Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-25 Thread Roch Bourbonnais
Le 23 oct. 08 à 05:40, Constantin Gonzalez a écrit : > Hi, > > Bob Friesenhahn wrote: >> On Wed, 22 Oct 2008, Neil Perrin wrote: >>> On 10/22/08 10:26, Constantin Gonzalez wrote: 3. Disable ZIL[1]. This is of course evil, but one customer pointed out to me that if a tar xvf we

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-23 Thread Ross Smith
No problem. I didn't use mirrored slogs myself, but that's certainly a step up for reliability. It's pretty easy to create a boot script to re-create the ramdisk and re-attach it to the pool too. So long as you use the same device name for the ramdisk you can add it each time with a simple "zpoo

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-23 Thread Bob Friesenhahn
On Thu, 23 Oct 2008, Constantin Gonzalez wrote: > > This is what the customer told me. He uses rsync and he is ok with restarting > the rsync whenever the NFS server restarts. Then remind your customer to tell rsync to inspect the data rather than trusting time stamps. Rsync will then run quite

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-23 Thread Constantin Gonzalez
Hi, Bob Friesenhahn wrote: > On Thu, 23 Oct 2008, Constantin Gonzalez wrote: >> >> Yes, we're both aware of this. In this particular situation, the customer >> would restart his backup job (and thus the client application) in case >> the >> server dies. > > So it is ok for this customer if their

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-23 Thread Bob Friesenhahn
On Thu, 23 Oct 2008, Constantin Gonzalez wrote: > > Yes, we're both aware of this. In this particular situation, the customer > would restart his backup job (and thus the client application) in case the > server dies. So it is ok for this customer if their backup becomes silently corrupted and th

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-23 Thread Constantin Gonzalez
Hi, yes, using slogs is the best solution. Meanwhile, using mirrored slogs from other servers' RAM-Disks running on UPSs seem like an interesting idea, if the reliability of UPS-backed RAM is deemed reliable enough for the purposes of the NFS server. Thanks for siggesting this! Cheers, Cons

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-23 Thread Constantin Gonzalez
Hi, Bob Friesenhahn wrote: > On Wed, 22 Oct 2008, Neil Perrin wrote: >> On 10/22/08 10:26, Constantin Gonzalez wrote: >>> 3. Disable ZIL[1]. This is of course evil, but one customer pointed out to >>> me >>> that if a tar xvf were writing locally to a ZFS file system, the writes >>> would

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-23 Thread Constantin Gonzalez
Hi, >> - The ZIL exists on a per filesystem basis in ZFS. Is there an RFE >> already >>that asks for the ability to disable the ZIL on a per filesystem >> basis? > > Yes: 6280630 zil synchronicity good, thanks for the pointer! > Though personally I've been unhappy with the exposure that z

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-22 Thread Richard Elling
Ricardo M. Correia wrote: > Hi Richard, > > On Qua, 2008-10-22 at 14:04 -0700, Richard Elling wrote: > >> It is more important to use a separate disk, than to use a separate and fast >> disk. Anecdotal evidence suggests that using a USB hard disk works >> well. >> > > While I don't necessa

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-22 Thread Ricardo M. Correia
Hi Richard, On Qua, 2008-10-22 at 14:04 -0700, Richard Elling wrote: > It is more important to use a separate disk, than to use a separate and fast > disk. Anecdotal evidence suggests that using a USB hard disk works > well. While I don't necessarily disagree with your statement, please note tha

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-22 Thread Nicolas Williams
On Wed, Oct 22, 2008 at 04:46:00PM -0400, Miles Nordin wrote: > I thought NFSv2 -> NFSv3 was supposed to make this prestoserv, SSD, > battery-backed DRAM stuff not needed for good performance any more. I > guess not though. There are still a number of operations in NFSv3 and NFSv4 which the clien

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-22 Thread Richard Elling
Constantin Gonzalez wrote: > Hi, > > On a busy NFS server, performance tends to be very modest for large amounts > of small files due to the well known effects of ZFS and ZIL honoring the > NFS COMMIT operation[1]. > > For the mature sysadmin who knows what (s)he does, there are three > possibiliti

