Hosting on Solaris instead of FreeBSD

Hosting webapps on Solaris instead of FreeBSD? Why not :) Looks like that is exactly what Joyent is going to do. Look at this pdf - how they consolidate on Niagara boxes, use zones, zfs, etc.

Software RAID-5 faster than RAID-10

Software RAID-5 solutions were always much slower in writing data than RAID-10. However ZFS completely changes that picture. Lets say we've got 4 disks - with all the other software RAID solutions when you create RAID-5 from these 5 disks then writing to them will be MUCH slower than if you created RAID-10. But if you create RAID-5 (in ZFS called RAID-Z) from these 5 disks the you will see that writing performance is actually much better then RAID-10.
I did such a test today with 4 disks and sequential writing to different RAID levels using ZFS and 'dd' command.

ZFS RAID                   ##  write in MB/s
#############################################

RAID-10   (mirror+stripe)  ##   117MB/s
RAID-Z    (RAID-5)         ##   175MB/s
RAID-0    (striping)       ##   233MB/s

In theory ZFS in this test (writing) should give us the performance of two disks in case of RAID-10, the performance of 3 disks in case of RAID-Z and the performance of 4 disks in case of RAID-0. And that's exactly what we see above! (117/2 = 58.5000 ; 175/3 = 58.3333 ; 233/4 =58.2500).

MySQL on Solaris faster than on Linux?

Yahoo reports that MySQL on Solaris is faster than on Linux.

SANTA CLARA, Calif., April 21 /PRNewswire-FirstCall/ -- Sun Microsystems, Inc. (Nasdaq: SUNW - News) today announced new benchmark results involving the performance of the open source MySQL database running online transaction processing (OLTP) workload on 8-way Sun Fire(TM) V40z servers. The testing, which measured the performance of both read/write and read-only operations, showed that MySQL 5.0.18 running on the Solaris(TM) 10 Operating System (OS) executed the same functions up to 64 percent faster in read/write mode and up to 91 percent faster in read-only mode than when it ran on the Red Hat Enterprise Linux 4 Advanced Server Edition OS.

"MySQL and Sun have worked to optimize the performance of MySQL Network software certified for the Solaris 10 OS," said Zack Urlocker, vice president of marketing for MySQL AB. "This benchmark demonstrates Sun's continued leadership in delivering a world-class operating environment that provides excellent MySQL performance for our mutual enterprise customers."

I wonder if it means there were some changes to MySQL so it runs faster on Solaris?
In our internal tests MySQL on Linux (however older MySQL versions) was actually slightly faster than on Solaris - maybe we should re-check it. Unfortunately not much info on actual system tuning and disk config is reported (was ZFS used? how much IOs were generated, etc.).

Actual benchmark is here and official Sun announcement here.

T1000 arrived

T1000 has just arrived! You can expect some production performance numbers soon :)
As T1000 uses only two memory controllers out of 4 in US-T1 it could be slower than T2000 with the same CPU - I guess it could depend on application - we'll see how it's here.

Predictive Self Healing

Yesterday system which is E6500 with Solaris 10 reported few times memory errors (ECC corrected) on a board 0 dimm J3300.

Apr 18 17:45:30 server SUNW,UltraSPARC-II: [ID 197328 kern.info] [AFT0] Corrected Memory Error detected by CPU8, errID 0x0002de3b.e98a88fa
Apr 18 17:45:30 server     AFSR 0x00000000.00100000 AFAR 0x00000000.c709d428
Apr 18 17:45:30 server     AFSR.PSYND 0x0000(Score 05) AFSR.ETS 0x00 Fault_PC 0x11e7fe8
Apr 18 17:45:30 server     UDBL Syndrome 0x64 Memory Module Board 0 J3300
Apr 18 17:45:30 server SUNW,UltraSPARC-II: [ID 429688 kern.info] [AFT0] errID 0x0002de3b.e98a88fa Corrected Memory Error on Board 0 J3300 is Intermittent
Apr 18 17:45:30 server SUNW,UltraSPARC-II: [ID 671797 kern.info] [AFT0] errID 0x0002de3b.e98a88fa ECC Data Bit  7 was in error and corrected

As these errors happened few more times system finally removed single page (8kB) from a system memory so problem will not escalate and won't possibly kill system or application. Well, I can live with 8kB less memory - that's real Predictive Self Healing.

Apr 18 19:14:51 server SUNW,UltraSPARC-II: [ID 566906 kern.warning] WARNING: [AFT0] Most recent 3 soft errors from Memory Module Board 0 J3300 exceed threshold (N=2, T=24h:00m) triggering page retire
Apr 18 19:14:51 server unix: [ID 618185 kern.notice] NOTICE: Scheduling removal of page 0x00000000.c709c000
Apr 18 19:15:50 server unix: [ID 693633 kern.notice] NOTICE: Page 0x00000000.c709c000 removed from service

Booting from ZFS

Booting from ZFS was integrated in b37 which is available as SXCR right now. It's not a final solution - it's ugly but it's a beginning. The real fun will begin when GRUB will understand ZFS. You can see instructions on how to boot from ZFS in b37 at Tabriz's weblog.

T2000 scalability

Another benchmark showing T2000 scalability in various microbenchmarks and comparing it to 12-way (24 cores) E2900. Most of the benchmarks are HPC focused.

BrandZ DVD

SystemNews:

"If you are interested in downloading the SolarisTM Containers for Linux Applications functionality, BrandZ DVD 35 for the SolarisTM Operating System (Solaris OS) for x86 platforms is available now as a free download from the Sun Download Center. Based on SolarisTM Express build 35, this download is a full install of Solaris OS and includes all of the modifications added by the BrandZ project.

BrandZ is a framework that extends the SolarisTM Zones infrastructure to create Branded Zones, which are zones that contain non-native operating environments. Each operating environment is provided by a brand that may be as simple as an environment with the standard Solaris utilities replaced by their GNU equivalents, or as complex as a complete Linux user space. The brand plugs into the BrandZ framework.

The combination of BrandZ and the lx brand, which enables Linux binary applications to run unmodified on Solaris OS, is Solaris Containers for Linux Applications. The lx brand is not a Linux distribution and does not contain any Linux software. The lx brand enables user-level Linux software to run on a machine with a Solaris kernel, and includes the tools necessary to install a CentOS or Red Hat Enterprise Linux distribution inside a zone on a Solaris system.

The lx brand will run on x86/x64 systems booted with either a 32-bit or 64-bit kernel. Regardless of the underlying kernel, only 32-bit Linux applications are able to run.

As part of the OpenSolaris community, BrandZ is a hosted project on this open source web site that contains detailed information on BrandZ and the latest information on build 35."

ps. yes, this is continuation of the famous Janus project (LAE)

Solaris Internals & Debugging

Finally new book from authors of the old Solaris Internals book - actually two books. One (over 1000 pages) about Kernel Architecture in Open Solaris and Solaris 10 and the other one about Solaris Performance and Tools (yep, DTrace). This time there are three authors: Richard McDougall, Jim Mauro, Brendan Gregg. Judging from the last book they wrote these two already are a must have books.

More info here.

CPU caps

New way of CPU management - CPU caps. It allows you to set limits on applications (projects and zones) in a percentage of single CPU (although application can still use all CPUs). Right now this is available as a preview on Open Solaris Resource Management Project.