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| Post | Author | Url | Body | ||||
|---|---|---|---|---|---|---|---|
| zil_disable | Cal | cal@fbsdata.com | GREAT article. I've been battling Sun support for almost 5 months to get this information! After several escalations I reached the right person to point me in the right direction. This page needs a better Google PageRank! | Show | Edit | Destroy | |
| zil_disable | Dave | happy@user.com | Bad Idea... The /etc/system parameter, zil_disable=1 disables synchronous writes to NFS file systems. As with all asynchronous writes, if there is a failure transient, the possibility of data loss exists. It has been observed that there may be file system performance improvement, but this is at the expense of data integrity. zil_disable is an undocumented feature and will be abandoned in future releases of ZFS. For this reason, designs should not incorporate the use of this feature. See http://blogs.sun.com/erickustarz/entry/zil_disable for more information. | Show | Edit | Destroy | |
| zil_disable | Jeremy | jeremy.thornhill@gmail.com | I'm surprised to see recent activity on this post. Cal: glad I could help. There's not a lot of information on this in the wild, so I considered myself pretty lucky to stumble upon some. Dave: You'll notice I linked to that entry already in my post, and I'm not going to claim to you that this is 100% safe to use in all cases. The important consideration here is that: 1) the ZFS filesystem itself will NOT be compromised due to zil disable 2) the NFS <i>client</i> may have its view corrupted in the event of a NFS server failure. As Eric Kustarz mentioned in his original entry: <i>Disabling the ZIL can cause corruption for NFS clients in the case where a reply to the client is done before the server crashes, and the server crashes before the data is commited to stable storage. If you can't live with this, then don't turn off the ZIL. </i> Now that really should be a pretty rare occurance (NFS server crash while a write is pending), but disabling the zil introduces the <i>possibility</i> of corrupting the client's state in such an event. As he says... if you can't live with it, don't turn off the zil! :) | Show | Edit | Destroy |
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