Isilon：NetWorker NSM for NAS - Isilon 或 PowerScale 快照可浏览恢复失败，并在 Linux NetWorker 服务器上显示 Permission Denied 错误。

Summary: 在基于 Linux 的 NetWorker 服务器上进行 NAS 可浏览恢复的 NSM 期间，要恢复的快照被 NFS 临时装载在“/nsr/tmp”下，以允许浏览以进行粒度恢复。有时，快照的装载可能会失败，并显示“Permission Denied”（权限被拒绝）错误消息。

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Symptoms

装载操作失败后，将显示一条错误消息。如果使用 NMC 进行恢复，它类似于主机'networkerserver.dell.com'上的“Unable to open directory '/nsr/tmp/1234.1234567' ”。Permission denied“（权限被拒绝）。如果使用命令行“nsrsnapadmin”执行恢复，则类似于“装载时服务器拒绝访问”。

Cause

NetWorker 服务器上的“root”用户需要足够的权限才能遍历已装载的快照。NetWorker 服务器上的“root”用户需要目录上的“读取”和“执行”权限，才能遍历已装载的快照并查看其中的内容。

在此特定情况下，Isilon/PowerScale“/ifs/data”最初具有这些权限，可以正常工作。 
powerscale.dell.com# ls -led /ifs/data
drwxr-xr-x     6 root  wheel  113 Mar 28 13:10 /ifs/data
OWNER: user:root
GROUP: group:wheel
SYNTHETIC ACL
0: user:root allow dir_gen_read,dir_gen_write,dir_gen_execute,std_write_dac,delete_child
1: group:wheel allow dir_gen_read,dir_gen_execute
2: everyone allow dir_gen_read,dir_gen_execute
随后，此文件系统对其权限进行了更改，从而触发了此行为 — 请注意，“everyone”的“read”和“execute”权限会在文件系统上删除 
powerscale.dell.com# chmod 700 /ifs/data
powerscale.dell.com# ls -led /ifs/data
drwx------     6 root  wheel  113 Mar 28 13:10 /ifs/data
OWNER: user:root
GROUP: group:wheel
SYNTHETIC ACL
0: user:root allow dir_gen_read,dir_gen_write,dir_gen_execute,std_write_dac,delete_child
1: group:wheel allow std_read_dac,std_synchronize,dir_read_attr
从逻辑上讲，NetWorker 正在对快照进行 NFS 装载，并将路径放置在“/nsr/tmp/123.1234567”下 — 这可以手动完成（在 NetWorker 之外），在尝试遍历已装载的文件系统时，也会观察到同样的问题。此“Permission Denied”错误是 NFS 本身的一个特征。下面是装载相同快照并尝试遍历它（不带 NetWorker）的示例。

在 NFS 配置上装载和浏览时具有正确的权限（NetWorker 服务器上的“root”用户在 /ifs/data 目录上具有读/执行访问权限）。 
[root@networkerserver.dell.com tmp]# mount powerscale.dell.com:/ifs/data/.snapshot/NSMNAS-20220329075723-1648537042-0 /tmp/mount
[root@networkerserver.dell.com tmp]# ls -l /tmp/mount
total 8
drwxr-xr-x 5 root root  77 Jul  4  2021 Isilon_Support
drwxr-xr-x 2 root root  30 Dec 22  2020 recoverfolder
drwxr-xr-x 2 root root 176 Mar 23 14:27 testbackup
 
在 NFS 配置上装载和浏览时具有不正确的权限（NetWorker 服务器上的 root 用户在 /ifs/data 目录上被拒绝读/执行访问权限）。 
[root@networkerserver.dell.com tmp]# mount powerscale.dell.com:/ifs/data/.snapshot/NSMNAS-20220329075723-1648537042-0 /tmp/mount
[root@networkerserver.dell.com tmp]# ls -l /tmp/mount
ls: cannot open directory /tmp/mount: Permission denied

