In general, mixing SATA and SAS directly behind expanders (eg without
SAS/SATA intereposers) seems to be bad juju that an OS can't fix.
In general I'd agree. Just mixing them on the same box can be problematic,
I've noticed - though I think as much as anything that the firmware
on the 3G/s
On Mar 25, 2012, at 6:26 AM, Jeff Bacon wrote:
In general, mixing SATA and SAS directly behind expanders (eg without
SAS/SATA intereposers) seems to be bad juju that an OS can't fix.
In general I'd agree. Just mixing them on the same box can be problematic,
I've noticed - though I think as
2012-03-21 16:41, Paul Kraus wrote:
I have been running ZFS in a mission critical application since
zpool version 10 and have not seen any issues with some of the vdevs
in a zpool full while others are virtually empty. We have been running
commercial Solaris 10 releases. The
Thanks for sharing, Jeff!
Comments below...
On Mar 24, 2012, at 4:33 PM, Jeff Bacon wrote:
2012-03-21 16:41, Paul Kraus wrote:
I have been running ZFS in a mission critical application since
zpool version 10 and have not seen any issues with some of the vdevs
in a zpool full while others
2012-03-21 22:53, Richard Elling wrote:
...
This is why a single
vdev's random-read performance is equivalent to the random-read
performance of
a single drive.
It is not as bad as that. The actual worst case number for a HDD with
zfs_vdev_max_pending
of one is:
average IOPS * ((D+P) / D)
From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss-
boun...@opensolaris.org] On Behalf Of Paul Kraus
Three are two different cases here... resilver to reconstruct
data from a failed drive and a scrub to pro-actively find bad sectors.
The best case situation for the
From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss-
boun...@opensolaris.org] On Behalf Of maillist reader
I read though that ZFS does not have a defragmentation tool, is this
still the
case?
True.
It would seem with such a performance difference between
sequential reads and
On Mar 22, 2012, at 3:03 AM, Jim Klimov wrote:
2012-03-21 22:53, Richard Elling wrote:
...
This is why a single
vdev's random-read performance is equivalent to the random-read
performance of
a single drive.
It is not as bad as that. The actual worst case number for a HDD with
2012-03-22 20:52, Richard Elling wrote:
Yes, but it is a rare case for 512b sectors.
It could be more common for 4KB sector disks when ashift=12.
...
Were there any research or tests regarding storage of many small
files (1-sector sized or close to that) on different vdev layouts?
It is not
On Thu, 22 Mar 2012, Jim Klimov wrote:
I think that a certain Bob F. would disagree, especially
when larger native sectors and ashist=12 come into play.
Namely, one scenario where this is important is automated
storage of thumbnails for websites, or some similar small
objects in vast amounts.
2012-03-21 7:16, MLR wrote:
I read the ZFS_Best_Practices_Guide and ZFS_Evil_Tuning_Guide, and have some
questions:
1. Cache device for L2ARC
Say we get a decent ssd, ~500MB/s read/write. If we have a 20 HDD zpool
setup shouldn't we be reading at least at the 500MB/s read/write range?
On Wed, Mar 21, 2012 at 7:56 AM, Jim Klimov jimkli...@cos.ru wrote:
2012-03-21 7:16, MLR wrote:
One thing to note is that many people would not recommend using
a disbalanced ZFS array - one expanded by adding a TLVDEV after
many writes, or one consisting of differently-sized TLVDEVs.
ZFS
2012-03-21 16:41, Paul Kraus wrote:
I have been running ZFS in a mission critical application since
zpool version 10 and have not seen any issues with some of the vdevs
in a zpool full while others are virtually empty. We have been running
commercial Solaris 10 releases. The configuration
From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss-
boun...@opensolaris.org] On Behalf Of MLR
Say we get a decent ssd, ~500MB/s read/write. If we have a 20 HDD
zpool
setup shouldn't we be reading at least at the 500MB/s read/write range?
Why
would we want a ~500MB/s cache?
On Tue, Mar 20, 2012 at 11:16 PM, MLR maillistread...@gmail.com wrote:
1. Cache device for L2ARC
Say we get a decent ssd, ~500MB/s read/write. If we have a 20 HDD zpool
setup shouldn't we be reading at least at the 500MB/s read/write range? Why
would we want a ~500MB/s cache?
2012-03-21 17:28, Edward Ned Harvey wrote:
From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss-
boun...@opensolaris.org] On Behalf Of MLR
...
Am I correct in thinking this means, for example, I have a single
14 disk raidz2 vdev zpool,
It's not advisable to put more than ~8 disks
On Wed, Mar 21, 2012 at 9:51 AM, Jim Klimov jimkli...@cos.ru wrote:
2012-03-21 17:28, Edward Ned Harvey wrote:
It's not advisable to put more than ~8 disks in a single vdev, because it
really hurts during resilver time. Maybe a week or two to resilver like
that.
Yes, that's important to
p...@kraus-haus.org said:
Without knowing the I/O pattern, saying 500 MB/sec. is meaningless.
Achieving 500MB/sec. with 8KB files and lots of random accesses is really
hard, even with 20 HDDs. Achieving 500MB/sec. of sequential streaming of
100MB+ files is much easier.
. . .
For ZFS,
2012-03-21 21:40, Marion Hakanson цкщеу:
Small, random read performance does not scale with the number of drives in each
raidz[123] vdev because of the dynamic striping. In order to read a single
logical block, ZFS has to read all the segments of that logical block, which
have been spread out
comments below...
On Mar 21, 2012, at 10:40 AM, Marion Hakanson wrote:
p...@kraus-haus.org said:
Without knowing the I/O pattern, saying 500 MB/sec. is meaningless.
Achieving 500MB/sec. with 8KB files and lots of random accesses is really
hard, even with 20 HDDs. Achieving 500MB/sec. of
Thank you all for the information, I believe it is much clearer to me.
Sequential Reads should scale with the number of disks in the entire
zpool (regardless of amount of vdevs), and Random Reads will scale with
just the number of vdevs (aka idea I had before only applies to Random
Reads), which I
I read the ZFS_Best_Practices_Guide and ZFS_Evil_Tuning_Guide, and have
some
questions:
1. Cache device for L2ARC
Say we get a decent ssd, ~500MB/s read/write. If we have a 20 HDD zpool
setup shouldn't we be reading at least at the 500MB/s read/write range? Why
would we want a ~500MB/s
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