[zfs-discuss] How does dedup work over iSCSI?

2010-10-22 Thread Peter Taps
Folks, Let's say I have a volume being shared over iSCSI. The dedup has been turned on. Let's say I copy the same file twice under different names at the initiator end. Let's say each file ends up taking 5 blocks. For dedupe to work, each block for a file must match the corresponding block

Re: [zfs-discuss] How does dedup work over iSCSI?

2010-10-22 Thread Neil Perrin
On 10/22/10 15:34, Peter Taps wrote: Folks, Let's say I have a volume being shared over iSCSI. The dedup has been turned on. Let's say I copy the same file twice under different names at the initiator end. Let's say each file ends up taking 5 blocks. For dedupe to work, each block for a file

Re: [zfs-discuss] How does dedup work over iSCSI?

2010-10-22 Thread Peter Taps
Hi Neil, if the file offset does not match, the chances that the checksum would match, especially sha256, is almost 0. May be I am missing something. Let's say I have a file that contains 11 letters - ABCDEFGHIJK. Let's say the block size is 5. For the first file, the block contents are

Re: [zfs-discuss] How does dedup work over iSCSI?

2010-10-22 Thread Neil Perrin
On 10/22/10 17:28, Peter Taps wrote: Hi Neil, if the file offset does not match, the chances that the checksum would match, especially sha256, is almost 0. May be I am missing something. Let's say I have a file that contains 11 letters - ABCDEFGHIJK. Let's say the block size is 5. For the

Re: [zfs-discuss] How does dedup work over iSCSI?

2010-10-22 Thread Haudy Kazemi
Neil Perrin wrote: On 10/22/10 15:34, Peter Taps wrote: Folks, Let's say I have a volume being shared over iSCSI. The dedup has been turned on. Let's say I copy the same file twice under different names at the initiator end. Let's say each file ends up taking 5 blocks. For dedupe to