Re: [zfs-discuss] Pure SSD Pool

2011-07-16 Thread Eric D. Mudama
On Tue, Jul 12 at 23:44, Jim Klimov wrote: 2011-07-12 23:14, Eric Sproul пишет: So finding drives that keep more space in reserve is key to getting consistent performance under ZFS. I think I've read in a number of early SSD reviews (possibly regarding Intel devices - not certain now) that the

Re: [zfs-discuss] Pure SSD Pool

2011-07-12 Thread Orvar Korvar
I am now using S11E and a OCZ Vertex 3, 240GB SSD disk. I am using it in a SATA 2 port (not the new SATA 6gbps). The PC seems to work better now, the worst lag is gone. For instance, I am using Sunray, and if my girl friend is using the PC, and I am doing bit torrenting, the PC could lock up f

Re: [zfs-discuss] Pure SSD Pool

2011-07-12 Thread Jim Klimov
2011-07-12 23:14, Eric Sproul пишет: So finding drives that keep more space in reserve is key to getting consistent performance under ZFS. I think I've read in a number of early SSD reviews (possibly regarding Intel devices - not certain now) that the vendor provided some low-level formatting t

Re: [zfs-discuss] Pure SSD Pool

2011-07-12 Thread Brandon High
On Tue, Jul 12, 2011 at 12:14 PM, Eric Sproul wrote: > I see, thanks for that explanation.  So finding drives that keep more > space in reserve is key to getting consistent performance under ZFS. More spare area might give you more performance, but the big difference is the lifetime of the device

Re: [zfs-discuss] Pure SSD Pool

2011-07-12 Thread Eric Sproul
On Tue, Jul 12, 2011 at 1:35 PM, Brandon High wrote: > Most "enterprise" SSDs use something like 30% for spare area. So a > drive with 128MiB (base 2) of flash will have 100MB (base 10) of > available storage. A consumer level drive will have ~ 6% spare, or > 128MiB of flash and 128MB of available

Re: [zfs-discuss] Pure SSD Pool

2011-07-12 Thread Brandon High
On Tue, Jul 12, 2011 at 7:41 AM, Eric Sproul wrote: > But that's exactly the problem-- ZFS being copy-on-write will > eventually have written to all of the available LBA addresses on the > drive, regardless of how much live data exists.  It's the rate of > change, in other words, rather than the a

Re: [zfs-discuss] Pure SSD Pool

2011-07-12 Thread Erik Trimble
but RAID is still a problem for TRIM at the OS level. > > Henry > > > > - Original Message > From: Jim Klimov > Cc: ZFS Discussions > Sent: Tue, July 12, 2011 4:18:28 AM > Subject: Re: [zfs-discuss] Pure SSD Pool > > 2011-07-12 9:06, Brandon High пише

Re: [zfs-discuss] Pure SSD Pool

2011-07-12 Thread Henry Lau
from ZFS level should be a better solution but RAID is still a problem for TRIM at the OS level. Henry - Original Message From: Jim Klimov Cc: ZFS Discussions Sent: Tue, July 12, 2011 4:18:28 AM Subject: Re: [zfs-discuss] Pure SSD Pool 2011-07-12 9:06, Brandon High пишет: > On

Re: [zfs-discuss] Pure SSD Pool

2011-07-12 Thread Garrett D'Amore
I think high end SSDs, like those from Pliant, use a significant amount of "over allocation", and internal remapping and internal COW, so that they can automatically garbage collect when they need to, without TRIM. This only works if the drive has enough extra free space that it knows about (be

Re: [zfs-discuss] Pure SSD Pool

2011-07-12 Thread Bob Friesenhahn
On Tue, 12 Jul 2011, Eric Sproul wrote: Now, others have hinted that certain controllers are better than others in the absence of TRIM, but I don't see how GC could know what blocks are available to be erased without information from the OS. Drives which keep spare space in reserve (as any res

Re: [zfs-discuss] Pure SSD Pool

2011-07-12 Thread Eric Sproul
On Tue, Jul 12, 2011 at 1:06 AM, Brandon High wrote: > On Mon, Jul 11, 2011 at 7:03 AM, Eric Sproul wrote: >> Interesting-- what is the suspected impact of not having TRIM support? > > There shouldn't be much, since zfs isn't changing data in place. Any > drive with reasonable garbage collection

Re: [zfs-discuss] Pure SSD Pool

2011-07-12 Thread Fajar A. Nugraha
On Tue, Jul 12, 2011 at 6:18 PM, Jim Klimov wrote: > 2011-07-12 9:06, Brandon High пишет: >> >> On Mon, Jul 11, 2011 at 7:03 AM, Eric Sproul  wrote: >>> >>> Interesting-- what is the suspected impact of not having TRIM support? >> >> There shouldn't be much, since zfs isn't changing data in place.

Re: [zfs-discuss] Pure SSD Pool

2011-07-12 Thread Jim Klimov
2011-07-12 9:06, Brandon High пишет: On Mon, Jul 11, 2011 at 7:03 AM, Eric Sproul wrote: Interesting-- what is the suspected impact of not having TRIM support? There shouldn't be much, since zfs isn't changing data in place. Any drive with reasonable garbage collection (which is pretty much ev

Re: [zfs-discuss] Pure SSD Pool

2011-07-11 Thread Brandon High
On Mon, Jul 11, 2011 at 7:03 AM, Eric Sproul wrote: > Interesting-- what is the suspected impact of not having TRIM support? There shouldn't be much, since zfs isn't changing data in place. Any drive with reasonable garbage collection (which is pretty much everything these days) should be fine un

Re: [zfs-discuss] Pure SSD Pool

2011-07-11 Thread Eric Sproul
On Sat, Jul 9, 2011 at 2:19 PM, Roy Sigurd Karlsbakk wrote: > Most drives should work well for a pure SSD pool. I have a postgresql > database on a linux box on a mirrored set of C300s. AFAIK ZFS doesn't yet > support TRIM, so that can be an issue. Apart from that, it should work well. Interest

Re: [zfs-discuss] Pure SSD Pool

2011-07-09 Thread Roy Sigurd Karlsbakk
> I have a dual xeon 64GB 1U server with two free 3.5" drive slots. I > also have a free PCI-E slot. > > I'm going to run a postgress database with a business intelligence > application. > > The database size is not really set. It will be between 250-500GB > running on Solaris 10 or b134. Runnin