Test: Zfs «l2arc» with Intel SSD

Simple test to validate that my new SSD was not a waste of money. The test was made from a Windows xp virtual machine with iometer to generate I/O to a CIFS share on my file server “Solaris 11 Express”.

test	Test details	Test file size	L2arc SSD «in»	Average response time ms	iops	Explanation
1	Random 4k read	3GB	No	0.4	9517	3Gb fit in ram «arc»
2	Random 4k read	30GB	No	33.8	118	No ssd cache and 30GB is to big to fit in arc.. so I hit arc and the disk
3	Random 4k read	30GB	Yes	9.7	411	«l2arc» is configure and can contain 30GB but have to «warm»
4	Random 4k read	30GB	Yes	2.7	1482	Same as 3 but l2arc is warm
5	Random 4k read (more workers)	30GB	Yes	2.5	1625	Same as 4 but with more iometer workers

Test1

Test2

Test3

Test4

zpool iostat -v data

Test5

Another interesting post on the subject: http://blogs.sun.com/brendan/entry/test

Monitoring zpool with email alert «Solaris 11 Express»

Crontab job to scrub zpool once a week and check zpool status

45 3 * * 0 /usr/sbin/zpool scrub MydataZpool 45 3 * * 1 /usr/sbin/zpool scrub rpool 15 8 * * * /pathToperlScript/Zpool_check

Perl script to send email alert when zpool is not healthy

«Zpool_check»

#!/usr/bin/perl my $command_output = `zpool status -x`; if ($command_output eq "all pools are healthy\n") { print "all pools are healthy"; exit; } else { print "zpool not healthy"; $to='MYEMAIL@MYPROVIDER.com'; $from= 'alert@MYDOMAIN.COM'; $subject='zfs alert'; open(MAIL, "/usr/sbin/sendmail -t"); ## Mail Header print MAIL "To: $to\n"; print MAIL "From: $from\n"; print MAIL "Subject: $subject\n\n"; ## Mail Body print MAIL "Zfs alert \n"; print MAIL $command_output; close(MAIL); }

Configure sendmail if not already done...

Add this line to “/etc/mail/cf/cf/sendmail.mc”

DOMAIN(`solaris-generic')dnl define(`SMART_HOST', `SMTP.MYPROVIDER.com') define(`confFALLBACK_SMARTHOST', `mailhost$?m.$m$.')dnl

ZFS file server with Solaris 11

Why I choose zfs filesystem for my home file server

• Functionality (deduplication, encryption, compression, snapshot, replication, clone, iscsi target builtin, etc)
• Block level checksum (say goodbye to silent data corruption)
• Report read error and corrects it if you have a mirror or parity raid. (must have with ssd technology)
• Use ssd for intelligent “l2arc” caching
• Always consistent on disk
• Good startup to learn about zfs read: The last word in file systems http://www.sun.com/software/solaris/zfs_lc_preso.pdf
• Because it's cool to learn something new

Why don’t choose zfs for file server

• You don’t want to have a dedicated server for storage at home
• For standard home usage a cheap nas with raid1 do the job
• You’re a performance freak and just do sequential read and write and don’t care about silent corruption and zfs functionalities
• You don’t want to invest your time to understand and have fun with zfs

My zfs file server hardware

• Amd x2 5050e 45W
• Motherboard “SAPPHIRE PI-AM2RS780G”
• 8gb ram
• Intel pro 1000/100/10
• 1 x 250gb “For system boot... not in mirror yet”
• 3 x 1.5tb raidz “for data”
• 1 x 40gb intel ssd x25-v “For cache l2arc” Read my benchmark