去年买的一块Seagate Backup Plus 4TB, 专门用来备份的, 之前在win7下用过几次, 但是在Ubuntu下可能只用过一两次, 今天备份的时候, 感觉写入速度不太正常, 大概只有12~15MB/s的样子, 硬盘原来出厂设置的分区是单独一个NTFS分区, 我怀疑是NTFS分区在Linux下速度有影响, 于是重新分区格式化为ext4. 但是发现速度更慢了, 读写都只有1.5MB/s, 慢到极点.
硬盘信息
$ sudo smartctl -x /dev/sdc1 smartctl 6.6 2016-05-31 r4324 [x86_64-linux-4.15.0-36-generic] (local build) Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org === START OF INFORMATION SECTION === Vendor: Seagate Product: BUP BL Revision: 0304 Compliance: SPC-4 User Capacity: 4,000,787,029,504 bytes [4.00 TB] Logical block size: 512 bytes Physical block size: 4096 bytes Logical Unit id: 0x5000000000000001 Serial number: NA9F8ZJ6 Device type: disk Local Time is: Thu Oct 4 20:01:57 2018 CST SMART support is: Available - device has SMART capability. SMART support is: Disabled Temperature Warning: Disabled or Not Supported Read Cache is: Enabled Writeback Cache is: Enabled === START OF READ SMART DATA SECTION === SMART Health Status: OK Current Drive Temperature: 0 C Drive Trip Temperature: 0 C Error Counter logging not supported Device does not support Self Test logging Device does not support Background scan results logging
在google中搜Seagate Backup Plus Ubuntu slow能查到不少相似的问题记录, 主要原因一是说Linux对SMR硬盘的支持, 另一是说主板BIOS, 其中有一个提供的解决办法是用gparted做成GPT分区, 按这个方法处理后, 硬盘速度就恢复正常了. 现在读写的benchmark是 66MB/s 和 20MB/s, 在大文件写入中显示的写入速度在25~40MB/s之间. 因为SMR硬盘本身性能的影响, 在连续写入大概90GB后, 写入速度会快速下降
installed 'gparted' and then created GPT partition table via "Device-> Create partition table-> GPT". Then i created desired number of partitions with formats such as ntfs, ext4 etc... Now it works fine!
SMR中文叫叠瓦式磁记录, 关于SMR硬盘的说明, 可以参考知乎的这两篇 https://www.zhihu.com/question/31941970 和 https://www.zhihu.com/question/278755486 . SMR硬盘的写入性能非常差, 正常就只有20~30MB/s, 不适合用于大量写的场景(例如系统盘, 以及阵列), 目前7mm的2.5硬盘基本都是SMR的, 9mm的2T只有这一款 ST2000LM003