最後更新: 2023-03-10

目錄

• 注意事項
• 新式指令
• Scrub
• Kernel threads
• Recovery
• Build btrfs-progs
• extref(extended inode refs)
• More about btrfs
• 建立多 Device 的 btrfs (mkfs.btrfs)
• RAID1 Usage
• Conversion (single -> raid1)
• Replacing failed devices
• Play btrfs with image file
• btrfs-send / btrfs-receive
• GlobalReserve
• XOR module
• 常遇到的應用
• Data Integrity Test

介紹

btrfs 是一個多才多藝的 FileSystem 來, 它核心架構是 CoW, 支援以下功能:

• Extent based file storage (2^64 max file size = 16EiB)
• Dynamic inode allocation
• Writable snapshots
• Subvolumes (internal filesystem roots)
• Subvolume-aware quota support
• Object level mirroring and striping
• Compression (ZLIB, LZO)
• Online filesystem defragmentation
• Integrated multiple device support (RAID0, RAID1, RAID10, RAID5 )
• Checksums on metadata and data (crc32c, xxhash, sha256, blake2b)
• Space-efficient packing of small files
• Space-efficient indexed directories
• Seed devices
  (Create a readonly filesystem that acts as a template to seed other Btrfs filesystems)
• Background scrub process for finding and fixing errors on files with redundant copies
• Efficient incremental backup(btrfs send)

所以說, 唔用就走寶 ~

不過, 使用前一定要少心, 因為在 Linux2.6 上它仍未有 fsck !! (Linux 3.2 上的 btrfsck 仍未用得..)

此外, 如果 CPU 支援 hardware 的 CRC32 那效能會更好
(grep -i SSE4.2 /proc/cpuinfo)

Version

每 version 的改善: btrfs_version

最後更新: 2019-08-14

目錄

• 介紹
• open-iscsi
• tgtd
• iscsitarget

介紹

iscsi 的 initiator 一共有兩類:

last update: 22-8-11
 

User mode
    qemu linux.img

System mode
    qemu-i386 -L / /bin/ls

apt-get install qemu qemu-utils

qemu
qemu-img
 

建立 image

qemu-img create -f qcow2 hda.img 10G 

Default cluster_size: 65536

啟動

qemu -hda c.img -cdrom linux.iso -boot d -m 128 -localtime -vnc,password -monitor stdio

-monitor stdio 在 cmd mode 下見到 monitor

last update: 22-8-11
 

Network:

• iproute: tc, ss, ip, arpd, nstat, lnstat, rtmon
• dnsutils: dig, nslookup, nsupdate
• traceroute
• telnet
• net-tools: arp, mii-tool, route, ifconfig, rarp
• whois
• nmap
• iftop
• lftp
• tcpdump
• mailutils
• lynx
• curl
• wget
• iputils-ping    <--- ping

FileSystem:

• fuse-utils
• sshfs
• quota
• quotatool