Note: You cannot set up a synchronous or semi synchronous SnapMirror relationship between the two nodes of an active/active configuration.
Snapmirror Sync Mode 不能在active/active两节点模式下设置snapmirror sync mode
NetApp Snapmirror 设置参数：
http://hd.kvsconsulting.us/netappdoc/733docs/html/ontap/onlinebk/GUID-47724B21-7C7E-4AC9-A497-9505B42C27AF.html
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NetApp中开启ftp服务
1、options ftpd.enable on
2、cifs setup中需要设置administrator密码，ftp登录并不是使用root密码进行认证的。
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Disk media error failure thresholds
About media error thresholds
To prevent a storage system panic or data loss that might occur if too many media errors are encountered during single-disk failure reconstruction, Data ONTAP tracks media errors on each active storage system disk and sends a disk failure request to the RAID system if system-defined media error thresholds are crossed on that disk.
Disk media error thresholds that trigger an immediate disk failure request include
More than twenty-five media errors (that are not related to disk scrub activity) occurring on a disk within a ten-minute periodThree or more media errors occurring on the same sector of a disk
If the aggregate is not already running in degraded mode due to single-disk failure reconstruction when the disk failure request is received, Data ONTAP fails the disk in question, swaps in a hot spare disk, and begins RAID reconstruction to replace the failed disk.
In addition, if one hundred or more media errors occur on a disk in a one-week period, Data ONTAP pre-fails the disk and causes Rapid RAID Recovery to start. For more information, see Predictive disk failure and Rapid RAID Recovery.
Failing disks at the thresholds listed in this section greatly decreases the likelihood of a storage system panic or double-disk failure during a single-disk failure reconstruction.
系统认为是坏磁盘的阈值：
1、在一个十分钟的周期内，出现25个以上的磁盘介质错误，系统会标记该磁盘为disk failure。
2、在同一块磁盘同一个扇区上，出现三个及以上的磁盘介质错误，系统会标记该磁盘为disk failure。
3、在一周内，若有100个以上的磁盘介质错误，系统会将该磁盘标记为pre-fail，并且系统会触发Rapid RAID Recovery，以防止系统的损坏及在单磁盘损坏重建时引起双磁盘损坏。
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hw_assist
hardware-assisted takeover功能，仅仅在安装和配置了Remote LAN Modules(RLMs)的系统上才能使用。它提供了远程访问，排错，登录及告警的功能。RLM模块并不需要在双节点的每个控制器上安装，但是安装了RLM模块的控制器上，会缩短系统的接管时间。
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anon=uid|name
If a request comes from user ID of 0 (root user ID on the client), use uid as the effective user ID unless the client host is included in the root option. The default value of uid is 65534. To disable root access, set uid to 65535. To grant root access to all clients, set uid to 0. The user ID can also be specified by a name string corresponding to an entry in /etc/passwd. - See more at: http://www.wafl.co.uk/tag/exports/#sthash.3eKPx1lF.dpuf
为了授权所有客户端具有root访问权限，设置anon=0。user ID也可以被指定成在/etc/passwd中相应的用户名。
关于nosuid
Disables creation of setuid and setgid executable files and mknod commands on the file system path. Unless the file system is a root partition of a diskless NFS client, you should set the nosuidoption to prevent NFS client users from creating setuid executable files and device nodes that careless or cooperating NFS server users could use to gain root access. Pre-existing setuid andsetgid executable files will continue to function as intended.
禁止客户端更改uid和gid权限。
参考链接：http://www.wafl.co.uk/tag/exports/
http://www.storageonline.com.cn/storage/nas/data-ontap-8-2-7-mode-nfs-access-management/
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snap list
Displays a single line of information for each snapshot. Along with the snapshot's name, it shows when the snapshot was created and the size of the snapshot. If you include the vol_name argument, list displays snapshot information only for the specified volume. With no arguments, it displays snapshot information for all volumes in the system, or all aggregates in the case of snaplist-A. If you supply the -n option, the snapshot space consumption (%/used and %/total) will not be displayed. This option can be helpful if there is a single file snap restore in progress, as the space information may take a substantial time to compute during the restore.
