All Questions
30
questions
0
votes
0
answers
1k
views
FIO 17x slower on ZFS than raw device
I have ZFS pool RAIDZ-1 on 4 x 3.84TB SATA3 'enterprise' SSDs.
zfs create rpool/fio
zfs set primarycache=none rpool/fio
fio --ioengine=sync --filename=[X] --direct=1 --rw=read --bs=4K --numjobs=1 --...
- 35
2
votes
0
answers
276
views
Running zfs trim twice on the same pool still takes forever the second time
I have this ZFS pool consisting of two mirrored 1TB Samsung 870 QVO drives, that I've been using for about a year for storing bhyve guest images as ZVOLs. During that time, I've created / messed with /...
- 121
3
votes
2
answers
720
views
What is the overhead of ZFS RAIDz1/2 in HPC SSD Environment?
Example hardware / host:
Modern 64 Core CPU, 128GB Memory
8 x Micron Pro 15.36TB u.2 SSDs
SSDs connected by dedicated Oculink per device (no backplane or PCIe sharing)
Ubuntu 20.04
Use case:
A ...
- 406
6
votes
3
answers
1k
views
How to overprovision an SSD for holding a smaller ZFS volume (ZVOL)?
I have a pair of 480 GB "Datacenter" SSDs (SAMSUNG MZ7LM480HMHQ-00005) that will make up a ZFS pool in a mirroring configuration. The pool's only content will be a ZFS volume (ZVOL) for a virtual ...
- 285
0
votes
1
answer
1k
views
fio numjobs & iodepth Values to Simulate Database PostgreSQL Workload?
I am trying to benchmark a ZFS RAID-10 array of SATA SSDs using fio with settings that are somewhat representative of database workloads like for PostgreSQL.
For example, for random reads:
fio --...
- 1,459
6
votes
1
answer
807
views
With a 500GB SSD and a 250GB SSD is it possible to mirror a 250GB partition on the 500GB with the 250GB SSD using ZFS?
So I have a Samsung 250GB 850 Evo SSD and a 500GB 860 EVO SSD. I'm looking at using Solaris for this server (so looking at whether doing this with ZFS is possible). Is it possible to mirror the 250GB ...
- 63
1
vote
2
answers
349
views
Lack of TRIM support -- will benchmarks get progressively slower on ZFS + SSD?
Context: I'm on a Toshiba 512 GB NVMe (Model: KXG50ZNV512G)
I'm seeing this weird behaviour while benchmarking Postgres on ZFS-on-Linux (via pgbench), where the second and third runs of a benchmark ...
- 489
5
votes
3
answers
7k
views
How to limit ZFS writes on NVME SSD in RAID1 to avoid rapid disk wear?
Currently I'm running Proxmox 5.3-7 on ZFS with few idling debian virtual machines. I'm using two SSDPE2MX450G7 NVME drives in RAID 1. After 245 days of running this setup the S.M.A.R.T values are ...
- 53
8
votes
1
answer
1k
views
Offline uncorrectable sectors in SSDs being used for ZFS L2ARC?
I have two enterprise-grade SSDs that I've been using for L2ARC in an OpenZFS pool for a few years. Workflow during this time has been fairly heavy, with lots of reads and writes, serving up video to ...
- 375
3
votes
4
answers
10k
views
ZFS: Configuration advice 1x NVMe as ARC and ZIL and 4x SSDs for zvols for virtualization
So recently upon testing a ZoL system we found out poor performance of random and sequential reads and poor performance of random writes on our SSDs.
Our system is a stripe of 2x Samsung 1TB 850Evo ...
- 61
2
votes
1
answer
226
views
In my ZFS box, why is my cache devices leaving a bunch of free space?
I have a ZFS system serving many VMs. In it, we installed 12x4TB SAS disks and configured them in a mirror. We added two PCI-E SSDs (Samsung 960s with 512GB each), but they are each consumed to just ...
- 296
5
votes
1
answer
871
views
Why is L2ARC not giving more speedup for directory traversal?
L2Arc is usually configured to cache random spinning platter reads on an SSD. I've set up this configuration in the hopes of speeding up directory traversal.
This is the setup:
# zpool list -v
NAME ...
5
votes
2
answers
1k
views
ZFS L2ARC for Mirror Pool
I was reading up on L2ARC for my ZFS. I currently have two Pools, One for Data, and the other for Linux Containers and Virtual Machines. I would like some help with L2ARC, I know how to add it but was ...
- 53
2
votes
2
answers
3k
views
Does the max-80%-use target suggested for ZFS for performance reasons apply to SSD-backed pools?
The Solaris ZFS Best Practices Guide recommends keeping ZFS pool utilization below 80% for best performance:
Keep pool space under 80% utilization to maintain pool performance. Currently, pool ...
