Re: [zfs-discuss] Does raidzN actually protect against bitrot? If yes - how?

2012-01-16 Thread Jim Klimov
Thanks again for answering! :) 2012-01-16 10:08, Richard Elling wrote: On Jan 15, 2012, at 7:04 AM, Jim Klimov wrote: Does raidzN actually protect against bitrot? That's a kind of radical, possibly offensive, question formula that I have lately. Simple answer: no. raidz provides data

Re: [zfs-discuss] zfs defragmentation via resilvering?

2012-01-16 Thread Jim Klimov
2012-01-16 8:39, Bob Friesenhahn wrote: On Sun, 15 Jan 2012, Edward Ned Harvey wrote: While I'm waiting for this to run, I'll make some predictions: The file is 2GB (16 Gbit) and the disk reads around 1Gbit/sec, so reading the initial sequential file should take ~16 sec After fragmentation, it

Re: [zfs-discuss] zfs defragmentation via resilvering?

2012-01-16 Thread Bob Friesenhahn
On Mon, 16 Jan 2012, Jim Klimov wrote: I think that in order to create a truly fragmented ZFS layout, Edward needs to do sync writes (without a ZIL?) so that every block and its metadata go to disk (coalesced as they may be) and no two blocks of the file would be sequenced on disk together.

Re: [zfs-discuss] zfs defragmentation via resilvering?

2012-01-16 Thread Gary Mills
On Mon, Jan 16, 2012 at 09:13:03AM -0600, Bob Friesenhahn wrote: On Mon, 16 Jan 2012, Jim Klimov wrote: I think that in order to create a truly fragmented ZFS layout, Edward needs to do sync writes (without a ZIL?) so that every block and its metadata go to disk (coalesced as they may be)

Re: [zfs-discuss] Apple's ZFS-alike - Re: Does raidzN actually protect against bitrot? If yes - how?

2012-01-16 Thread Rich Teer
On Sun, 15 Jan 2012, Toby Thain wrote: Rumours have long circulated, even before the brief public debacle of ZFS in OS X - is it in Leopard...yes it's in...no it's not...yes it's in...oh damn, it's really not - that Apple is building their own clone of ZFS. I don't know why APple don't just

Re: [zfs-discuss] Data loss by memory corruption?

2012-01-16 Thread David Magda
On Mon, January 16, 2012 01:19, Richard Elling wrote: [1] http://www.usenix.org/event/fast10/tech/full_papers/zhang.pdf Yes. Netapp has funded those researchers in the past. Looks like a FUD piece to me. Lookout everyone, the memory system you bought from Intel might suck! From the paper:

Re: [zfs-discuss] Apple's ZFS-alike - Re: Does raidzN actually protect against bitrot? If yes - how?

2012-01-16 Thread David Magda
On Mon, January 16, 2012 11:05, Rich Teer wrote: On Sun, 15 Jan 2012, Toby Thain wrote: Rumours have long circulated, even before the brief public debacle of ZFS in OS X - is it in Leopard...yes it's in...no it's not...yes it's in...oh damn, it's really not - that Apple is building their own

Re: [zfs-discuss] Apple's ZFS-alike - Re: Does raidzN actually protect against bitrot? If yes - how?

2012-01-16 Thread Bob Friesenhahn
On Mon, 16 Jan 2012, David Magda wrote: http://mail.opensolaris.org/pipermail/zfs-discuss/2009-October/033125.html Perhaps Apple can come to an agreement with Oracle when they couldn't with Sun. This seems very unlikely since the future needs of Apple show little requirement for zfs. Apple

Re: [zfs-discuss] Apple's ZFS-alike - Re: Does raidzN actually protect against bitrot? If yes - how?

2012-01-16 Thread Freddie Cash
On Mon, Jan 16, 2012 at 8:22 AM, Bob Friesenhahn bfrie...@simple.dallas.tx.us wrote: On Mon, 16 Jan 2012, David Magda wrote: http://mail.opensolaris.org/pipermail/zfs-discuss/2009-October/033125.html Perhaps Apple can come to an agreement with Oracle when they couldn't with Sun. This seems

Re: [zfs-discuss] Apple's ZFS-alike - Re: Does raidzN actually protect against bitrot? If yes - how?

