… for the IO configuration I chose 8 x 200G EBS volumes in software RAID 10. Now let’s come to the…
Comment: Review of Virident FlashMAX MLC cards
April 24, 2012 By 14 Comments
… RAID-0 is that you end up with a corrupt volume even if no data loss occurs. if one of the…’t written for any operation this results in a corrupt volume. Therefore, even with the protections on the card with parity… failure to complete a write on RAID-0 corrupts the volume, even if no prior data was actually lost due to…
Comment: Review of Virident FlashMAX MLC cards
April 25, 2012 By 14 Comments
… Linux. I think this issue applies to any RAID-0 volume regardless of hardware or software platform. If even one drive… unable to write its portion of the data stripe, the volume is hopeless corrupted, even if the cause might be something…
Post: EC2/EBS single and RAID volumes IO benchmark
August 6, 2009 By 13 Comments
… perfect. So I have spent some time benchmarking volumes. Interesting part with EBS volumes is that you see it as device in… you can easily make software RAID from several volumes. So I created 4 volumes ( I used m.large instance), and made: RAID0… backup over EBS. On single EBS volume you can just do snapshot, but on several volumes it may be tricky. But in…
Post: Dissection of EC2 / EBS volume
August 7, 2009 By 4 Comments
… what IO characteristics we can expect from EBS volume ( I am speaking about single volume, not RAID as in my previous post… interesting behavior, there seems several level of caching on EBS volume. Let me show you. I did sysbench random read IO… setup, see my previous post EC2/EBS single and RAID volumes IO benchmark
Post: Storing MySQL Binary logs on NFS Volume
July 30, 2010 By 19 Comments
…. There are good reasons to have binary logs on NFS volume – binary logs is exactly the thing you want to survive… point in time recovery from backup. I was testing high volume replication today using Sysbench: sysbench –test=oltp –oltp-table-size… number was reachable even with binary log stored on NFS volume. This number is for sync_binlog=0 and innodb_flush…
Comment: LVM Configuration mistake to Avoid
July 10, 2008 By 10 Comments
… 3 hardware RAID1 volumes, giving a 146GB system volume and two 72GB data volumes. Finally we merged the two 72GB data volumes into one… snapshot for a logical volume must be done within the same volume group. Merging the two physical volumes into one volume group was no… result is that we stuck to two physical volumes, two volume groups and two logical volumes. We had to reduce the size of…
Post: Recovering Linux software RAID, RAID5 Array
August 27, 2011 By 2 Comments
… resynced (or failed first) you can check it examining all volumes separately: ReadyNAS1:~# mdadm –examine /dev/sdf3 /dev/sdf3: Magic : a92b4efc… Read ahead sectors 0 So we have RAID volume back but LVM shows this volume as NOT available and so it can… be easily fixed: ReadyNAS1:/# vgchange -a y 1 logical volume(s) in volume group “c” now active Lets check if the file…
Post: LVM Configuration mistake to Avoid
July 9, 2008 By 10 Comments
… enough space available on the volume…. The problem was internal and external volumes were configured as different “volume groups”. Volume groups in LVM live… should have done instead is creating single volume group and having RAID volumes as physical volumes. If you also have done such mistake…
Post: Death match! EBS versus SSD price, performance, and QoS
February 21, 2011 By 54 Comments
… week and now, they went from a 10-volume array to a 20-volume array, for example. But the samples I’ll… and wrote about half a megabyte per second from each volume, and got read latencies varying from the teens to the…. Note how variable the quality of service from these EBS volumes is — some are fast, some are slow, even though we…