The %/used column shows space consumed by snapshots as a percentage of disk space being used in the volume. The %/total column shows space consumed by snapshots as a percentage of total disk space (both space used and space available) in the volume. The first number is cumulative for all snapshots listed so far, and the second number in parenthesis is for the specified snapshot alone.
%used 列显示vol已经使用空间中，被snapshot使用的百分比。%total列显示vol总的空间中（包括使用和未使用的空间），被snapshot使用的百分比。
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cifs 共享权限设置
useradmin user add user1 -g administrators(只要是用户属于administrators组，无论vol和qtree的共享权限是什么，此账户对vol和qtree都具有读写权限）
options wafl.wcc_minutes_valid 指定wafl文件系统凭据缓存的时间，默认为20分钟
options wafl.default_security_style 指定wafl文件系统默认的安全风格
可以用cifs terminate 关闭cifs共享，此时才能启用cifs setup
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qtree中oplock参数概念：
NAS的技术含量则远深于SAN。换个眼光看，NAS环境也可视作集中存放、分布访问的文件系统。CIFS环境下，Oplocks (opportunistic locks)使得客户端在一些场景下能够执行客户端缓存从而达到提前读取、延后写入的性能优化效果（不仅降低了延迟，也降低了网络流量）。
有写缓存就有数据丢失风险，任何文件系统和存储都是这样。当写缓存中有脏数据时，如果网络突然中断或客户端崩溃，数据就会丢失。缓存自身是不负责数据丢失后的错误修复的——这部分由应用处理，在应用架构设计时需要考虑这一点（例如Oracle在log写入后才确认commit成功，则data block buffer丢失后可通过redo log修复）。
NetApp FAS(filer)中的CIFS oplock机制默认是打开的；如果网络很不稳定，或者应用不允许缓存数据丢失却又没有错误修复机制，则可能需要关闭oplock：
整个系统关闭：options cifs.oplocks.enable off
部分卷或目录关闭：qtree oplocks name disable
打开oplock机制的话，存在一个多久断开的问题。Windows客户端向FAS发送open-file请求，FAS响应之后再经过至少”options cifs.oplocks.opendelta”毫秒，FAS才向客户端发送oplock断开请求，避免客户端刚打开文件就收到要断开的请求。（如果没有这个cifs.oplocks.opendelta延迟，某些情况下会话可能陷入紊乱：客户端申请、FAS端让它断开、客户端再申请、FAS端再申请断开……）。由于Windows和FAS在不同版本中都可能存在处理方式的调整，允许动态设置cifs.oplocks.opendelta选项的能力显得很有必要。
类似以下错误可以考虑调整（加大）该时延：
Mon Jul 25 14:23:52 CST [fas3140a: cifs.oplock.break.timeout:warning]: CIFS: An oplock break request to station 192.168.11.11() for filer FAS3140A, share share1, file \subdir\file.txt has timed out.
http://liaohairun.blog.163.com/blog/static/25799008201152911418628/
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cifs access 命令，更改NAS共享的权限
http://www.wafl.co.uk/cifs_access/
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netapp磁盘控制器转移
假设磁盘在某一个aggr中，如aggr0
首先需要disk fail 0a.00.16 此时0a.00.16磁盘会被放入Broken disk 列表中，如果此时该控制器有spare盘，将会自动进入aggr中进行rebuilding。
被放入Broken disk中的磁盘，不能改变ownership属性，需先用disk unfail命令将其恢复成spare盘，然后在高级模式下(priv set advanced)，用disk remove_ownership 命令，将该磁盘从原控制器中移除。此时，可以先关闭options disk auto_assign off 选项。然后，在想要获得该磁盘的控制器上，键入disk assign all,即可获得该磁盘。
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df -V 显式指定volname
NetApp2246-A> df -V vol1
Filesystem kbytes used avail capacity Mounted on
/vol/vol1/ 692636 152 692484 0% /vol/vol1/
/vol/vol1/.snapshot 36452 60 36392 0% /vol/vol1/.snapshot
df -A 显式指定aggrname
NetApp2246-A> df -A aggr0
Aggregate kbytes used avail capacity
aggr0 1032154216 492768952 539385264 48%
aggr0/.snapshot 0 1624 0 ---%
参考链接：
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FlexCache volume概念：
A FlexCache volume is a sparsely-populated volume on a local storage system that is backed by a volume on a different, possibly remote, storage system. A sparsely-populated volume, sometimes called a sparse volume, provides access to data in the remote volume without requiring that all the data be in the sparse volume.
