Hello fellow toaster-ites! I am evaluating the use of NFS datastore on NetApp for use with ESX. Initially the potential benefits of ASIS (dedup) had me just about sold, however, I discovered that with the FAS2020 we're looking at there is a 500GB limit to the size of ASIS enabled FlexVols. Bummer.
I see this limit goes up to 1TB with the FAS2050, so I may need to compare that option as well...
Moreover, I'm wondering what the limit on the *number* of max-sized ASIS enabled flexvols is per filer? Could I have 15 500GB ASIS enabled flexvols in the FAS2020 above? That wouldn't seem to make logical sense as I understand the limitation is tied to memory.... but this might help us get around this size limitation.
Thanks in advance.
(No sales replies to this please)
Ray
I do not think there is a limit, but before rolling out ASIS on your primary storage you should look into the bug that makes sequential data reads on VMDK files EXTREMELY slow. It's killing our production system and no end dates yet for a patch.
Bug ID 281669
NDMP/NFS reads on dense VMware files could encounter slow access. This is because the portion of the VMDK file that has not been allocated by the guest OS is filled with zeros. Activities that are likely to be affected are the use of tools which read the entire VMDK file (such as cp from the ESX console and dump from the FAS systems). Normal guest performance will not be effected.
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Ray Van Dolson Sent: Tuesday, October 21, 2008 1:30 PM To: toasters@mathworks.com Subject: Limits on ASIS enabled FlexVols
Hello fellow toaster-ites! I am evaluating the use of NFS datastore on NetApp for use with ESX. Initially the potential benefits of ASIS (dedup) had me just about sold, however, I discovered that with the FAS2020 we're looking at there is a 500GB limit to the size of ASIS enabled FlexVols. Bummer.
I see this limit goes up to 1TB with the FAS2050, so I may need to compare that option as well...
Moreover, I'm wondering what the limit on the *number* of max-sized ASIS enabled flexvols is per filer? Could I have 15 500GB ASIS enabled flexvols in the FAS2020 above? That wouldn't seem to make logical sense as I understand the limitation is tied to memory.... but this might help us get around this size limitation.
Thanks in advance.
(No sales replies to this please)
Ray
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The ASIS volume size limits go away in 7.3.1, so if you can get by with the current limits for now, you can grow the volumes later.
I don't know if there is a limit to the number of ASIS volumes on a filer. I know there are limits to the number of active ASIS processes, but if you hit that, they just run in sequence like when the snapmirror/snapvault concurrent limits are hit.
John
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Ray Van Dolson Sent: Tuesday, October 21, 2008 10:30 AM To: toasters@mathworks.com Subject: Limits on ASIS enabled FlexVols
Hello fellow toaster-ites! I am evaluating the use of NFS datastore on NetApp for use with ESX. Initially the potential benefits of ASIS (dedup) had me just about sold, however, I discovered that with the FAS2020 we're looking at there is a 500GB limit to the size of ASIS enabled FlexVols. Bummer.
I see this limit goes up to 1TB with the FAS2050, so I may need to compare that option as well...
Moreover, I'm wondering what the limit on the *number* of max-sized ASIS enabled flexvols is per filer? Could I have 15 500GB ASIS enabled flexvols in the FAS2020 above? That wouldn't seem to make logical sense as I understand the limitation is tied to memory.... but this might help us get around this size limitation.
Thanks in advance.
(No sales replies to this please)
Ray
On Tue, Oct 21, 2008 at 12:57:19PM -0700, Clear, John wrote:
The ASIS volume size limits go away in 7.3.1, so if you can get by with the current limits for now, you can grow the volumes later.
This sounds promising. I'll try and confirm with NetApp -- you don't happen to have a NOW document link referencing this in the roadmap by chance do you?
I don't know if there is a limit to the number of ASIS volumes on a filer. I know there are limits to the number of active ASIS processes, but if you hit that, they just run in sequence like when the snapmirror/snapvault concurrent limits are hit.
From what I've found out, it looks like (at least on the FAS2020) we can have 8 simultaneous dedup threads running -- but there is no limit to the number of ASIS enabled volumes.
So, pretty much what you said -- the dedup jobs just get queueed up.
John
Thanks! Ray
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Clear, John -
Page, Jeremy -
Ray Van Dolson