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-22 Thread Bob Friesenhahn
On Wed, 22 Oct 2008, Miles Nordin wrote: > > I thought NFSv2 -> NFSv3 was supposed to make this prestoserv, SSD, > battery-backed DRAM stuff not needed for good performance any more. I > guess not though. The intent was to allow the server to be able to buffer up more uncommitted data before the

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-22 Thread Miles Nordin
> "cg" == Constantin Gonzalez <[EMAIL PROTECTED]> writes: cg> if a tar xvf were writing locally to a ZFS file system, the cg> writes wouldn't be synchronous either, so there's no point in cg> forcing NFS users to having a better It's worse for NFS because breaking the commit/lease

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-22 Thread Neil Perrin
On 10/22/08 13:56, Marcelo Leal wrote: >>> But the slog is the ZIL. formaly a *separate* >> intent log. >> >> No the slog is not the ZIL! > Ok, when you did write this: > "I've been slogging for a while on support for separate intent logs (slogs) > for ZFS. > Without slogs, the ZIL is allocated

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-22 Thread Marcelo Leal
> > But the slog is the ZIL. formaly a *separate* > intent log. > > No the slog is not the ZIL! Ok, when you did write this: "I've been slogging for a while on support for separate intent logs (slogs) for ZFS. Without slogs, the ZIL is allocated dynamically from the main pool". You were talki

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-22 Thread Neil Perrin
> But the slog is the ZIL. formaly a *separate* intent log. No the slog is not the ZIL! Here's the definition of the terms as we've been trying to use them: ZIL: The body of code the supports synchronous requests, which writes out to the Intent Logs Intent Log: A stable s

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-22 Thread Bill Sommerfeld
On Wed, 2008-10-22 at 10:45 -0600, Neil Perrin wrote: > Yes: 6280630 zil synchronicity > > Though personally I've been unhappy with the exposure that zil_disable has > got. > It was originally meant for debug purposes only. So providing an official > way to make synchronous behaviour asynchronous

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-22 Thread Marcelo Leal
> Bah, I've done it again. I meant use it as a slog > device, not as the ZIL... But the slog is the ZIL. formaly a *separate* intent log. What´s the matter? I think everyone did understand. I think you did make a confusion some threads before about ZIL and L2ARC. That is a different thing.. ;-)

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-22 Thread Ross
Bah, I've done it again. I meant use it as a slog device, not as the ZIL... I'll get this terminology in my head eventually. -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-22 Thread Ross
Well, it might be even more of a bodge than disabling the ZIL, but how about: - Create a 512MB ramdisk, use that for the ZIL - Buy a Micro Memory nvram PCI card for £100 or so. - Wait 3-6 months, hopefully buy a fully supported PCI-e SSD to replace the Micro Memory card. The ramdisk isn't an ide

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-22 Thread Marcelo Leal
I agree with you Constantin that the sync is a performance problem, in the same way i think in a NFS environment it is just *required*. If the sync can be relaxed in a "specific NFS environment", my first opinion is that the NFS is not necessary on that environment in first place. IMHO a proto

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-22 Thread Bob Friesenhahn
On Wed, 22 Oct 2008, Neil Perrin wrote: > > On 10/22/08 10:26, Constantin Gonzalez wrote: >> 3. Disable ZIL[1]. This is of course evil, but one customer pointed out to me >> that if a tar xvf were writing locally to a ZFS file system, the writes >> wouldn't be synchronous either, so there's

Re: [zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-22 Thread Neil Perrin
On 10/22/08 10:26, Constantin Gonzalez wrote: > Hi, > > On a busy NFS server, performance tends to be very modest for large amounts > of small files due to the well known effects of ZFS and ZIL honoring the > NFS COMMIT operation[1]. > > For the mature sysadmin who knows what (s)he does, there

[zfs-discuss] Disabling COMMIT at NFS level, or disabling ZIL on a per-filesystem basis

2008-10-22 Thread Constantin Gonzalez
Hi, On a busy NFS server, performance tends to be very modest for large amounts of small files due to the well known effects of ZFS and ZIL honoring the NFS COMMIT operation[1]. For the mature sysadmin who knows what (s)he does, there are three possibilities: 1. Live with it. Hard, if you see 10