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Questions tagged [zfs-l2arc]

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7
votes
1answer
404 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 ...
2
votes
1answer
51 views

How should I use the new Optum drive?

I have a zpool consisting of 7 2TB HDDs of different vintage in a raidz setup. Currently, there is neither ZIL nor L2ARC device configured. The server has 12GB of RAM and no swap. The different ...
2
votes
1answer
56 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 ...
3
votes
1answer
200 views

Tracing what blocks go through L2ARC in ZFS on Solaris using dtrace

My colleague and myself are trying to trace the reads/writes to the L2ARC in OpenZFS. We want the block offsets, IO type (read/write) and the device-ids of the requests. Note that we don't want the ...
1
vote
1answer
511 views

ZFS on Linux and KVM: NUMA nodes for host

I am interested in using KVM images on zvols under ZFS on Linux, on a multi-socket system. I am wondering how I should pin NUMA nodes so as to maximize the benefits of ZFS ARC cache for all KVM images ...
5
votes
2answers
901 views

Priming a ZFS L2ARC cache on Solaris 11.3

Is there a good way to prime a ZFS L2ARC cache on Solaris 11.3? The L2ARC is designed to ignore blocks that have been read sequentially from a file. This makes sense for ongoing operation but makes ...
1
vote
2answers
7k views

freenas zfs read performance sucks .. why?

I just set up a freenas zfs raid-z2 with 4 drives sata enterprise drives and doing some performance tests. Right now I'm pushing and pulling linux images into the storage. My notebook has a samsung ...
1
vote
1answer
6k 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 ...
3
votes
2answers
2k views

size the write cache ZFS

I would like to add a write cache to my Nexenta. I thought about using 2 SSDs in mirror with a third disc in spare. The problem is: How do I calculate the size of my array to maximize the investment (...
1
vote
1answer
728 views

How to fetch current l2arc_max_write setting on Illumos?

I am trying to tweak my ZFS pool, but in order to do this I would like to know the current l2arc_max_write setting. I know the default is 8 MB/s, but I can't find the actual value. I have tried to ...
2
votes
4answers
10k views

Will a SSD cache increase Native ZFS performance for me?

I'm using Ubuntu 11.10 Desktop x64 with Native ZFS using a mirrored pool of 2x2 TB 6.0 Gbps hard drives. My issue is that I'm only getting about 30 Mb/s read/write at any time, I would think my system ...
6
votes
1answer
3k views

Solaris ZFS volumes: workload not hitting L2ARC

I've set up a Solaris Express 11 machine with some reasonably fast HDDs behind a RAID controller, set the device up as a zpool with compression enabled and added a mirrored log and 2 caching devices ...
10
votes
3answers
6k 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-...
1
vote
3answers
2k views

Where is my free memory? (Solaris 10)

I have a default Solaris 10 installation running on a 64GB box. For some reason, not all of the memory is available for use. The reason I'm even bothered by it, is because I'm trying to get mysql to ...
7
votes
2answers
6k 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 ...