- 4,375
5
votes
3
answers
2k
views
ZFS cksum errors on LSI 9207-9i (SAS2308) with Samsung 850 Pro SSDs
I am testing an LSI 9207-8i controller with 8x Samsung 850 Pro 256GB SSDs attached. SSDs are running latest firmware EXM02B6Q, controller is running P17 and has exhibited same issues with P19.
Server ...
3
votes
1
answer
1k
views
NexentaStor: how to partition SSD disk?
I'm trying to set up some homegrown storage using a desktop motherboard, 4 x SATA drives and 2 x SSD drives.
I'd really like to use NexentaStor for its nice web interface and for it is some ...
- 774
1
vote
1
answer
9k
views
Using SATA III SSDs for ZFS pools
I'm thinking of building a ZFS server optimized for random access (PostgreSQL database). I figured that I have 2 options:
Use pools consisting of the Crucial M500 960 GB SATA III SSDs. Enterprise SAS ...
- 389
3
votes
1
answer
557
views
FreeBSD 9.2 shows SATA3 drives as SATA2
I'm running FreeBSD 9.2 on an Intel S2600GZ server board with 4 Intel SSDs. Both the server board as well as the disks are SATA3 capable. However, FreeBSD seems to think they are SATA2. Nowhere in ...
- 286
25
votes
2
answers
33k
views
For L2ARC and ZIL: is it better to have one large SSD for both, or two smaller SSDs?
Main references
ZFS L2ARC (Brendan Gregg) (2008-07-22) and ZFS and the Hybrid Storage Concept (Anatol Studler's Blog) (2008-11-11) include the following diagram:
Question
Should I interpret the ...
- 635
1
vote
1
answer
2k
views
ZFS SSD Trim and Software Raid 5
I am trying to find if the ZFS filesystem has added support for Trim to Raid 5? I am setting up an SSD array in Raid 5. I also would like to know if there is any good software raid 5 alternatives to ...
- 13
3
votes
1
answer
3k
views
How do physical disks passed through ESXi perform vs. passing through HBAs?
Context:
I have a SAN operating system (Nexenta) that runs on ESXi. It has a couple of HBAs passed through to it already, via VT-d. All of the HBAs for the SAN OS are full (no free connectors). I ...
- 841
10
votes
3
answers
8k
views
ZFS - Impact of L2ARC cache device failure (Nexenta)
I have an HP ProLiant DL380 G7 server running as a NexentaStor storage unit.
The server has 36GB RAM, 2 LSI 9211-8i SAS controllers (no SAS expanders), 2 SAS system drives, 12 SAS data drives, a hot-...
- 197k
5
votes
2
answers
6k
views
ZFS: best practices for adding cache to pools
sounds like dumb question but there are no ready answers at SF
can the cache pool have different name than the zpool?
eg: suppose there is a zpool "tank" serving NFS and iSCSI
can a new cache pool ...
- 1,275
1
vote
2
answers
2k
views
how many disks can saturate a 6GSAS controller ? :LSI 9260-8i
This is my build:
LSI 9260-8i: MAX read throughput of 2,875 MB/s, write performance of 1,800 MB/s
24x SAS 10K RPM drives
2x 100GB Dell SSDR (SATA) drives for ZIL and L2ARC
All plugged to same ...
- 1,275
8
votes
2
answers
10k
views
What's in my ZFS ARC and L2ARC caches?
I have a simple ZFS setup at home, four disks mirrored, 8GB ram and 120GB Intel X25-M SSD for L2ARC. I ran zpool add poolname cache cXtXdX then generated load and eagerly tracked the warming process ...
- 3,515
5
votes
2
answers
5k
views
Will adding a SSD cache device to my ZFS storage improve performance?
The server has 4GB of RAM and my zpool is made up of 15.5k SAS drives arranged like this:
NAME STATE READ WRITE CKSUM
tank ONLINE 0 0 0
raidz1-0 ...
- 596
10
votes
2
answers
6k
views
ZFS and cache devices
I'm going to add a SSD drives to my ZFS storages as a cache. Anyone has any experience with this? What if cache device dies, will the any data be affected?
- 1,850
6
votes
2
answers
4k
views
ZFS with L2ARC (SSD) slower for random seeks than without L2ARC
I am currently testing ZFS (Opensolaris 2009.06) in an older fileserver to evaluate its use for our needs. Our current setup is as follows:
Dual core (2,4 GHz) with 4 GB RAM
3x SATA controller with ...
0
votes
7
answers
7k
views
ZFS - zpool ARC cache plus L2ARC benchmarking
I have been doing lots of I/O testing on a ZFS system I will eventually use to serve virtual machines. I thought I would try adding SSD's for use as cache to see how much faster I can get the read ...
- 304
1
vote
2
answers
2k
views
NTFS journal on different (SSD) disk
Some advanced file systems, like ZFS have the option of using SSD disks as a second level cache for the file system or for the journal.
Is this possible with NTFS?
- 368