PowerScale：因 ICAP 伺服器過載所導致的 NFS 效能問題

本 KB 中所述的對 NFS 的性能影響適用於配置了 ICAP 伺服器的群集。首先，檢查ICAP防病毒伺服器設置：
 

# 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

確認在一般效能指令檔中等待「av」或「av_wait」的 nfs 執行緒。
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

在受影響的時間範圍內，在受影響節點的記錄訊息中確認。
 

1. ICAP 伺服器使 /var/log/messages 中的消息過載
    

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 記錄顯示 ICAP 伺服器超載的跡象
    

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.

確認使用isi_get掃描的路徑。例如，上述訊息記錄中的 LIN 1：0c2e：9531 應與 NFS 匯出路徑相符。 
 

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

客戶的 ICAP 伺服器在開啟和關閉時掃描檔案時超載。ICAP 指南建議至少使用 1：1 的比例。

PowerScale OneFS CLI 管理指南-ICAP 伺服器

如需立即緩解，請停用「開啟時掃描」，然後測試效能。
 

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

如果問題仍然存在，請停用「關閉時掃描」，然後測試效能。
 

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

對於永久解決方案，如果希望同時啟用這兩個設置，請增加ICAP伺服器的數量。

關閉時掃描是建議的 1：1 ICAP 伺服器與節點比例。

打開時掃描是建議的 2：1 ICAP 伺服器與節點比率。