You use FlexCache volumes to speed up access to remote data, or to offload traffic from heavily accessed volumes. Because the cached data must be ejected when the data is changed, FlexCache volumes work best for data that does not change often.
When a client requests data from the FlexCache volume, the data is read from the origin system and cached on the FlexCache volume. Subsequent requests for that data are then served directly from the FlexCache volume. This improves performance when the same data is accessed repeatedly, because after the first request, the data no longer has to travel across the network, or be served from an overloaded system.
是一个稀疏卷，可以用来缓存远程存储卷上的数据，或者缓存较高负荷系统上的数据，供本地调用。
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SP lan概念：
可以用来做串口重定向，远程管理和远程开关机。属于带外管理接口。
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The qtree security command changes the security style for files and directories. Security style means the method the filer uses to determine whether a user has access to a file. If name is the path name to a qtree, the security style applies to the files and directories in the specified qtree. The path name to a qtree does not need to end with a slash. If name is a path name to a volume, the security style applies to those directories and files in qtree 0. Any new qtree you create inherits the security style from qtree 0 by default. The path name to a volume must end with a slash.
The security style can be one of the following values:
unix
The user’s UID and GID, and the UNIX-style permission bits of the file or directory determine user access. The filer uses the same method for determining access for both NFS and CIFS requests. If you change the security style of a qtree or a volume from ntfs to unix, the filer disregards the Windows NT permissions that were established when the qtree or volume used the ntfs security style.
ntfs
For CIFS requests, Windows NT permissions determine user access. For NFS requests, the filer generates and stores a set of UNIX-style permission bits that are at least as restrictive as the Windows NT permissions. The filer grants NFS access only if the UNIX-style permission bits allow the user access. If you change the security style of a qtree or a volume from unix to ntfs, files created before the change do not have Windows NT permissions. For these files, the filer uses only the UNIX-style permission bits to determine access.
mixed
Some files in the qtree or volume have the unix security style, and some have the ntfs security style. A file’s security style depends on whether the permission was last set from CIFS or NFS. For example, if a file currently uses the unix security style and a CIFS user sends a setACL request to the file, the file’s security style is changed to ntfs. If a file currently uses the ntfs style and an NFS user sends a setpermission request to the file, the file’s security style is changed to unix.
If you do not specify unix, ntfs, or mixed in the qtree security command, the security style for name is displayed. - See more at:
http://www.wafl.co.uk/qtree/#sthash.NSrronT3.dpuf
1、如果windows系统使用qtree security style为ntfs的共享，那么可以在windows中直接对用户的访问权限进行更改。
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标识磁盘：
举例：0a.41即为Disk ID(磁盘标识)，Disk ID由path_id和device_id组成，即path_id,device_id的形式，通过Disk ID可快速定位磁盘的位置。
path_id指适配卡所在的槽位，和该适配器上的端口号，例如0a标识slot0上的适配器的拗口。
slot0一般是主板上集成的，slot上一般有a、b、c、d共4个端口，可在其他slot上附加适配卡，附加的适配卡一般是双端口的(a和b口)
device_id指磁盘的loop id或者scsi id号，由磁盘柜的ID号和该磁盘在磁盘柜中的位置(第几个bay)来决定。
另外，从sysconfig -r列出的磁盘信息：HA表示path_id；shelf表示盘柜的编号；bay表示该磁盘在盘柜中的位置。
参考链接：
http://blog.chinaunix.net/uid-70565-id-2070846.html
NetApp模拟器下载地址：
http://support.netapp.com/NOW/cgi-bin/simulator
软件下载地址：
http://mysupport.netapp.com/NOW/cgi-bin/software?product=OnCommand+System+Manager&platform=reload_main_page
本文转自daniel8294 51CTO博客，原文链接：http://blog.51cto.com/acadia627/1313461，如需转载请自行联系原作者
