Oracle 1.6TB NVMe SSD, Руководство пользователя

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Drive Volume Management
26 Oracle 1.6TB NVMe SSD User Guide • July 2015
■
Block size can be configured through a server operating system or file system and is set to a
default size with Oracle databases.
■
The Oracle 1.6TB NVMe SSDs is designed to provide best performance for data transfers
that are multiples of 4k size and using addresses that are 4k aligned. Partitions should be
aligned to start on 4k boundaries.
■
The ZFS file system might require manual alignment. The Oracle 1.6TB NVMe SSD has a
maximum transfer size of 128k. IO requests for larger transfer sizes are broken into transfer
sizes of size 128k or smaller. For optimal performance, transfer sizes should be limited to
128k to avoid additional overhead associated with breaking into smaller transfer sizes.
■ The Oracle 1.6TB NVMe SSD should be formatted using a label of type
EFI
(
format -e
command).
Ensure that when the EFI label is created by ZFS, the default start sector is 256, which
aligns S1 with 128k (if the block size is 512). The
vtoc
label default cylinder size is 50176
(224*224) blocks. If the block size is 512, the default Oracle Solaris Operating System
partition aligns with 512k. For example: 50176*512 = 49*512*1024 .
Specify and ensure 4k alignment: The default start sector of 34 for
EFI
labels is not a 4k
aligned value. Use the partition subcommand of the Solaris
format
command to change the
start sector to 256, or any other 128k aligned value. Note that there are 512B per sector.
■
The ZFS file system automatically aligns partitions to start on 8k boundaries when a full
disk is allocated to ZFS (recommended). If you allocate individual
EFI
partitions to a ZFS
pool, ensure the partition is 4k-aligned as discussed above. For optimal performance of ZFS
with the 1.6TB NVMe SSD, refer to the ZFS Best Practices Guide and the ZFS Evil Tuning
Guide .
■
For highest performance, make sure that the system meets the physical, environmental, and
electrical specifications listed in “Specifications” on page 15 .
Related Information
■
“Preparing the NVMe Storage Drive for Installation”
■
https://wikis.oracle.com/display/systemsperformance/Flash+and+SSD
+Performance
■ Tuning ZFS When Using Flash Storage
http://docs.oracle.com/cd/E26502_01/html/
E29022/chapterzfs-flash.html
Drive Volume Management
A volume manager can present multiple SSD devices as one larger volume. Use the Automatic
Storage Management (ASM) volume manager or other volume manager to concatenate multiple
flash memory domains. For example, a volume manager can be used to concatenate four 1.6 TB
domains into a single 6.4 TB volume.