZ2.
A single process write performance is around 800MB/sec
anyway if I force direct I/O, for example using oflag=direct in dd, the
write performance drop as low as 8MB/sec
with 1MB block size. And each write it's about 120ms latency.
I used these ZFS settings
options zfs zfs_prefetch_disable=1
options zfs zfs_txg_history=120
options zfs metaslab_debug_unload=1
i am quite worried for the low performance.
Any hints or suggestions that may help me to improve the situation ?
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