I attended the Atlanta area OpenSolaris Meetup last night even though we were getting some major rain in the area which made the 30 minute drive challenging. Why would I bother? Swag? Scott D presenting? Being around other nerds that like Solaris? No, although those are all valid reasons too.
Even with the nasty weather, the room was packed and we had to bring in some more chairs so everyone could sit. About 20 people attended.
New stuff in ZFS
Yep, the entire meeting was about fairly new features added to ZFS on OpenSolaris. Things like data deduplication and how well it works in normal and extreme situations. The main things I took away from the talk were:
- ZFS is stable
- Data Deduplication, dedup for short, should only be used on backup areas, not on live production data, until you become comfortable with it and the performance in your environment
- Dedup happens at the block level of a zpool, anything above that level still works as designed
- Only use builds after 129 of OpenSolaris if you plan to use dedup. Earlier versions had data loss issues with the code.
- Solaris doesn’t have the dedup code yet. It is not currently scheduled for any specific release either.
- DeDup is only available in real-time now, there is no dedup thread that can be scheduled to run later. This could have unknown performance impacts (good or bad).
- ZFS supports both read and write cache devices. This means we can specify cheap and expensive SSD memory be used for caching either cache and deploy cheaper, larger SATA disks for the actual disk storage. Some cost/performance examples were shown with 10,000rpm SAS drives compared to SSD cache with 4200 SATA drives. The price was about the same, 4x more storage was available and performance was 2x better for read and about the same for write. Nice.
- ZFS has added a way to check for disk size changes – suppose your storage is external to the server and really just a logical allocation. On the storage server, you can expand the LUN that the server sees. ZFS can be configured to manually or automatically refresh disk device sizes.
- Device removal – currently there is no direct method to remove the disk from a ZFS pool. There are work arounds, however. Anyway, they are planning to release the method this year in OpenSolaris ZFS to remove a disk from a zpool.
To really get the demo, you need to accept the other great things about ZFS as a basis, then add the new capabilities on top. One of the demonstrations was how IT shops can charge back for data storage to multiple users since they are using the data, even when 20 other departments are also using the same data blocks. Basically, dedup gives you more disk storage without buying more disk.
ACLs are managed at the file system level, not the disk block level, so the dedup’ed data still can only be accessed appropriately.
Why OpenSolaris ?
Is an open source version of Sun Microsystems Solaris operating systems that runs on lots of hardware you may already own. It also runs inside most virtual machines as a client or guest. Since it looks and feels like Solaris, you can become familiar with it for zero cost on your PC at home for just the cost of disk storage – about 20GB. Sun also uses OpenSolaris to trial new features prior to placing them into the real Solaris releases. I run OpenSolaris in a virtual machine under Widnows7 using the free version of Sun’s VirtualBox hypervisor. I know others who run it directly on hardware, under Xen and under VMware hypervisors too. Just give it enough virtual disk storage and go. I think 10GB is enough to load it, but a little more, say 20GB, will let you play with it and applications more.
If you are in the market for NetApp storage, you really need to take a look at Sun’s storage servers running ZFS. The entry price is significantly less and you get all the flexibility of Solaris without giving up CIFS, iSCSI, NFS, and, in the future, fibre channel storage. Good sales job Sun.
No meetup is a success without some swag. Water bottles, t-shirts, hats, and books, were all available. We were encouraged to take some after the iPod Nano raffle was won (not by me). Pizza and sodas were also provided by the sponsors.
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