PowerScale：由于 ICAP 服务器过载导致的 NFS 性能问题

本知识库文章中描述的对 NFS 的性能影响适用于配置了 ICAP 服务器的群集。首先，检查 ICAP 防病毒服务器设置：
 

# isi antivirus icap settings view
 
           Fail Open: Yes
        Glob Filters: -
Glob Filters Enabled: No
Glob Filters Include: No
       Path Prefixes: /ifs/nasprod2024/smb
              Repair: No
       Report Expiry: 1W
       Scan On Close: Yes       <<<-- Enabled
        Scan On Open: Yes     <<<-- Enabled
Scan Cloudpool Files: No
   Scan Size Maximum: 100.00M
             Service: Yes
          Quarantine: Yes
            Truncate: No

确认在常规性能脚本中等待“av”或“av_wait”的 nfs 线程。
https://confluence.cec.lab.emc.com/display/ISILON/General+Performance+Troubleshooting
 

>>> Wait Channel Values<<<
11 av_wait
20 kqread
20 av
4 sbwait
1 opwres
4 sigwait
107 ucond

在受影响节点上受影响时间段内的日志消息中进行确认。
 

1. /var/log/messages 中的 ICAP 服务器重载消息
    

2025-05-06T17:42:20.639078-07:00 <0.5> nasprod2024-4(id4) /boot/kernel.amd64/kernel: [bam_av.c:1176](pid 14848="nfs")(tid=100543) Scan 1:155d:543d::HEAD failed with timeout (probably due to ICAP server overload); doing opdata cleanup with state: dequeued
2025-05-06T17:42:20.639138-07:00 <0.5> nasprod2024-4(id4) /boot/kernel.amd64/kernel: [bam_av.c:1176](pid 14848="nfs")(tid=100524) Scan 1:0c2e:9531::HEAD failed with timeout (probably due to ICAP server overload); doing opdata cleanup with state: dequeued

2025-05-06T17:00:03.571382-07:00 <0.5> nasprod2024-1(id1) /boot/kernel.amd64/kernel: /lib/libthr.so.3:_pthread_create+0x906
2025-05-06T17:00:03.571392-07:00 <0.5> nasprod2024-1(id1) /boot/kernel.amd64/kernel: --------------------------------------------------
2025-05-06T17:00:03.571403-07:00 <0.6> nasprod2024-1(id1) /boot/kernel.amd64/kernel: pid 68624 (isi_avscan_d), jid 0, uid 0: exited on signal 11 from pid 0 (unknown) (core dumped)
2025-05-06T17:00:03.905443-07:00 <3.3> nasprod2024-1(id1) isi_avscan_d[63725]: [0x4d07b71b3000] Setting process flag P_NO_SEMLOCK for avscan
2025-05-06T17:00:03.905857-07:00 <3.4> nasprod2024-1(id1) isi_avscan_d[63725]: [0x4d07b71b3000] isi_avscan_d starting up
2025-05-06T17:00:03.949657-07:00 <3.4> nasprod2024-1(id1) isi_avscan_d[63725]: [0x4d07b71b3000] isi_avscan_d completed start up, ready...

3. Avscan 日志显示 ICAP 服务器过载的迹象
    

2025-05-06T17:38:58.867768-07:00 <3.6> nasprod2024-1(id1) isi_avscan_d[63725]: [0x4d07b7998200] Scan request timeout exceeded and dropped for 1:17c5:0b6e::HEAD, policy id: SCAN_ON_OPEN, report id: SCAN_ON_OPEN.
2025-05-06T17:38:58.868241-07:00 <3.6> nasprod2024-1(id1) isi_avscan_d[63725]: [0x4d07b71b4900] Scan request timeout exceeded and dropped for 1:17b7:6f7d::HEAD, policy id: SCAN_ON_OPEN, report id: SCAN_ON_OPEN.
2025-05-06T17:38:58.868439-07:00 <3.6> nasprod2024-1(id1) isi_avscan_d[63725]: [0x4d07b7997300] Scan request timeout exceeded and dropped for 1:0e78:89b3::HEAD, policy id: SCAN_ON_OPEN, report id: SCAN_ON_OPEN.

确认使用 isi_get 扫描的路径。例如，消息日志中的上述 LIN 1：0c2e：9531 应与 NFS 导出路径匹配。 
 

A valid path for LIN 1:0c2e:9531::HEAD is /ifs/nasprod2024/nfs/libarc-p1/mysql/#ib_16384_0.dblwr

客户的 ICAP 服务器在打开和关闭时会因扫描文件而过载。ICAP 指南建议至少为 1：1 的比率。

PowerScale OneFS CLI 管理指南 — ICAP 服务器

要立即缓解问题，请禁用“打开时扫描”，然后测试性能。
 

# isi antivirus icap settings modify --scan-on-open=false

如果问题仍然存在，请禁用“关闭时扫描”，然后测试性能。
 

# isi antivirus icap settings modify --scan-on-close=false

对于永久解决方案，如果希望同时启用这两个设置，则增加 ICAP 服务器的数量。

关闭时扫描是建议的 1：1 ICAP 服务器与节点比率。

开放时扫描是建议的 2：1 ICAP 服务器与节点比率。