Resolution

1.在创建快照时，对文件系统上的“everyone”拥有“read”和“execute”权限。

2.通过在 Isilon/PowerScale 上创建 NFS 共享，为 NetWorker 服务器的“root”用户分配必要的权限。

尝试装载快照以使用命令行浏览快照时（“/ifs/data”在拍摄快照时具有 700 个权限，并且未创建 NFS 导出）。 
[root@networkerserver.dell.com ~]# nsrsnapadmin -s networkerserver.dell.com -M networkerserver.dell.com -c powerscale.dell.com -S 3863397257 -r
180437:nsrsnapadmin:Trying NAS credentials from 'NSR client' 'powerscale.dell.com', group 'SNAP/NASSNAPWF/BACKUP/NAS'
38008:(pid 12645):Snapshot not found
173276:nsrsnapadmin: Will retry to mount path '/net/powerscale.dell.com/ifs/data/.snapshot/NSMNAS-20220401101904-1648804743-0' 4 more times: Unable to mount '/net/powerscale.dell.com/ifs/data/.snapshot/NSMNAS-20220401101904-1648804743-0': Command 'mount -t nfs "powerscale.dell.com:/ifs/data/.snapshot/NSMNAS-20220401101904-1648804743-0" "/nsr/tmp/12645.1648806854" 2>&1' exited with code 32: mount.nfs: access denied by server while mounting powerscale.dell.com:/ifs/data/.snapshot/NSMNAS-20220401101904-1648804743-0
173276:nsrsnapadmin: Will retry to mount path '/net/powerscale.dell.com/ifs/data/.snapshot/NSMNAS-20220401101904-1648804743-0' 3 more times: Unable to mount '/net/powerscale.dell.com/ifs/data/.snapshot/NSMNAS-20220401101904-1648804743-0': Command 'mount -t nfs "powerscale.dell.com:/ifs/data/.snapshot/NSMNAS-20220401101904-1648804743-0" "/nsr/tmp/12645.1648806859" 2>&1' exited with code 32: mount.nfs: access denied by server while mounting powerscale.dell.com:/ifs/data/.snapshot/NSMNAS-20220401101904-1648804743-0
173276:nsrsnapadmin: Will retry to mount path '/net/powerscale.dell.com/ifs/data/.snapshot/NSMNAS-20220401101904-1648804743-0' 2 more times: Unable to mount '/net/powerscale.dell.com/ifs/data/.snapshot/NSMNAS-20220401101904-1648804743-0': Command 'mount -t nfs "powerscale.dell.com:/ifs/data/.snapshot/NSMNAS-20220401101904-1648804743-0" "/nsr/tmp/12645.1648806865" 2>&1' exited with code 32: mount.nfs: access denied by server while mounting powerscale.dell.com:/ifs/data/.snapshot/NSMNAS-20220401101904-1648804743-0
尝试装载快照以使用命令行浏览快照时， “/ifs/data” 在拍摄快照时具有 700 个权限，并且在 Isilon 上正确创建了 NFS 导出，以允许 NetWorker 服务器上的“root”用户通过 NFS 遍历快照。 
[root@networkerserver.dell.com ~]# nsrsnapadmin -s networkerserver.dell.com -M networkerserver.dell.com -c powerscale.dell.com -S 3863397257 -r
180437:nsrsnapadmin:Trying NAS credentials from 'NSR client' 'powerscale.dell.com', group 'SNAP/NASSNAPWF/BACKUP/NAS'
38008:(pid 10873):Snapshot not found
Current working directory is /ifs/data/
snaprecover> ls -l
total 8
drwxr-xr-x root               77 Jul 04 2021 Isilon_Support
drwxr-xr-x root               30 Dec 22 2020 recoverfolder
drwxr-xr-x root              176 Mar 23 14:27 testbackup

Affected Products

NetWorker Family, Isilon, NetWorker
Article Properties
Article Number: 000198204
Article Type: Solution
Last Modified: 01 Jun 2023
Version:  4
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