记一次rsync在nfs环境下错误处理

公司有一应用，即利用rsync开源工具从生产机拉归档日志至备份机，rsync命令从备份机发起，实现类似ftp下载的功能，但是近期发现rsync获取归档日志的时候，发现以下错误：
[quote]$ sudo rsync -av --port=2008 hisdb02::mcdbra/archlog/orcl1/1_44792_698764072.dbf /tmp

receiving incremental file list
rsync: send_files failed to open "/archlog/orcl1/1_44792_698764072.dbf" (in mcdbra): Permission denied (13)[/quote]
日志显示生产机无法open归档日志1_44792_698764072.dbf，进一步检查得知该归档日志存放在nfs文件系统上。
[quote]root@hisdb02:/var/adm#df
Filesystem 512-blocks Free %Used Iused %Iused Mounted on
/dev/hd4 2097152 1995896 5% 2323 2% /
/dev/hd2 6815744 3685120 46% 37222 9% /usr
/dev/hd9var 2097152 178200 92% 443 3% /var
/dev/hd3 33554432 29460648 13% 1390 1% /tmp
/dev/hd1 2097152 1626432 23% 488 1% /home
/proc - - - - - /proc
/dev/hd10opt 2097152 1917288 9% 2745 2% /opt
/dev/lvoracle 62914560 27519376 57% 76569 3% /oracle
/dev/fslv00 2086666240 748941176 65% 382 1% /rman
/dev/lvdbra 83886080 78608608 7% 25150 1% /dbra
/dev/lvarch 104857600 76068312 28% 370 1% /archlog/orcl2
hisdb01:/archlog/orcl1 167772160 130979864 22% 4995 1% /archlog/orcl1[/quote]
但是在hisdb02主机上对目录/archlog/orcl1有读写权限，但没有赋权或者更改文件属主的权限。
[quote]root@hisdb02:/archlog/orcl1#chown oracle:dba lll
chown: lll: Operation not permitted.[/quote]
在hisdb02上检查/etc/filesystems配置文件，似乎也没有明显错误：
[quote]/archlog/orcl1:
dev= "/archlog/orcl1"
vfs= nfs
nodename= hisdb01
mount= true
type= nfs
options= rw,bg,hard,intr,vers=3,rsize=32768,wsize=32768,timeo=600,proto=tcp,biods=32
account= false[/quote]
直觉告诉我，rsync出现这个错误，应该和nfs特定的权限有关，于是进一步在hisdb01上检查nfs配置文件/etc/exports,可以看到配置文件中并没有显示赋予root访问权限。
[quote]root@hisdb01:/#cat /etc/exports
/archlog/orcl1 -rw,access=hisdb02[/quote]
于是添加root显示访问权限
[quote]root@hisdb01:/#cat /etc/exports
/archlog/orcl1 -rw,root=hisdb02,access=hisdb02[/quote]
AIX对于选项的解释如下：
[quote]rw = Client [:Client]
Exports the directory with read-write permission to the specified Clients. Exports the directory read-only to Clients not in the list. A read-write list cannot be specified if a read-only list has been specified.

access = Client[:Client,...]
Gives mount access to each Client listed. If not specified, any Client is allowed to mount the specified directory

root=Client[:Client]
[color=red]Allows root access from the specified Clients. Clients not in the list are not allowed root access[/color].[/quote]
为保险起见在hisdb01重新exportfs -a，然后在hisdb02重新umount，mount nfs文件系统之后，问题解决。
附：
在aix上修改配置文件/etc/exports除了手工编辑之外，aix还提供smitty 接口用于修改
[quote]root@hisdb01:/#smit chnfsexp


* Pathname of directory to export /archlog/orcl1
Anonymous UID [-2]
Public filesystem? [no] +
* Change export now, system restart or both both +
Pathname of alternate exports file []
Allow access by NFS versions []
External name of directory (NFS V4 access only) []
Referral locations (NFS V4 access only) []
Replica locations []
Ensure primary hostname in replica list yes +
Allow delegations? []
Security method 1 [sys,none] +
Mode to export directory [read-write] +
Hostname list. If exported read-mostly []
Hosts & netgroups allowed client access [hisdb02]
Hosts allowed root access [hisdb02]
Security method 2 [] +
Mode to export directory [] +
Hostname list. If exported read-mostly []
Hosts & netgroups allowed client access []
Hosts allowed root access []
Security method 3 [] +
Mode to export directory [] +
Hostname list. If exported read-mostly []
Hosts & netgroups allowed client access []
Hosts allowed root access []
Security method 4 [] +
Mode to export directory [] +
Hostname list. If exported read-mostly []
Hosts & netgroups allowed client access []
Hosts allowed root access [][/quote]

或者通过chnfsexp命令进行修改
[quote]/usr/sbin/chnfsexp -d '/archlog/orcl1' '-B' -S 'sys,none' -t 'rw' -c 'hisdb02' -r 'hisdb02'[/quote]