Re: [zfs-discuss] Re: Re: ZFS or UFS - what to do?

2007-01-27 Thread Gary Mills
On Sat, Jan 27, 2007 at 04:15:30PM -0800, Anantha N. Srirama wrote: > > I'm not sure what benefit you forsee by running a COW filesystem > (ZFS) on a COW array (NetApp). Assuming that that question was addressed to me, the primary feature that I need from ZFS is snapshots. The Netapp has snapshot

Re: [zfs-discuss] Re: Re: ZFS or UFS - what to do?

2007-01-27 Thread Toby Thain
On 27-Jan-07, at 10:15 PM, Anantha N. Srirama wrote: ... ZFS will not stop alpha particle induced memory corruption after data has been received by server and verified to be correct. Sadly I've been hit with that as well. My brother points out that you can use a rad hardened CPU. ECC shou

Re: [zfs-discuss] Re: Re: ZFS or UFS - what to do?

2007-01-27 Thread Toby Thain
On 27-Jan-07, at 10:15 PM, Anantha N. Srirama wrote: We had in flight data corruption that EMC faithfully wrote just like NetApp would in your case. Everybody is assuming that corruption or data loss occurs only on disks, it can happen everywhere. In a datacenter SAN you've so many more pa

[zfs-discuss] Re: Re: ZFS or UFS - what to do?

2007-01-27 Thread Anantha N. Srirama
I'm not sure what benefit you forsee by running a COW filesystem (ZFS) on a COW array (NetApp). Back to regularly scheduled programming: I still say you should let ZFS manage JBoD type storage. I can personally recount the horror of relying upon an intelligent storage array (EMC DMX3500 in our

Re: [zfs-discuss] zfs rewrite?

2007-01-27 Thread Frank Cusack
On January 27, 2007 6:15:29 AM -0200 Toby Thain <[EMAIL PROTECTED]> wrote: On 27-Jan-07, at 4:57 AM, Frank Cusack wrote: On January 27, 2007 12:27:17 AM -0200 Toby Thain <[EMAIL PROTECTED]> wrote: On 26-Jan-07, at 11:34 PM, Pawel Jakub Dawidek wrote: 3. I created file system with huge amount

Re: [zfs-discuss] Re: ZFS or UFS - what to do?

2007-01-27 Thread David Magda
On Jan 26, 2007, at 14:43, Gary Mills wrote: Our Netapp does double-parity RAID. In fact, the filesystem design is remarkably similar to that of ZFS. Wouldn't that also detect the error? I suppose it depends if the `wrong sector without notice' error is repeated each time. Or is it random?

Re: [zfs-discuss] Re: ZFS or UFS - what to do?

2007-01-27 Thread David Magda
On Jan 26, 2007, at 14:05, Ed Gould wrote: It will work, but if the storage system corrupts the data, ZFS will be unable to correct it. It will detect the error. Unless you turn checksuming off. From zfs(1M): checksum=on | off | fletcher2, | fletcher4 | sha256 Controls the checksum used to

Re: [zfs-discuss] Re: high density SAS

2007-01-27 Thread Al Hopper
On Fri, 26 Jan 2007, Anton B. Rang wrote: > > > How badly can you mess up a JBOD? > > > > Two words: vibration, cooling. > > Three more: power, signal quality. > > I've seen even individual drive cases with bad enough signal quality to cause > bit errors. Yes - me too. I was a early adopter of

[zfs-discuss] Re: Adding my own compression to zfs

2007-01-27 Thread roland
is it planned to add some other compression algorithm to zfs ? lzjb is quite good and especially performing very well, but i`d like to have better compression (bzip2?) - no matter how worse performance drops with this. regards roland This message posted from opensolaris.org

Re: [zfs-discuss] Re: ZFS or UFS - what to do?

2007-01-27 Thread James C. McPherson
Selim Daoud wrote: it would be good to have real data and not only guess ot anecdots this story about wrong blocks being written by RAID controllers sounds like the anti-terrorism propaganda we are leaving in: exagerate the facts to catch everyone's attention .It's going to take more than that

Re: [zfs-discuss] zfs rewrite?

2007-01-27 Thread Toby Thain
On 27-Jan-07, at 4:57 AM, Frank Cusack wrote: On January 27, 2007 12:27:17 AM -0200 Toby Thain <[EMAIL PROTECTED]> wrote: On 26-Jan-07, at 11:34 PM, Pawel Jakub Dawidek wrote: 3. I created file system with huge amount of data, where most of the data is read-only. I change my server from inte