2012-01-16 Thread Rich Teer
On Mon, 16 Jan 2012, Freddie Cash wrote: As an FS for their TimeMachine NAS boxes (Time Capsule, I think), though, ZFS would be a good fit. Similar to how the Time Slider works in Sun/Oracle's version of Nautilus/GNOME2. Especially if they expand the boxes to use 4 drives (2x mirror), and

Re: [zfs-discuss] Apple's ZFS-alike - Re: Does raidzN actually protect against bitrot? If yes - how?

2012-01-16 Thread Chris Ridd
On 16 Jan 2012, at 16:56, Rich Teer wrote: On Mon, 16 Jan 2012, Freddie Cash wrote: There would likely be a market if someone was to sell pre-packaged zfs for Apple OS-X at a much higher price than the operating system itself. 10's Complement (?) are planning such a thing, although I

Re: [zfs-discuss] Apple's ZFS-alike - Re: Does raidzN actually protect against bitrot? If yes - how?

2012-01-16 Thread David Magda
On Mon, January 16, 2012 11:22, Bob Friesenhahn wrote: This seems very unlikely since the future needs of Apple show little requirement for zfs. Apple only offers one computer model which provides ECC and a disk drive configuration which is marginally useful for zfs. This computer model has

Re: [zfs-discuss] Injection of ZFS snapshots into existing data, and replacement of older snapshots with zfs recv without truncating newer ones

2012-01-16 Thread Matthew Ahrens
On Thu, Jan 12, 2012 at 5:00 PM, Jim Klimov jimkli...@cos.ru wrote: While reading about zfs on-disk formats, I wondered once again why is it not possible to create a snapshot on existing data, not of the current TXG but of some older point-in-time? It is not possible because the older data

Re: [zfs-discuss] ZFS Upgrade

2012-01-16 Thread Matthew Ahrens
On Thu, Jan 5, 2012 at 7:17 PM, Ivan Rodriguez ivan...@gmail.com wrote: Dear list, I'm about to upgrade a zpool from 10 to 29 version, I suppose that this upgrade will improve several performance issues that are present on 10, however inside that pool we have several zfs filesystems all of

Re: [zfs-discuss] S11 vs illumos zfs compatiblity

2012-01-16 Thread Matthew Ahrens
On Thu, Jan 5, 2012 at 6:53 AM, sol a...@yahoo.com wrote: I would have liked to think that there was some good-will between the ex- and current-members of the zfs team, in the sense that the people who created zfs but then left Oracle still care about it enough to want the Oracle version to

Re: [zfs-discuss] Injection of ZFS snapshots into existing data, and replacement of older snapshots with zfs recv without truncating newer ones

2012-01-16 Thread Jim Klimov
2012-01-16 23:14, Matthew Ahrens пишет: On Thu, Jan 12, 2012 at 5:00 PM, Jim Klimov jimkli...@cos.ru mailto:jimkli...@cos.ru wrote: While reading about zfs on-disk formats, I wondered once again why is it not possible to create a snapshot on existing data, not of the current TXG but

Re: [zfs-discuss] L2ARC, block based or file based?

2012-01-16 Thread Matthew Ahrens
On Fri, Jan 13, 2012 at 4:49 PM, Matt Banks mattba...@gmail.com wrote: I'm sorry to be asking such a basic question that would seem to be easily found on Google, but after 30 minutes of googling and looking through this lists' archives, I haven't found a definitive answer. Is the L2ARC

Re: [zfs-discuss] Injection of ZFS snapshots into existing data, and replacement of older snapshots with zfs recv without truncating newer ones

2012-01-16 Thread Matthew Ahrens
On Mon, Jan 16, 2012 at 11:34 AM, Jim Klimov jimkli...@cos.ru wrote: 2012-01-16 23:14, Matthew Ahrens пишет: On Thu, Jan 12, 2012 at 5:00 PM, Jim Klimov jimkli...@cos.ru mailto:jimkli...@cos.ru wrote: While reading about zfs on-disk formats, I wondered once again why is it not

Re: [zfs-discuss] S11 vs illumos zfs compatiblity

2012-01-16 Thread sol
Thanks for that, Matt, very reassuring  :-) There is plenty of good will between everyone who's worked on ZFS -- current Oracle employees, former employees, and those never employed by Oracle.  We would all like to see all implementations of ZFS be the

Re: [zfs-discuss] Data loss by memory corruption?

2012-01-16 Thread John Martin
On 01/16/12 11:08, David Magda wrote: The conclusions are hardly unreasonable: While the reliability mechanisms in ZFS are able to provide reasonable robustness against disk corruptions, memory corruptions still remain a serious problem to data integrity. I've heard the same thing said (use