an open source approach to replication and recovery
TRANSCRIPT
An Open Source approach to replication and recovery.
Current Challenges:Miniscule IT Budgets.Backup Tapes don’t meet capacity needs or
are costly. Most RAIDs don’t protect from certain data
loss.Quick recovery of virtual disks and OS. Stuck with same vendor for offsite storage.
Vendor Specific SolutionsCostly; upwards of $60,000 for infrastructure.Offers features only available to like systems.Choose Two out of Three: Fast, Reliable, Cheap.Yearly support costs can damper most IT budgets.Typical useable storage capacity: 2.8TB with a single
shelf, the rest for snapshots and filesystem overhead.
An Open Source SolutionOpen Solaris with ZFS and iscsitarget
software.Relatively inexpensive compared to 3rd party
vendorsCan mix and match hardware.ZFS: Virtually unlimited capacity!Technical creativity when building scripts.
Cons about Opensolaris iSCSINot supported by VMware. (yet)OS and Filesystem Learning curve Limited to 1gb/s of bandwidth per SAN*
(until 10gb/s is released)No support for MTU 9000 (Jumbo Frames)
Necessary Tools for success.ZFS File System; /sbin/zpool and /sbin/zfs;
snapshotsIscsitadm (pkg add)SSH keygen/pgpA replication script (e.g. zfs-replicate.sh)CronMailEnable Vmware LVM/snapshot
What is Zpool/ZFS?ZFS is a file system designed by Sun Microsystems for the
Solaris Operating System. Features include support for high storage capacities (16 exabytes per pool or 16 million terrabytes), snapshots and copy-on-write clones, continuous integrity checking (256bit CRC checks of every block) and automatic repair (scrubbing), RAID-Z and ACLs. (Found on Wiki)
http://opensolaris.org/os/community/zfs/whatis/RAID 0 – 5: No protection against silent disk corruption and
bit rot. http://blogs.sun.com/bonwick/entry/raid_zZpool: disk pool creation, iostatus, and health display (build
RAIDZ, RAIDZ2, Jbods, stripes, mirrors, striped mirrors, etc…)
Open Solaris iscsitargetUses industry standard iscsi target and initiator
callsExtremely easy to use and seamlessly integrates
with Zpool/ZFSAllows for the creation of soft provisioned disks. ACL support, deny unwanted initiators.Iscsitadm list targets –v : details of each currently
active targets
Replication Script; Mail; CronMany available on the internetModified a script from the web (author
unknown) to work according to my requirements. Still in progress but works . (zfs-replicate.sh)
Use Cron to execute zfs-replicate on a schedule.
Mail the results to your disk admins.
Vmware EnterpriseConfigure VMWare for iSCSI supportAdd targets to Vmware host adapters.Enable LVM snapshot support: GUI far more
simpler than console.
Snapshots: How to?Reserve up to 40% of maximum pool capacity for
snapshots, i.e. 10TB pool, 6TB data, 4TB snapshots. Admin discretion and may be less depending on LUN configuration.
Snapshots are the size of the used capacity of the LUN/partition.
Making a snapshot is a breeze! /sbin/zfs snapshot pool/partition@snapshot
Send the snapshot over to the remote site. /sbin/zfs send pool/partition@snapshot | ssh username@host \
/sbin/zfs recv pool/partition
Replication types ZFS send/recv with SSH (avg. speed: 25MB/s at 256bit encryption)
Slowest replication, doesn’t require dedicated network and secure. Different algorithms provide different data throughput. Stunnel may be quicker!
ZFS send/recv with mbuffer (speeds: 80 to 120MB/s Avg: 360Gig/hr) lev@siscsi-sas:~$ zfs send sd/Linux@1 | mbuffer -b1024k -m 1500m -O
172.32.66.10:9999 ;LOCAL SITE lev@piscsi-sas:~$ mbuffer -m 1500M -s1024k -I 172.32.66.11:9999 | zfs recv
pdrive/Linux ;REMOTE SITE http://www.maier-komor.de/mbuffer.html
Must have enough system memory (+4GB) to support large buffers. Non encrypted, requires network paths to be safe.
ZFS send/recv with netcat/rsh (avg. speed: 35MB/s) Insecure data copy, just for comparison.
Data RecoveryActivate offsite VM ESX Host.Access offsite disk storage LUNs.
add iSCSI remote host to Virtual CenterRe-add VM Disk (LUNs) to offsite VM Infrastructure.
GUI: Advanced Features: LVM: EnableResignature CLI: /proc/vmware/config/LVM/EnableResignature
Resignatured LUNs will appear automatically in the storage section of Virtual Center.
Re-add VM Guests from resignatured LUNsOffsite LUNs can be added to primary VM site for data
recovery or testing...
