[操作疑難] NAS 寫入速度慢

最近UPGRADE DESKTOP同NAS去10GbE, 之前用1Gbps一直唔知NAS讀寫速度
不過轉做10GbE後發現寫入速度奇慢, 讀取速度都不穩定

以CrystalMark Sequence測試

讀取最高可以1100 MB/s
但經常只有300 - 600 MB/s左右
寫入就一直維持 150 MB/s 左右

想知道咩情況同原因會有此問題發生, Harddisk 問題?

-
Synology DS1817+
8 Disks SHR2
16GB RAM
無SSD CACHE
AMP CAT6

0

0

t19922006

進階會員

Rank: 3 Rank: 3 Rank: 3

2^#

發表於 2021-7-30 16:04 | 只看該作者

本帖最後由 t19922006 於 2021-7-30 16:11 編輯

回覆 1# icemaou666

速度正常
以RAID6/SHR2理論上讀速度係咁多隻加哩
Max 150*8=1200 MB/s sequential read
write 因為要經CPU產生Parity Check data, 所以寫入唔會快咗

Read speed of the N-disk RAID6 is (N-2) times faster than the speed of a single drive, similar to RAID levels 0 and 5. If one or two drives fail in RAID6, the read speed degrades significantly because a reconstruction of missing blocks requires an entire row to be read.

There is no significant write speed improvement in RAID6 layout. RAID6 parity updates require even more processing than that in RAID5.
Write speed of a RAID5 is limited by the parity updates. For each written block, its corresponding parity block has to be read, updated, and then written back. Thus, there is no significant write speed improvement on RAID5, if any at all.

http://www.raid-calculator.com/raid-types-reference.aspx

TOP

tingcrab